WO2025006775A1 - Smart fibers for medical devices - Google Patents

Abstract

Disclosed are antenna fiber sensors and systems incorporating the sensors, methods of making the sensors, and methods of using the sensors. The sensor is a thermoplastic elastomeric polymer cladding enclosing metal wires thermally co-drawn into an antenna fiber. Further, the sensors are used with an RF generator to monitor electromagnetic pulse along the transmission line and measure location along the fiber. The antenna fiber sensor provides sensitive distributed pressure, temperature, and proximity measurements for various procedures and interfaces, particularly medical procedures such as vascular operations.

Description

Docket No. 144578.00411  SMART^FIBERS^FOR^MEDICAL^DEVICES^ ^ Cross^Reference^to^Related^Application^ ^{[0001] The present application claims priority to U.S. Provisional Patent Application} _{No. 63/510,493 that was filed June 27, 2023, the entire contents of which are hereby incorporated by reference in its entirety.^^} ^ Technical^Field^ ^{[0002] The disclosure relates to smart fiber antenna sensors, for sensing parameters} _{such as pressure, proximity, and temperature at locations along their length.} Background ^{[0003] Imbuing sensing and processing capabilities to the material objects enables their integration as active nodes into the Internet of Things (IoT) and recreating their digital twins in a metaverse. Specifically, fibers and textiles with data sensing and processing capabilities have conformal properties that allow imbuing them as part of a thin coating or as an upholstery to the surface of any existing object with an arbitrary 3D surface shape. Due} _{to its thin, flexible, and elastic form-factor, incorporation of the sensory fiber, or the sensory textile comprised of multiple interweaved fibers, onto the surface of a functional object can be done seamlessly, without modifying or hindering preexisting functionality of the object, while turning the entire surface of the object into a distributed sensory matrix, tactile and reactive to its environment, like the skin of living organisms.} ^{[0004] Medical devices are one area in which advanced sensor technology may be applied. Medical treatments and surgical operations have a variety of challenges even with advancements over conventional sensing technology, such as complex integration into devices during the manufacturing process, challenges with visualizing the position of a single sensor leading to extended procedure times and over-exposure to radiation, accurate real-} _{time data collection, and not having quantifiable verification of intraprocedural treatment success. Additionally, most of the sensing devices are stand alone, well delineated macroscopic or mesoscopic objects at least partly made of hard materials, such as plastics, metals, and semiconductors. As such, when integrated into a medical device, they might} Docket No. 144578.00411  ^{significantly modify its geometry, formfactor, and biomechanical compatibility with the environment (living tissue) into which they are implanted or introduced, resulting in diminished overall short-term device performance, or increasing the risk of inflammation, scarring, or rejection of the device, thus hindering its long-term use. Thin, flexible, elastic,} _{and biocompatible sensing fibers that can provide distributed monitoring of parameters such as pressure, spatial proximity, and temperature, particularly while moving in a blood vessel or other body cavity during medical procedures, are needed to overcome some of the current challenges.} ^{[0005] A novel development in soft electronics pioneered flexible sensors, replacing conventional sensors in several applications, including health care. Their unique properties in sensing, monitoring, and human-machine interfacing make them an ideal replacement for conventional sensors. Wearable sensors, electronic skins, flexible textiles, and soft fiber} _{sensors are substantial improvements in soft electronics, where physiologic monitoring is facilitated by high sensitivity, resolution, accuracy, and comfort. Specifically, smart fibers are excellent candidates for novel sensors which provide enhanced functionalities in complex, miniaturized structures such as distributed measurements.} ^{[0006] The human vascular system is a complex, branched network consisting of various diameter vessels. Blood pressure is one of the fundamental parameters in physiologic monitoring. Measurement accuracy is vital for many diagnoses and treatments, such as minimally invasive operations that use guidewires and catheters to access the vascular system in order to treat cardiac conditions, such as angioplasty and cardiac ablation.} _{Existing solutions commonly used in these operations provide single-point pressure measurements with embedded pressure sensor(s) along the tip of the device, which are challenging to manufacture and limited in the data that can be provided. Distributed pressure sensor fibers bring an innovative approach to multipoint measurements where fibers are capable of measuring pressure in multiple locations with high sensitivity and resolution.} Summary^ ^{[0007] The present disclosure addresses the above drawbacks by providing fibers,} _{systems, and method for distributed sensing of parameters such as pressure, proximity, and} Docket No. 144578.00411  ^{temperature at any point along the length of the fibers, in order to provide real-time} _{feedback to a user.} ^{[0008] According to an aspect of the present disclosure, an antenna fiber sensor is described comprising a polymer cladding with an outer surface, a length extending between a proximal end and a distal end along a first axis, a width, and a thickness; one or more pores surrounded by the polymer cladding and distributed between the proximal end and the} _{distal end of the cladding, and one or more wires extending within the polymer cladding and between the proximal end and distal end of the cladding. The polymer is a composite of thermoplastic elastomer and a dielectric-constant modifying filler. The one or more pores has a diameter less than the width and thickness of the polymer cladding.} ^{[0009] According to another aspect of the present disclosure, an antenna fiber sensor system is described, comprising: i) the antenna fiber sensor; ii) a radio frequency (RF) generator and receiver; and iii) passive or active electronics coupling the RF} _{generator/receiver to the antenna fiber sensor for the choice of the electromagnetic (EM) mode combination. The passive or active electronics coupling allows choosing or invoking the respective sensing modalities.} ^{[0010] A further aspect of the present disclosure are methods of sensing using the disclosed antenna fiber. An aspect is a method for sensing within a vessel using the antenna fiber system that includes inserting the antenna fiber sensor into a vessel; transmitting an electromagnetic signal from an RF generator; receiving a reflected electromagnetic signal at} _{the RF receiver; detecting impedance changes in the reflected electromagnetic signal; converting the detected impedance changes in the reflected electromagnetic signal into a change in characteristic of the antenna fiber sensor; and detecting the location of the change in characteristic along the antenna fiber sensor.} ^{[0011] According to another aspect of the present disclosure, a method of making an antenna fiber sensor is described. The method includes the steps of: producing a polymer cladding preform including one or more channels and one or more passages, and thermally} _{drawing the polymer cladding preform with one or more wires feeding into the one or more passages. In the methods, the polymer cladding is a composite of a thermoplastic elastomer and a dielectric-constant modifying filler.} Docket No. 144578.00411  Brief^Description^of^the^Drawings^ ^{[0012] FIGS 1A-1C are schematics of the antenna fiber sensor. FIG.1A is a schematic of an example antenna fiber sensor, according to aspects of the present disclosure. FIG.1B is a schematic of the example antenna fiber sensor of FIG. 1A acted on by stresses P1 and P2 along the length of the sensor, illustrating a stress-sensing mode of operation based in the} _{local distortion to the propagating mode refractive index involving fiber deformation. FIG. 1C is a schematic of the antenna fiber sensor of FIG. 1A experiencing a local distortion to the propagating mode refractive index by an insertion of a foreign object into the mode’s electric field.} ^{[0013] FIGS. 2A-2H illustrate an antenna fiber sensor system. FIG. 2A is an example antenna fiber sensor system according to aspects of the present disclosure. FIG. 2B is a schematic of the components of an example antenna fiber sensor system according to aspects of the present disclosure. FIG. 2C is an electromagnetic pulse waveform that is sent by an RF generator and the received waveform that indicates voltage changes based on deformation points along an example antenna fiber sensor system, according to aspects of the current disclosure. FIG.2D is a schematic of an example antenna fiber system and applied pressure at multiple points of the fiber by a finger corresponding to the waveforms of FIG.} _{2C. FIG. 2E is an exemplary cross-section of the antenna fiber sensor including the shapes (Sh(x,y)) and refractive indices (n) of the cladding, core, and electrodes, according to aspects of the current disclosure. FIG. 2F is a schematic of an example embodiment of a multi- material fiber antenna with 1 mm diameter, doped glycerol liquid core, and copper wires, according to aspects of the present disclosure. FIG. 2G is a schematic of an example embodiment of a multi-material fiber antenna with 1 mm diameter, air-filled core, and copper wires. FIG. 2H is a schematic of an example embodiment of a multi-material fiber antenna with 0.4 mm diameter, air-filled core, and tungsten wires.} ^{[0014] FIGS. 3A-3C illustrate modes of an antenna fiber sensor. FIG. 3A is a schematic of an example asymmetric mode in a two-wire antenna fiber sensor for pressure sensing, according to aspects of the present disclosure. FIG. 3B is a schematic of an example} _{symmetric mode in a two-wire antenna fiber sensor for proximity sensing, according to aspects of the present disclosure. The red and blue arrows in FIG. 3A and 3B show schematically the direction and magnitude of the electric field at the electrode-cladding} Docket No. 144578.00411  ^{interfaces, the green arrows are the direction and magnitude of the electric field created by} _{the mode in the fiber and its surrounding. FIG. 3C shows plots of the superposition results of symmetric and asymmetric modes for simultaneous pressure and proximity sensing.} ^{[0015] FIG. 4 is a schematic illustrating the processing by the returned signal to a} _{time-domain reflectometer (TDR) for analyzing the location and sensed measurement on the antenna fiber sensor, according to aspects of the current disclosure.} ^{[0016] FIGS. 5A-5C illustrate sensing methods with the antenna fiber sensor. FIG. 5A is a schematic of two sensing methods either by (i) changes in capacitance by fiber deformation or by (ii) changes in the fiber’s refractive index by changing dielectric constant as a result of a foreign object penetrating the fiber’s evanescence field, according to aspects of the current disclosure. FIG. 5B is a schematic of electronic testing methods for (i) fiber deformation, (ii) proximity measurements, and (iii) distributed measurement setup with} _{multiple weights at multiple points along the length of a fiber, according to aspects of the current disclosure. FIG.5C illustrates electromagnetic simulation of an air-filled core copper wire antenna fiber sensor using COMSOL Multiphysics software where (i) shows the electrical field norm of the fiber on the vertical axis, (ii) shows the COMSOL simulation of electrical field of a 1 mm fiber, and (iii) shows the electrical field norm of the fiber on the horizontal axis, according to aspects of the current disclosure.} ^{[0017] FIGS. 6A-6B illustrate connection of an antenna fiber sensor to a radio frequency (RF) system. FIG. 6A is schematic of a socket for connecting the wires to the RF-} _{generator and receiver of an example antenna fiber sensor system. FIG. 6B shows images of the steps of inserting the wires in the socket for connecting to an RF-generator and receiver, according to aspects of the present disclosure.} ^{[0018] FIG.7 shows images of a measurement setup for the capacitance measurement of glycerol and BaTiO3 nano-powder doped glycerol at different distances between the} _{parallel plates of a Hippotronics OC-TC Oil Tester for the measurement cell using an LCR Meter (Hioki 3536 LCR Meter), according to aspects of the present disclosure.} ^{[0019] FIGS. 8A-8C illustrate capacitance measurement for doped and undoped glycerol. FIG. 8A illustrates the capacitance of undoped and BaTiO3 nano-powder doped} _{glycerol as measured by the setup in FIG. 7. FIG. 8B is a plot illustrating the complex impedance amplitude measurements of undoped glycerol and BaTiO3 nano-powder doped} Docket No. 144578.00411  ^{glycerol at different distances between the parallel plates in the measurement cell of FIG. 7 using an LCR Meter (Hioki 3536 LCR Meter). FIG. 8C is a plot illustrating the complex} _{impedance phase angle measurements of undoped glycerol and doped glycerol at different distances between the parallel plates in the measurement cell of FIG. 7 using an LCR Meter (Hioki 3536 LCR Meter).} ^{[0020] FIGS. 9A-9C illustrate an antenna fiber sensor wire and core elements. FIG. 9A is a schematic of an antenna fiber sensor with copper wires and a glycerol-filled core (Cu- Gly) (i) and its associated sensitivity curve (ii) and distributed pressure measurement (iii), according to aspects of the present disclosure. FIG. 9B is a schematic of an antenna fiber} _{sensor with copper wires and an air-filled core (Cu-Air) (i) and its associated sensitivity curve (ii) and distributed pressure measurement (iii), according to aspects of the present disclosure. FIG. 9C is a schematic of an antenna fiber sensor with tungsten wires and an air- filled core (W-Air) (i) and its associated sensitivity curve (ii) and distributed pressure measurement (iii), according to aspects of the present disclosure.} ^{[0021] FIGS. 10A-10B illustrate associated measurement with an antenna fiber sensor. FIG. 10A is a schematic of a 1 mm Cu-Air antenna fiber sensor and its associated pressure sensitivity limit measurements with sub-gram weights. Load of 0.1 g translates into} _{pressure of 0.1 kPa, 0.2 g into 0.2 kPa, etc.. FIG. 10B is a schematic of a 0.4 mm miniaturized W-Air antenna fiber sensor and its associated proximity measurements, using metallic objects of increasing diameter (color coded in graphs) brought to 4 mm from the fiber.} ^{[0022] FIGS. 11A-11C illustrate signal measurement with the antenna fiber sensor. FIG.11A is a schematic of a Cu-Gly antenna fiber sensor (panel a) and a plot of its associated full-width at half-maximum (FWHM) and amplitude of the signal at 6, 16, 26, and 36 cm using a 20 g weight (FWHM of 4-6.5 cm) (panel b). FIG.11B is a schematic of a Cu-Air antenna fiber} _{sensor (panel a) and a plot of its associated FWHM and amplitude of the signal at 6, 16, 26, 36, and 46 cm using a 20 g weight (FWHM of 1.15-1.4 cm) (panel b). FIG. 11C is a schematic of a W-Air antenna fiber sensor (panel a) and a plot of its associated FWHM and amplitude of the signal at 6, 16, 26, 36, and 46 cmusing a 10 g weight (FWHM of 1.2-2.7 cm) (panel b).} ^{[0023] FIGS 12A-12D illustrate pressure measurement with an antenna fiber sensor.} _{FIG. 12A is a schematic of a measurement setup for hydrostatic pressure measurements, in} Docket No. 144578.00411  ^{which the fiber vertically oriented is partly immersed in the liquid, and the liquid is gradually} _{added to cover a longer section of a fiber.} ^{[0024] FIG. 12B is a plot of hydrostatic measurement results of Cu-Air antenna fiber sensor within a fluid column of deionized water at different levels, covering an increasing fiber height. The RF electronics is coupled to the antenna fiber sensor invoking all the sensing modalities simultaneously. The pronounced step in the signal at the water-air interface is due to the symmetric mode sensing the jump in the dielectric constant at the water-air} _{interface, i.e., substance identification. Additionally, the signal baseline of the section immersed in water decreases as the longer section of the fiber is immersed, indicating an increase in average hydrostatic pressure in the immersed section, sensed by antisymmetric mode. FIG.12C is a plot of linear approximation of the hydrostatic pressure measurements from the measurement setup and results of FIGS. 12A-12B.} ^{[0025] FIG. 12D is a schematic of the measurement setup for hydrostatic and hydrodynamic pressure measurement. The entire fiber is immersed in water, and increasing} _{the reservoir height can change the column pressure. The fiber is inserted into the 3D- printed tube with periodically changing diameters, simulating vasculature with cloth-inlaid sections.} ^{[0026] FIG. 12E is set of plots illustrating the change in column pressure. When the} _{tubing in FIG. 12D is sealed, the change in column pressure results in a uniform change in the hydrostatic pressure signal.} ^{[0027] FIG. 12F is set of plots illustrating the change in column pressure. When the tubing in FIG. 12D is open, the change in the column pressure results in increasing differential pressure change, overlayed on the jumps in pressure at the locations of changing the inner diameter of the vasculature model, as is indicated in FIG. 12F (left). After} _{subtracting the average pressure drop between the water column and air, its apparent that, according to Bernoulli’s principle, the pressure in hydrodynamic conditions is lower in the section of the vasculature model that has a smaller inner diameter (FIG 12 F (right)), i.e. in hydrodynamic conditions the fiber is capable of locating cloth-inlaid pre-ischemic blood vessel sections with high specificity.} ^{[0028] FIGS. 13A-13C illustrate temperature measurement with an antenna fiber} _{sensor. FIG. 13A shows a temperature measurement setup with antenna fiber sensors,} Docket No. 144578.00411  ^{according to aspects of the present disclosure. FIG. 13B is a plot and thermal image of an} _{antenna fiber sensor with a glycerol core doped with BaTiO3. FIG. 13C is a plot and thermal image of styrene-ethylene-butylene-styrene (SEBS) cladding.} ^{[0029] FIG.14 is a flowchart of the steps for using an antenna fiber sensor for sensing} _{pressure, according to aspects of the current disclosure.} ^{[0030] FIGS. 15A-15C illustrate thermal drawn antenna fiber sensor. FIG. 15A is a schematic of the thermal drawing process of the antenna fiber sensor preform with the infill of doped glycerol by a syringe. FIG. 15B shows microscopy images of cross-sections of a Cu-} _{Gly antenna fiber sensor (i), Cu-Air antenna fiber sensor (ii), and a miniaturized W-Air antenna fiber sensor (iii), according to aspects of the current disclosure. FIG. 15C shows spooled fiber of the Cu-Gly antenna fiber sensor (i), the Cu-Air antenna fiber sensor (ii) , and the W-Air antenna fiber sensor (iii).} ^{[0031] FIG. 16 illustrates an example method of forming elastomer cladding doped} _{with nanofiller, in which BaTiO3 nanoparticles are premixed with SEBS to form a composite sheet for the cladding elastomer.} ^{[0032] FIG. 17 illustrates an example method of forming glycerol doped with BaTiO3} _{nano-powder by manual and magnetic stirring.} ^{[0033] FIG. 18 depicts a transparent SEBS polymer sheet prepared by melting} _{polymer pellets (left) into sheets (right).} ^{[0034] FIG. 19 illustrates a preform in a vacuum oven arranged for consolidation of SEBS polymer sheets. The white rods and blocks are to confine the preform structure from} _{sagging or collapsing and apply a light pressure in order to assist the consolidation.} ^{[0035] FIGS. 20A-20B illustrate a SEBS polymer preform. FIG. 20A illustrates a top} _{view of a SEBS polymer preform after consolidation. FIG.20B illustrates a side view of a SEBS polymer preform after consolidation.} ^{[0036] FIGS. 21A-21B illustrate SEBS polymer preform printing. FIG. 21A shows a three-dimensional (3D) printing process of SEBS polymer preform, according to aspects of} _{the present disclosure. FIG. 21B illustrates 2 cm wide square preform with hollow channel and two holes for the wires, side (left) and top (right) view.} ^{[0037] FIGS. 22A-22D illustrate a fiber draw process. FIG.22A is a typical preform for} _{draw arrangement with two spools of 75 µm copper wires. FIG. 22B is a side view of the} Docket No. 144578.00411  ^{preform (~2 cm wide) and copper wires on the preform holder of FIG. 22A. FIG. 22C is A} _{preform after the draw is finished. FIG.22D is a spool of typical fiber (~0.5 mm thick) resulting from the draw process.} ^{[0038] FIGS. 23A-23D illustrate a fiber drawing system. FIG. 23A is a cross-sectional view of a preform being inserted into a fiber drawing system. FIG. 23B is a cross-sectional} _{view of a preform being heated in a fiber drawing system. FIG. 23C is a cross-sectional view of a beginning of a fiber draw in a fiber drawing system. FIG. 23D is a cross-section view of a fiber draw in a fiber drawing system.} ^{[0039] FIGS. 24A-24B illustrate methods for creating the liquid-filled core of an antenna fiber sensor. FIG. 24A shows incorporation of liquid into a hollow core via manual} _{injection. FIG. 24B shows the incorporation of liquid into a hollow core via suction of the liquid from an open syringe during drawing.} ^{[0040] FIGS. 25A-25B illustrate corresponding parameters for fiber drawing with liquid-filled core. FIG. 25A is a plot of drawing parameters (diameter, speed) of liquid} _{glycerol in SEBS. FIG. 25B is a plot of drawing parameters (tension, temperature) of liquid glycerol in SEBS.} ^{[0041] FIGS. 26A-26B illustrate variation for antenna fiber sensor fabrication. FIG. 26A shows a setup for fabrication of an antenna fiber sensor in which the hollow core is} _{periodically collapsed or broken up using 2 cm magnets. FIG. 26B shows a collapsed area of the antenna fiber sensor using the setup of FIG. 26A.} ^{[0042] FIG. 27 is a schematic of the optimization for reducing the interfacial tension} _{between a viscous liquid core preserved in another viscous liquid, from the core’s cylindrical volume and its breakup into periodic spheres during the breakup process.} ^{[0043] FIG. 28 illustrates the evolution of a breakup of the core between two} _{polymers, according to aspects of the present disclosure.} ^{[0044] FIGS. 29A-29C illustrate the breakup of doped glycerol corecontinuously fed through a hot furnace of a tapering setup vs. heated on the hot plate. FIG. 29A shows the as-} _{drawn fiber. FIG 29B illustrates the wavy pattern showing the beginning but incomplete process of breakup of the fiber fed through a furnace), and FIG. 29C illustrates the breakup of doped glycerol core using a hot plate.} ^ Docket No. 144578.00411  Detailed^Description^ ^{[0045] Described are antenna fiber sensors and antenna fiber sensor systems for sensing pressure from forces on the fiber and objects near the fiber at positions along the fiber length, methods of making the antenna fiber sensors, including fabricating the fibers by thermal drawing technique, and methods for sensing using the antenna fiber sensors, for example, pressure, temperature, proximity of an object, and location in the surrounding} _{environment. Methods of sensing may include using TDR analysis, for example, to collect high-resolution distributed pressure measurements. For instance, a possible clinical use of the antenna fiber sensor includes locating with high specificity the cloth-inlaid reduced inner diameter pre-ischemic sections of blood vessels in 3D printed models, while used in stress- sensing antisymmetric-mode coupled configuration. Further, the antenna fiber sensor may be used for material identification.} [0046] Sensor ^{[0047] Referring to FIG. 1A, a non-limiting example, the antenna fiber sensor 100 is a fiber with a polymer cladding 102 extending between a proximal end and a distal end. The polymer cladding 102 of the antenna fiber sensor may be made of polymer with high level of elasticity which provides maximum deformation by compression of the sensor. In a non-} _{limiting example, the polymer is a thermoplastic elastomer. For example, the thermoelastic polymer may be one of, but is not limited to, styrene-ethylene-butylene-styrene (SEBS), cyclic olefin copolymer (COC), elastomeric cyclic olefin copolymer (ECOC), polysulfone (PSU), poly(methyl methacrylate) (PMMA), polycarbonate (PC), polyvinylidene fluoride (PVDF), polyetherimide (PEI), or polydimethylsiloxane (PDMS).} ^{[0048] The polymer cladding 102 of the antenna fiber sensor 100 may further be a composite of a polymer, such as the thermoplastic elastomers described previously, and a dielectric-constant modifying filler. In a non-limiting example, the composite may include 0% to 50% of the dielectric-constant modifying filler by volume. The amount of filler may be tuned to achieve a desired mean field dielectric constant εf. In a non-limiting example the} _{dielectric-constant modifying filler may be one of, but not limited to, ferroelectric oxides including barium titanate (BaTiO3) and strontium titanate (SrTiO3), metal and transition metal oxides including Calcium copper titanate (CaCu3Ti4O12), La2−xSrxNiO4, and derivates thereof, intrinsic or doped semiconductors including silicon (Si), germanium (Ge),} Docket No. 144578.00411  ^{and gallium antimonide (GaSb), or conductors including silver (Ag) and carbon (C). In a non- limiting example, the dielectric-constant modifying filler has a particle size range of 10 nm –} _{500 nm. In a preferred embodiment, the particle size of the dielectric-constant modifying filler is 50 nm – 200 nm.} ^{[0049] In a non-limiting example, the polymer cladding 102 houses one or more wires 104. The wires may extend the length of the sensor. In a non-limiting example, the wires may be metal or conductive polymer composite. In a non-limiting example, the metal wires may include a metal with a melting point greater than 400 °C. In another non-limiting example, the melting point of the wires is higher than the softening point of the cladding. The metal} _{may include, but is not limited to, copper (Cu), zinc (Zn), silver (Ag), or tungsten (W). In a non-limiting example, the conductive polymer wires may be, but are not limited to, carbon black-doped polycarbonate (CPC), carbon black-doped polyvinylidene fluoride (PVDF), carbon black-doped polyetherimide (PEI), carbon nanotube-doped CPC, carbon nanotube- doped PVDF, carbon nanotube-doped PEI, or combinations thereof.} ^{[0050] In a non-limiting example, the antenna fiber sensor 100 further includes one or more pores 106 surrounded by the polymer cladding 102. The one or more pores 106 may be hollow, filled, partially filled, or any combination thereof based on achieving a desired field dielectric constant ε2. As will be described in further detail, the one or more pores or channels are added, introduced, or formed within the polymer cladding, such as during the formation of the antenna fiber sensor 100. The one or more pores 106 may be enclosed within the cladding and do not extend to the outer surface of the polymer cladding.} _{Further, the one or more pores 106 may be distributed throughout the cladding. The pores may be distributed throughout the length of the sensor cladding 102. Alternatively, the pores 106 may be one or more channels extending the length of the polymer cladding 102. Alternatively, the pores 106 may be channels that extend at least a partial length of the polymer cladding 102. For example, the channels may extend the full length between the proximal and distal end of the cladding. In the embodiments, the one or more channels do not extend to the outer surface of the polymer cladding. The one or more channels may alternatively be referred to as cores herein.} ^{[0051] The introduction of pores or channels into the cladding makes it deformable} _{under hydrostatic and hydrodynamic conditions, which is critical for the successful} Docket No. 144578.00411  ^{applications in the medical realm, such as for local sensing of changes in vascular blood} _{pressure in pre-ischemic blood vessels or in bodily liquids in locally partly obstructed urinary tract, as is described herein.} ^{[0052] In a non-limiting example, the one or more pores 106 may be filled or partially filled with one of a gas or a liquid. For example, the gas may include nitrogen, oxygen, or inert gases such as helium or argon. Alternatively, the one or more pores 106 may be filled with a} _{colloidal liquid. For example, the colloidal liquid may include, but is not limited to, glycerol or polyethylene glycol doped with a high dielectric constant filler. In a non-limiting example, the high dielectric constant filler is BaTiO3 or SrTiO3.} ^{[0053] In a non-limiting example, one or more pores 106 are distributed along the length of the antenna fiber sensor 100 and one or more wires 104 extend along the length of the sensor. The one or more pores 106 may be parallel to the one or more wires 104. For} _{example, where the one or more pores are one or more channels, the one or more channels and the one or more pores extend the length of the sensor in parallel to each other.} ^{[0054] In a non-limiting example one pore or one channel may be transversely} _{arranged in the center of the polymer cladding. Further, one or more wires may be arranged in parallel to the central pore or channel.} ^{[0055] Alternatively, a wire 104 may be transversely centered in the polymer} _{cladding 102. Further one or more pores or channels 106 may be arranged in parallel to the central wire 104.} ^{[0056] In a non-limiting example, the antenna fiber sensor ranges from 0.2 to 2 mm} _{in diameter.} ^{[0057] FIGS. 1A-1C further depicts a polymer cladding 102 with multiple pores 106 and one central core M1 of metal or conductive polymer microwire(s) 104; M2-optional} _{conductive layer Faraday cage 108; ε1-elastic cladding polymer 102 with dielectric constant} ε1 ;ε2-pore 106 filled with gas or liquid with dielectric constant ε2. D-is the fiber thickness. ^{[0058] Referring now to FIG. 1B, the principle of operation for spatial resolution is shown. An RF signal 110 with vacuum wavelength λv is coupled to the fiber-guided mode using TDR transmitter. The RF signal 110 has a step function envelope 112. In a non-limiting} _{example, the fiber mode for a single wire fiber would be a Sommerfeld-Zenneck mode. Alternatively, for a pair of parallel wires in the fiber, it will be a parallel wire transmission} Docket No. 144578.00411  ^{line mode, and so forth. The wavelength of the mode in the fiber is λf ≈ λv/√(εf), where εf is the mean-field approximation dielectric constant of the fiber, defined by ε1, ε2, and M1. Objects are applied to the fiber along its axis at points P1 and P2, creating local distortions to the εf, i.e., scattering centers. Scattering results in reflections from P1114 and P2116. In a non-limiting example, if the distance between P1 and P2 is larger than λf, two distinct} _{signals delayed by the λf/c from each other will be recorded at the RF-coupled end using TDR receiver. Alternatively, if the distance between P1 and P2 is smaller than λf, there will be no such distinction, and the reflected signals will combine into a single one. In other words, λf/c defines the longitudinal resolution for sensing the externally imposed distortions to the fiber mode.} ^{[0059] Referring to FIG.1C, the principle of operation for a proximity sensing mode is shown. In this configuration, M2 is absent, and the mode diffraction limit λf/2 is larger than} _{the fiber thickness D. In that case the evanescent field 118 of the fiber mode will have a significant component penetrating outside the fiber. An object placed within the distance} ^{λf/2 from the fiber and not touching the fiber will still create a distortion to the fiber mode, producing reflection depicted in FIG.1B. Alternatively, if λf/2 is smaller than D, then the fiber cladding has to deform by applying a stress in order to distort the fiber mode locally and create the reflection signal depicted in FIG. 1B. M2 can be added to make sure that proximity} _{signal doesn’t create any artefacts, and the measurement is purely a stress measurement, as is desired for some of the physiological monitoring applications. It should be noted that if M2 is added to the fiber while the diffraction limit is larger than the fiber thickness, no propagating mode will exist in the fiber, and fiber cannot be used as a distributed sensor either for stress or proximity.} [0060] Sensor system ^{[0061] As illustrated in FIGS. 2A-2H, an antenna fiber sensor system is disclosed that may be used to sense at least one of a pressure, temperature, proximity of an object, and location in surrounding environment at one or more points along its length. The system} _{includes at least one antenna fiber sensor, such as any of the previously described sensor configurations, and an RF generator. In a non-limiting example, the RF generator may be a TDR or a VNA.} Docket No. 144578.00411  ^{[0062] Referring to FIGS. 2A-2B, an antenna fiber sensor 200 is connected to a TDR head 204 of an oscilloscope 206 using a custom-designed 3D printed socket 202 and 50-ohm} _{connection wires to receive and transfer electromagnetic pulse, in a non-limiting example.} ^{[0063] In a non-limiting example, the socket 202 is positioned at the proximal end of the antenna fiber sensor 200 and coupled to the one or more wires within the sensor (see FIGS. 6A-B). The socket 202 contacts each of the metallic wires in the fiber to coaxial cores (the coax cables’ “signals”) for transmitting a radio frequency (RF) signal to and from the wires, while the braided jackets (the coax cables’ “grounds”) are shortened, forming a common ground. The socket 202 is further coupled to a RF generator, such as the TDR 204 or alternatively a vector network analyzer (VNA). Thus, the socket 202 provides an electrical connection between the RF generator 204 and the one or more wires of the antenna fiber sensor 200. The socket 202 may immobilize the coax-fiber interface region, through} _{equipping each separate compartment housing the fiber and each of the coaxes with gripping fins, intended to maximize mechanical stability and minimize the electrical transmission noise. In a non-limiting example, the socket may be 3D printed in biocompatible plastic, such as an autoclavable dental resin (Dental SG, Formlabs Inc.), using a stereolithography printer (Form 3B, Formlabs Inc.). Alternatively, the 3D printed socket is designed and manufactured using a CAD-CAM prototyping approach, such as 1) 3D printing and assembly of the 3D design of the socket components, or 2) injection molding of the 3D design of the socket components into 3D printed or CNC machined molds that are the negative of the socket components followed by component assembly.} ^{[0064] In one aspect, time domain reflectometry is traditionally used in the quality assessment of transmission lines over long distances. A pulse is sent along a cable and any discontinuities along the path where the submitted signal propagates is reflected to the} _{oscilloscope. Any change in impedance along the cable induces a reflection, such as the socket connecting the TDR to the fiber, changes in the dimensions of the fiber's cross- sectional geometry, reaching the end of the fiber segment, and any damage or partial rupture of the wires.} ^{[0065] In a non-limiting example the location of a deformation on the fiber is} _{considered an RC shunt, where the time delay between the incoming pulse feed and the back-} Docket No. 144578.00411  ^{reflected signal from the RC shunt resolves the location of the deformation. Voltage change} _{on the location of deformation may be measured by reflectometry as shown in FIGS. 2C-2D.} ^{[0066] TDR measurements are done by applying a sharp step voltage, for example a rise time < 7 picoseconds, through a lumped port onto a transmittance line (the fiber) and} _{measuring the reflectance (and transmittance) as function of time. The sharp step function propagates as a RF signal through the fiber, reflecting from local changes in the impedance ( ^^).} ^ ^{^^ ൌ ^^ ^ ^ ^ି ^బ ൗ ^బ ି ^ ∆^ ∆^ ା ^^ା ^బ ൌ ^^ା ^^ൗ ൌ ^^ା ^ ^^ା (1) ^ ା ^ ଶ^బା ∆^ ଶ^బ}

_{and the changed impedance. The approximation is valid for small changes.} [0067] A two-wires transmittance line is characterized by the fiber’s impedance ^^: ^{^^ ൌ ^ோା^ఠ^ ^ ^ ^^ൗ ^^ (2)}

^{conductance, inductance, and capacitance between the wires, and ^^ is the angular frequency.} _{The approximation is correct for a lossless transmittance line with highly conductive wires. For all standard line geometries (coaxial, 2-wires, and 2-plates), equation 3 is useful:} ^{^^ ൌ ^ ^^ൗ ఌ ^ ^^ ൌ ^^ ∙ ∙ ^ (3)}

^is _{a geometrical factor (1/√2 ^^ for coaxial, 1/√ ^^ for 2-wires, and 1 for 2-plates transmittance line).} ^{[0068] When an RF signal propagates through a conductor, a change in the impedance} _{cause a part of the signal to reflect relative to ΔZ/Z. The phase of the reflectance is similarly affected by the direction of ΔZ. From}

∆^ ^ ൌ െ^{∆^} ^ (4) ^{[0069] The formula of the capacitance of 2-plates wire is given in eq. 5.1, and the} _{capacitance for 2- wire transmittance line (such as the one used in this work) is given in eq. 5.2:} Docket No. 144578.00411  ^^_^^^௧^^ ൌ ^{ఌ^} ௗ (5.1) గ^ఌ ^_^

^{[0070] Applied pressures on the elastic cladding, such as by a finger or a metal weight, compresses the fiber. This compression changes the central core shape as the metal wires} _{approach each other, as illustrated in FIG. 2E. The change in the distance between the wires} ∆ ^^ changes the impedance of the fiber: ∆^ ^∆ ^ _^^^௧^^ ൌ ^ௗ ௗ (6.1)

^{in the distance between the wires. As discussed later, the electric field of the RF signal expands} _{far outside the waveguide. Therefore, a local change in the environment of the fiber changes the effective dielectric constant of the fiber. The change can be added to equation 6:} ∆^ ^_^௧^^ ൌ ^∆ௗ െ ^∆ఌ ^ _{^ ௗ ଶ∙ఌ} (7.1)

^{[0072] According to aspects of the current disclosure, the antenna fiber sensor is a multi-material fiber where the cladding, a core central channel, and the metal wires have different shapes and refractive indexes. In FIGS. 2F-2H different antenna fiber sensor embodiments are shown. FIG. 2F is a non-limiting example of an antenna fiber sensor} _{includes 75 μm copper wires aligned horizontally and embedded in SEBS cladding and a glycerol core (Cu-Gly antenna fiber sensor) doped with barium titanate (BaTiO3) to increase the dielectric coefficient by multiple orders of magnitude, since barium titanate is a common dielectric reinforcement material with a relative permittivity of 2000.} ^{[0073] FIG. 2G is a non-limiting example of an antenna fiber sensor with an air-filled} _{core and 75 μm copper wires aligned vertically and confined in SEBS cladding (Cu-Air fiber).} Docket No. 144578.00411  ^{[0074] FIG. 2H is a non-limiting example of a miniaturized fiber antenna with an air- filled core and 25 μm tungsten wires aligned vertically and confined in SEBS cladding (W-Air fiber). Integration of the fiber antenna on biomedical devices such as guidewires and catheters require microscale fiber diameter, and tungsten shows higher durability in lower} _{micron dimension. This miniaturization by the use of thinner W wires provides a theoretical downsizing towards ~100 μm cross section, significantly smaller than the ~1mm Cu-Air fiber of FIG. 2G. The fiber is drawn at a higher speed to experimentally achieve a diameter of about 400 μm.} ^{[0075] FIG. 3A (top) shows the antisymmetric mode electric field schematics in the typical fiber antenna cross section and the corresponding wiring to the RF generator through a transformer balun (bottom) allowing to invoke this mode in an exclusive manner. FIG. 3B (top) shows the symmetric mode electric field schematics in the typical fiber antenna cross section and the corresponding wiring to the RF generator while the fiber wires shortened to each other (bottom) allowing to invoke this mode in an exclusive manner. FIG. 3C shows a comparative stress sensitivity (left) and proximity sensitivity (right) of the fiber antenna operated in different modes – symmetric (referred to as “common”) antisymmetric (referred to as “transformer”), and the superposition of the two (referred to as “standard”). In the embodiments, an antenna fiber sensor system comprises an antenna fiber sensor as} _{disclosed; a radio frequency (RF) generator and receiver; and a passive or active electronic coupling the RF generator/receiver to the antenna fiber sensor. The passive or active electronic coupling the RF generator/receiver to the antenna fiber sensor provide the choice of the electromagnetic (EM) mode combination, which allows invoking the respective sensing modalities. The sensing modalities for a fiber with two wires are: a passive or active balun transformer for invoking the antisymmetric mode is connected, as in FIG. 3A, which enables exclusive sensing of stress/temperature; an impedance-matching resistor connected in series to shortened wires of the fiber, as in FIG. 3B, enabling exclusive sensing for proximity/substance identification; and an impedance-matching resistor connected in series to one of the antenna fiber wires while the other wire is grounded, making the fiber sensitive to all sensing modalities as described herein.} ^{[0076] Referring to FIG.4, an example system 400 for processing the sensed signal by} _{an antenna fiber sensor system is shown. In a non-limiting example, the system 400 may be} Docket No. 144578.00411  ^{an RF-generator, specifically a TDR or VNA. The system 400 includes an input 402, such as the reflected electromagnetic signal affected by a change in the antenna fiber sensor characteristic as a result of, but not limited to, a pressure, proximity, or temperature measurement. The system 400 further includes a processor 404. In some embodiments, the processor 404 can be any suitable hardware processor or combination of processors, such as a central processing unit (“CPU”), a graphics processing unit (“GPU”), and so on. The} _{processor 404 may communicate with a data analyzer 406 including software 408 and data 410. In a non-limiting example, the software 408 analyzes the input signal to detect changes in the originally transmitted electromagnetic signal and reflected electromagnetic signal. This detected change in the electromagnetic signal form the data 410 output from the software 408. In a non-limiting example, the processor 404 receives the data 410 and produces an output 412. The output 412 may inform about the degree, type, and location of the signal change from the input 402.} ^{[0077] As shown in the non-limiting example of FIG. 5A, antenna fiber sensors may sense a signal in two different ways: 1) through local impedance change and resulting back reflection due to pressure-induced deformation of the fiber when stress is applied (i), and 2)} _{as a result of foreign object entering the fiber’s proximity which changes the local refractive index of the fiber mode by interfering with its evanescent field penetrating outside the fiber cladding (ii), thus creating a local impedance change resulting in back reflection of a portion of the propagating RF signal.} ^{[0078] In a non-limiting example, the antenna fiber sensors may be tested in an example set-up shown in FIG.5B. In panel (i) antenna fiber sensors are stabilized using a 3D- printed fiber holder. A 3D-printed plastic pedestal is used between metal weights to analyze only the capacitance change by the deformation of the fiber by eliminating proximity. In an} _{alternative setup, the plastic pedestal is removed for proximity measurements in panel (ii). Single-point measurements are done using one metal weight on a specified location on the fiber. Additionally, multipoint measurements may also be performed by locating metal weights in multiple locations simultaneously as shown in panel (iii).} ^{[0079] In a non-limiting, demonstrated example, a Keysight DCA-X N1000A oscilloscope and N1055A, 35GHz TDR Module (Keysight, US) were used to characterize all} _{antenna fiber sensor designs. Metal wires at the beginning of 40 cm long fibers were exposed} Docket No. 144578.00411  ^{by melting and cleaving the cladding. The proximal end of the fibers connecting to the sockets were sealed by heating and pressing on them with a glass. One of the metal wires was connected to the middle of the 50-ohm connection cable, and the other was grounded. A fiber holder and weight pedestal were 3D printed from polycarbonate (PC) using Fortus 450mc FDM printer (Stratasys, USA). Fibers were straightly stabilized inside a grooved channel on the PC fiber holder. PC pedestals were used between fiber and metal weights to eliminate the proximity effect. Various metal weights were located on the fibers to measure} _{the pressure applied. The base line of the measurement is the pedestal only, and for each weight the measurement was taken as the change from the base line, divided by the amplitude of the voltage step. The measurements were smoothed using a frequency dropping of wavelength smaller than 1 cm in the signal, and a moving average with diameter of 0.5 cm. This combination does not affect the FWHM of the measurements on the pedestal, has small effect on the amplitude of the signal, and dramatically improves the SNR. Each measurement is averaged over 128 samples, taking 1-2 seconds, depending on the time scale of the measurement. Voltage resolution is <10μV.} ^{[0080] In a non-limiting example, when an electromagnetic signal propagates through the antenna fiber sensor at high frequencies, the fiber works as a waveguide. Electromagnetic simulation of the antenna fiber sensor may be performed using COMSOL Multiphysics® software to investigate its waveguide properties, for example, as illustrated in FIG. 5C. Relative permittivity and permeability of all materials, the geometry of the fiber, and the frequency of the TDR signal are defined in the simulation module. FIG. 5C shows a simulation of a 1mm antenna fiber sensor with copper wires and air-core (Cu-Air fiber) with 35 GHz signal by the reflectometer. Three guided fiber modes with different fiber refractive} _{indexes are obtained by the given parameters. As a result, an evanescence field on the basic mode of fiber, the lowest mode with the highest refractive index, is observed outside the antenna fiber sensor since the refractive index of the fiber core is lower than the refractive index of the fiber cladding as illustrated in FIG. 5C. The waveform of the propagated electromagnetic signal in the antenna fiber sensor is observed to be similar to the transverse electric wave (TE) since the electrical field was perpendicular to the waveguide. This waveguide mode provides the capability of proximity measurement to the antenna fiber sensor in addition to deformation measurement for pressure-sensing. The diffraction limit} Docket No. 144578.00411  ^{of the fiber that serves as a waveguide may be calculated to determine the minimum fiber} _{diameter, which can confine the electrical field inside using equation 8:} ^{^^ ൌ ఒ ଶ^ (8)  35}

^{the fiber is calculated at around 1.3. The diffraction limit of the antenna fiber sensor is calculated as 3.5 mm with these parameters. As a result of the diffraction limit calculation, the fiber} _{diameter should be at least 3.5 mm to confine the electrical field inside. Fiber with a 1 mm diameter, with the refractive indexes of selected core and cladding materials, is smaller than the calculated diffraction limit of 3.5 mm. Since a 3.5 mm fiber diameter is not suitable for integrating the fiber in microscale devices, core and cladding refractive indexes may be increased to confine the electrical field in the fiber to minimize the diffraction limit.} ^{[0081] FIGS. 6A-6B shows an example of the 3D printed socket and its assembly as} _{previously described.} ^{[0082] In a non-limiting example, FIGS. 7 and 8A-8C describe the modification and characterization of dielectric constant of the pores using doped glycerol with BaTiO3 nanoparticles in embodiments of the antenna fiber sensors. In an example experimental setup, the capacitance and impedance spectroscopy of 100% glycerol and a 3:1 glycerol–} _{BaTiO3 mixture was performed. 350mL volumes of each viscous liquid were measured between two immersed 25.44mm copper plates 230μm and 960μm apart in a mechanical setup designed for that purpose (Hippotronics OC-TC Oil Tester) (FIG. 7). The result of the measurements is shown in FIG, 8A-C.} ^{[0083] Referring now to FIGS. 9A-9C, results of pressure sensing by the antenna fiber sensors in terms of their sensitivity, spatial resolution, and distribution are shown, according to non-limiting aspects of the present disclosure. Electrical reflectometry analysis of pressure-sensing fibers may be performed using a 35 GHz TDR module connected to a} _{mainframe oscilloscope. In a non-limiting experimental example, a step function with 7 picoseconds rise time and 0.2V amplitude propagates through the parallel wire transmission lines of the fiber antennas while the oscilloscope monitors the voltage on the port as a function of time. The electronic setup and connection diagram schemas may be those of FIGS.} Docket No. 144578.00411  ^{2B-2C. Three fiber configurations' sensitivity and dynamic pressure range (FIGS. 9A panel (i), 9B panel (i), and 9C panel (i)) were analyzed using metal weights with different mass from 0.1 g to 100 g. A 3D-printed plastic pedestal was placed between fiber and metal weight to distinguish deformation from proximity effects that affect the effective dielectric coefficient and to allow uniform perpendicular pressure application (as shown in FIG. 5B} _{panel (i)). Measurements without the pedestal, where the weight sits or leans on top of the holder, 4 mm above the fiber, were also performed to quantify the fiber’s sensitivity to proximity effect. The pedestals used were 1 cm long and weight 0.3 g. With the pedestals, the metal weights were 5 mm above the fibers. The applied pressure of the weights on the fiber along the 1 cm of the pedestal is:} ^{^^^^^ ൌ ^^ ^^^ (9)}

_{base line of the measurement is the pedestal only, and for each weight the measurement is taken as the change from the base line, divided by the amplitude of the voltage step.} ^{[0084] In the TDR, reflection of the step function from a deformation in the fiber was measured after a time equivalent to twice the transit time of the signal to the deformation,} _{therefore the conversion between the time of the measurement and the location is given by:} ^{^^ ൌ ^௧ ଶ^^^^ (10)}

^{and ^^^^^ is the effective refractive index. Equation 10 allows for extrapolation of ^^^^^ of the} _{different fibers, using the known locations of the applied pressure and the corresponding measurements in time. Equation 10 is then used to convert the measurements from time to distance.} ^{[0085] In a non-limiting experimental example as show in FIG. 9A panel (ii), the sensitivity curve of fiber with liquid core (Cu-Gly fiber) showed a single positive slope until 40 KPa and an additional, gradually overtaking negative slope when higher pressure was} _{applied, until becomes purely negative past 80 kPa. The pressure applied by 100 gr weight negatively changes the sensitivity curve. This behavior indicates proximity affected the measurements significantly until the higher pressures. Measurements are affected significantly by deformation rather than proximity at high pressures since the sensitivity} Docket No. 144578.00411  ^{curve behaves negatively due to the horizontal metal wires in the fiber diverging by} _compression. ^{[0086] In the example above, both fiber designs with air-core (FIGS. 9B-9C) resulted in higher sensitivity since the liquid core is replaced with a more compressible air core between the metal wires located horizontally instead of vertically. The Cu-Air fiber design, showed the highest sensitivity (FIG. 9B panel (ii)). The dynamic pressure range of the} _{miniaturized fiber (W-Air fiber) is observed to be higher than the other two designs, up to 300 kPa, as shown in FIG. 9C panel (ii). The antenna fiber sensor works as a distributed pressure sensor where localized deformations by applied stress and proximity are detected with high sensitivity.} ^{[0087] Further, multipoint pressure-sensing was also performed by applying stress on multiple locations on the fiber simultaneously using metal weights with different heaviness, as illustrated by FIG. 5B panel (iii). The signal peak of the voltage change in the} _{Cu-Gly fiber design is significantly wider than the air-filled fiber designs due to the liquid core. Each measurement point on the air-filled fiber designs indicates the same ability of pressure-sensing with high sensitivity as a result of distributed sensing (FIGS. 9B panel (iii) and 9C panel (iii)).} ^{[0088] In another measurement example according to FIG.9C panel (iii), stress by the same weights on the same locations simultaneously and separately may be applied on the} _{W-Air fiber design to investigate the durability and repeatability of the fiber performance. The W-Air fiber is durable with the same sensing accuracy for repeated measurements.} ^{[0089] All three fibers showed sensitivity to unidirectional pressure 1-2 orders of magnitude higher than previously reported result13 for distributed sensing. The Cu-Gly fiber showed an initial signal in the same direction as the other two, even though the different orientation of the wires is predicted to generate a signal of opposite direction. However, the sensitivity shows transition between two clear regions, indicated in FIG. 9A panel (ii)^by the} _{dotted lines. The first region, a rapid increase in the signal with small weights, is believed to indicate a small in the effective dielectric constant of the fiber due to realignment and movement of the fiber relative to the holder and the pedestal, eliminating or reducing air pockets around the fiber. This effect is amplified by the coarse surfaces of the 3D printed elements. The second region, a slower change in the signal at higher pressures, is believed to} Docket No. 144578.00411  ^{be the actual deformation of the air gap. This is corroborated by the linear increase in the signal at high pressures for the air-gapped fibers (Cu-Air and W-Air), indicating an increase in capacitance, while the signal decreases in high pressures for the Cu-Gly fibers, corresponding to decrease in capacitance. This behavior is expected for the Δd, generated by the applied pressure. When high pressure was applied (by finger, above 1 Kg, not shown} _{here), the signal for Cu-Gly changed direction, while the signal for the air gaped fiber increased without changing direction, further supporting the assumption that the high- pressure slope is due to deformation. The slopes, maximum sensitivity and impedance of the various fiber are summarized in Table 1. TABLE 1: Sensitivity and Impedance of the fibers}

ⁱⁿ _{impedance within the measured range for all three fibers.} ^{[0091] In FIG. 10A, the fibers according to aspects of the current disclosure show higher sensitivity than the pressure sensors on the market by a significant voltage difference obtained with lower applied stress. The fibers according to aspects of the current disclosure are characterized by below 0.1Kpa sensitivity since 0.1 g weight with 1 mm width located on} _{1 mm fiber diameter corresponds to 0.1 kPa. Since the signal-to-noise ratio of the signal obtained by 0.1 g applied stress is low, the example antenna fiber sensors presented in the current disclosure are highly capable of measuring pressure lower than 0.1 KPa (FIG. 10A).} ^{[0092] The accuracy of measuring impedance by signal reflectance drops with the impedance squared. Assuming a small change in the impedance in the measurements, the} _{sensitivity of the voltage measurement by the oscilloscope is limited by (from equation 1):} Docket No. 144578.00411  C^u-

w^{e can, 11,} _{expect Cu-Air to be 6 times more sensitive than W-Air due to lower impedance. As shown, it is about 7 times more sensitive. There may be signal loss due to the high mismatch in the fiber coupling.} ^{[0094] As conveyed above, deformation measurements are isolated from proximity to distinguish the effect of applied stress as the pressure-sensing mechanism. Since the fiber sensors according to aspects of the current disclosure are capable of both deformation and proximity measurements, proximity and deformation are isolated by using metal weights 4 mm away on the fiber sensor without using the plastic pedestal in between in the following} _{analysis, as shown in FIG.10B. In an example measurement, 2 g, 20 g, and 200 g weights (6.98mm, 14.93 mm, and 24.93 mm width) are located 4 mm away from the miniaturized W- Air fiber. Since the weights' width increases proportionally with their heaviness, the highest voltage change occurs by applying 200 g with 24.93mm width (Figure 10B). This proximity sensing by the fiber sensors described herein may be useful in many application fields, such as touch board screens and cyber-physical interfaces.} ^{[0095] Strong dispersion limits the overall fiber length, which is functional for pressure-sensing applications. In a non-limiting example, the FWHM of the signals from the 1 cm pedestal was measured for the fibers at different locations for a constant weight (FIGS. 11A-11C). To overcome the broadening of the signal width due to dispersion when an electromagnetic signal propagates through the fiber, the TDR according to aspects of the current disclosure resolves space to the frequency and analyzes the fiber's spatial resolution,} _{indicating the closest possible distance between two measurement locations and overall functional fiber length. In a non-limiting example, a 50 cm fiber length is durable for pressure-sensing since the measurements at the end location of the fiber are still in a sensible spatial resolution range. The spatial resolution for the Cu-Gly fiber, Cu-Air fiber, and W-Air fiber are illustrated in FIGS. 11A-11C. Cu-Air antenna fiber sensors display a high spatial resolution and low dispersion with a FWHM of 1.15 cm at 6 cm and 1.4 cm at 46 cm. W-Air} Docket No. 144578.00411  ^{antenna fiber sensors displayed a higher dispersion with FWHM of 1.2 cm at 6 cm and 2.7 cm at 46 cm, indicating dependence of the dispersion on the geometry of the fiber. Cu-Gly antenna fiber sensors displayed a high FWHM or 4-6.5 cm, possibly due to high dispersion} _{for dispersion of high frequency signal in the glycerol-BaTiO3 solution. Fiber designs with air cores result in a high spatial resolution of 1 cm, which is ideal for a distributed sensor (FIGS. 11B-11C).} ^{[0096] Multimaterial, functional fiber pressure sensors are ideal alternatives for microsystems to commercial pressure sensors due to their minimized dimensions,} _{preserved functionality, and easy integration with any device. As such, functionality in a fluidic environment is crucial for measurements such as blood pressure in the vascular system.} ^{[0097] In a non-limiting example, the functionality of the fibers according to aspects of the present disclosure are characterized in a fluidic environment to measure the hydrostatic pressure by levels of a fluid column. Referring to a measurement setup in FIG. 12A, water is filled in a closed graduate cylinder system where the pressure-sensing fiber} _{(Cu-Air) is stabilized to measure hydrostatic pressure with respect to heights (FIG. 12B). Output voltage drastically decreases on the water-air interface at all heights. Measurements at 40cm, 50cm, and 55cm on fiber were linearly analyzed with sensitivity of 0.4 mV/kPa. (FIG. 12C).} ^{[0098] In a demonstrated example, long fibers were sealed on the bottom, and both metal wires were exposed on top to connect with the TDR module. The hydrostatic pressure of the water was measured with a setup that includes a 50 cm-long sealed and leakproof glass cylinder. A glass rod was located in the middle of the cylinder to immobilize the fiber during measurements. The fiber was glued on the center of the glass rod fixed on the top cover of the glass graduated cylinder. The top cover has an embedded SMA connector to} _{enable fiber and TDR module connection. This connection was designed specially to protect the connection from the liquids. The glass graduate cylinder has five outlets on the front side for insertion of a pressure transducer to compare TDR results with transducer values. Due to the known hydrostatic pressure data from the literature, deionized water was chosen as sample liquids. The graduated cylinder was filled with liquid until each of the five} Docket No. 144578.00411  ^{measurement points was submerged, and measurements were taken at each location with} _{both TDR and the pressure transducer.} ^{[0099] The antenna fiber sensors disclosed herein display two orders of magnitude higher pressure sensitivity than previously reported for distributed sensing. The high results are likely due to change of the dielectric coefficient of the environment of the fiber. Even} _{considering only the pressure sensitivity of the fibers, Cu-Air displays sensitivity an order of magnitude higher than any previously reported, with high spatial resolution and low dispersion. This is the first reported distributed system with the potential to measure hydrostatic pressure.} ^{[0100] In a non-limiting example, the antenna fiber sensor may also sense temperature differences along the length of the sensor. The thermal differential expansion of the cladding affects the wire separation, in turn affecting the field distribution of the antisymmetric mode. The local sensing of the temperature, similar to stress sensing, results from the RF reflection from the temperature-deformed location of the antenna fiber due to the mode mismatch at this location when compared to the rest of the fiber. The dielectric coefficient of the material of the fiber can also change as function of temperature. The aforementioned changes in separation and dielectric properties will change the impedance of the fiber and can be measured using the previously mentioned procedures. The fiber can be doped with nano or microparticle with high temperature dependent dielectric properties, ,such as SrTiO3 or BaTiO3, in order to increase the thermal sensitivity . As shown in FIGS.} _{13A-13C fiber antenna can serve as a multipoint temperature sensor with ~1cm resolution and sub-1 deg. sensitivity. In FIG.13A two fibers, hollow core and Cu-Gly core are shown side by side with heating elements 1 cm wide arranged at two locations below the fibers, contacting them thermally, in a group of three at 11-14 cm from the fiber sockets, and a single element at 22-23 cm from the fiber sockets. FIG.13B and 13C (top) demonstrate Cu-Gly core fiber and hollow core fiber response V/V0 [a.u.], respectively, to the heat resulting from the voltage of 2v (blue line), 4v (orange line), 6v (yellow line), 8v (purple line), and 10v (green line) applied to the resistive heating elements, as function of location along the fibers measured in centimeters, overlayed against the heat map collected by the thermal camera. The fibers are painted black to prevent the thermal emissivity noise in the thermal camera readings. The table provides the calibration of the peak V/V0 values in FIG.13B and 13C (top)} Docket No. 144578.00411  ^{to the respective peak temperatures collected by the thermal camera in FIG. 13B and 13C} _(bottom). ^{[0101] In a non-limiting example, the effects of temperature may be detected in a} _{region of inflammation in a tissue or organ.} ^{[0102] In a non-limiting example, the RF generator generates an electromagnetic signal which is transmitted to the one or more wires of the antenna fiber sensor. The electromagnetic signal is reflected back to the RF generator upon reaching the distal end of the sensor or due to some change in the characteristic of the fiber sensor. For example, the} _{change in characteristic includes, but is not limited to, a change in the impedance of the electromagnetic signal due to a change in the dielectric constant of the antenna fiber sensor. In a non-limiting example, the dielectric constant may be affected by, but not limited to, a pressure, temperature, proximity of an object, or dielectric constant of the surrounding environment.} ^{[0103] In a non-limiting example, pressure may include hydrostatic pressure or dynamic pressure. Alternatively, the pressure may include a stress causing a deformation at one or more locations along the length of polymer cladding. For example, a deformation in the antenna fiber sensor inserted into a vessel of a subject may be caused by, but not limited to, a blood pressure, a change in blood pressure, a curvature of a vessel, and an obstruction} _{of a vessel. In another example, deformation in the antenna fiber sensor inserted into a urinary tract of a subject may be caused by, but not limited to a pressure in the urinary tract, a change of pressure in the urinary tract, a stricture of the urinary tract, and obstruction of the urinary tract. In another example, the deformation is caused by at least one of a pressure or change in pressure in a pleural cavity, abdominal cavity, or digestive tract.} ^{[0104] In a non-limiting example, the parameter of the surrounding environment may include pH. pH sensing occurs when the antenna wires are exposed to the environment through the cladding pores, and a reference material, standard to the pH sensors, is present} _{as an additional core spanning the fiber length. Local changes in pH will be expressed as a local change in the wire's affinity to the electric potential, directly expressed in the local change in response to RF signal propagation. ^} ^{[0105] According to the present disclosure, a method for sensing, for example within} _{a vessel or body lumen, using an antenna fiber system is described. As shown in FIG. 14, the} Docket No. 144578.00411  ^{antenna fiber system may include the system and sensors described above. The method 1400 includes inserting the antenna fiber sensor into a vessel at step 1402. Thereafter, an electromagnetic signal is transmitted from the RF generator at step 1404. At step 1406, the reflected electromagnetic signal is received. The reflected signal is analyzed to detect} _{impedance changesat step 1408. The change in impedance may occur as a result of, but not limited to, a stress applied to the antenna fiber sensor, an object in proximity to the antenna fiber sensor, or a temperature difference. At step 1410, impedance changes are converted into a change in the characteristic of the sensor. At step 1412, the location of the change in characteristic along the antenna fiber sensor is detected.} ^{[0106] According to the present disclosure, a method of making an antenna fiber sensor is described. The antenna fiber may include the sensors described above. The method includes the steps of: producing a polymer cladding preform including one or more channels} _{and one or more passages, and thermally drawing the polymer cladding preform with one or more wires feeding into the one or more passages. In embodiments, the polymer cladding is a composite of a thermoplastic elastomer and a dielectric-constant modifying filler.} ^{[0107] Referring to FIG. 15, the antenna fiber sensors may be fabricated using VLSI- Fi (Very large-scale integration on fibers), a technique that combines VLSI phenomena with the thermal drawing technique for fiber devices. The VLSI-Fi involves the thermal drawing of macroscale 3D printed preforms into microscale fiber devices. VLSI-Fi is a three-step process where a rod, typically a cylinder or parallelogram, called a preform, is 3D printed.} _{The preform consists of a cladding made of a material chosen for its structural properties that house a core structure composed of dissimilar materials typically chosen to provide a function to the fiber device. The assembled preform, often going through additional consolidation to confine all material tightly together, is then placed in an upright format to soften and pull down like taffy into a fiber. During this second step, the cross-section is preserved and scaled-down orders of magnitude smaller.} ^{[0108] As will be described in further detail below, the drawn fiber can go through thermal treatments to change the material properties and break up the gas or liquid-filled} _{hollow core into periodic spheres by enhancing interfacial stress between core materials. For example, the central core channel has periodic breakups of doped glycerol with BaTiO3.} Docket No. 144578.00411  ^{[0109] In a non-limiting example, preforms are shaped by consolidating superimposed, transparent SEBS sheets. A convergence method is used to introduce metal wires to the preform by a custom design 3D printed head where two metal wires on spools are stabilized in parallel and freely unspooled by fiber pulling. The preform is heated above the glass transition temperature of polymer cladding inside a furnace and pulled with a particular draw speed and tension by a capstan while its cross-section is preserved (FIG} _{15A). For the Cu-Gly fiber, a syringe injects preheated glycerol doped with BaTiO3. into the core channel without applying pressure, since a pressurized injection may result in a rounded core shape (FIG. 15B panel (i)). The doped glycerol is removed to draw a hollow core in the Cu-Air fiber and W-Air fiber designs. The hollow cores are elongated for easier deformation under perpendicular pressure (FIG. 15B panel (ii) and 15B panel (iii)) while minimizing the distance between the wires.} ^{[0110] In one non-limiting example, 14cm long preforms are drawn into over 100m of fibers and spooled (FIG. 15C panels (i)-(iii)). The sensing properties of the fibers are then tested using time-domain reflectometry analysis. According to this example, the segments of the Cu-Gly fiber used for measurements have a width of 670±40μm, a height of 320±20 μm, a distance between the center of wires of 350±30 μm, and a diameter of glycerol gap of 170±20 μm. Air pockets are visible around the wires. The segments of the Cu-Air fiber used} _{for measurements have a width of 950±20 μm, a height of 440±20 μm at the side, and a curving height of 540±20 μm at the center. The copper wires are 290±10 μm from each other with a 125±20 μm air gap. The segments of the W-Air fiber used for measurements have a width of 430±20 μm, a height of 205±10 μm at the side, a curving height of 270±10 μm at the center. The copper wires are 200±20 μm from each other with a 100±10 μm air gap. The dimensions of W-Air and Cu-Air were chosen to have similar sensitivity according to equation 6.2.} ^{[0111] In a non-limiting example, a procedure for modifying the dielectric constant of the cladding is shown in FIG. 16, wherein nanofillers are premixed into the cladding elastomer. The pellets of SEBS are dissolved in toluene, and a 1:2 of BaTiO3 nanoparticles to} _{SEBS by weight is mixed into the resulting liquid, while stirring. Then the mixture is poured into a flat tray, and the toluene is evaporated, leaving a composite SEBS:BaTiO3 sheet, that is then used for preform fabrication as above.} Docket No. 144578.00411  ^{[0112] Referring now to FIG.17, a non-limiting example of the preparation of BaTiO3- doped glycerol for filling the core(s) or pore(s) is shown. In this experimental example, biocompatible glycerol mineral oil (Sigma Aldrich, G5516) is mixed at a 1:3 and 1:9 w/w} _{ratio with barium titanate 100nm-sized nanopowder (SSNano, 1401GC) at room temperature while stirred magnetically at 400 rpm. In a non-limiting example, this dielectric liquid may be heated and stirred during a drawing process to fill a core or preform core as described in further detail below.} ^{[0113] In a non-liming example of forming the antenna fiber sensor, SEBS was used for a cladding preform. SEBS pellets (Kraton, US G1657, elastic properties as 23 MPa tensile strength, and %750 elongation break) as shown in FIG. 18 (left) were evenly spread on a metal sheet and surrounded by PTFE bars (McMaster-Carr, U.S.) on all edges to create 1- 2mm thick transparent SEBS sheets. SEBS pellets on the metal sheet were first melted in a vacuum oven at 180-200°C, preferably 175oC for 2-4 hours to merge the pellets. Polymer pellets were dispersed in between two steel plates uniformly and Teflon sheets and bars} _{were used to set the thickness of the sheets and to prevent the pellets from sticking to the steel plates sticking on them, as shown in FIG. 18. After the PTFE bars are removed, metal weights are put on top of the pellets covered with PTFE film (McMaster-Carr, US) to create a thin SEBS sheet. The sheet was relocated into the vacuum furnace for 4-6 more hours. PTFE films were needed on both top and bottom of the pellet sheet to prevent sticking on the surface and for easy removal afterward. A transparent SEBS sheet was obtained 4 hours later. The thickness of the sheets is typically 2-3mm (FIG. 18, right).} ^{[0114] In a non-limiting example of the method for forming antenna fiber sensors, prepared SEBS sheets were cut into rectangular layers to create the preform geometry. The sheet was cut in multiple slabs to assemble the multilayer preform construct as shown in FIG.19. Steel plates were aligned with Teflon spacers along the preform to provide pressure on the multilayer preform to push layer-by-layer merging while the polymer is softened} _{under heat. For internal channels in the preform, Teflon slabs are used to preserve their geometry during the consolidation process. The TPE sheets are cut and stacked to form a structure that has hollow cores for the incorporation of wires and to form pores, hollow or filled with liquid later in the drawing process. The outer dimensions of the preform for fibers with air gap are 15 mm to 30 mm, 14cm long. The dimensions of the inner channels were 1-} Docket No. 144578.00411  ^{2mm for wire channels and 2mm to 10mm for the central air gap channel. The outer dimensions of the preform for the fiber with liquid core are 25mm to 33mm, 14cm long. The dimensions of the inner channels are 3-4mm for wire channels and 2mm for the central} _{liquid channel. The multilayer structure is vertically oriented, similar to a sandwich, and consolidated in a vacuum oven at 1750C to 180°C for 2 hours using a lightweight on top to merge all layers. FIGS. 19 and 20A-10B show preforms before and after the consolidation.} ^{[0115] In a non-limiting example as shown in FIG. 21A, a 3D printing setup is shown for forming the antenna fiber sensor preform as an alternative or in addition to method described immediately above. For example, Fused Deposition Modeling (FDM) method of 3D printing was used to create dimensionally accurate and consistent preforms for the sensing fiber. The 3D printer body is a LulzBot Taz with a SKR pro v1.2 mainboard and runs with custom Marlin firmware. A Mahor XYZ v4 Pellet Extruder with a 0.8mm nozzle was used to replace the standard filament extruder in order to print SEBS. A textured Overture Build Surface was placed on the print bed to increase adhesion. Preform 3D files were sliced and} _{converted to G-code using Ultimaker Cura. The print settings were adjusted as needed using Pronterface. Models were sliced in Cura with the following key settings: Nozzle temperature 235°C, build plate temperature 50°C, layer height 0.32 mm, wall line count 1, top/bottom layers 0, infill density 100%, infill pattern lines, print speed 25 mm/s, first layer speed 10 mm/s, retraction off, print cooling off, print flow 150%. The G-code was then run on the printer through Pronterface, where the flow was further increased by 175%. SEBS pellets were loaded into the extruder in small portions to prevent overheating within the extruder. The models were then printed, resulting in the infill being free of voids. FIG. 21B shows the samples of 3D printed preform structures.} ^{[0116] In a non-limiting example, the thermal draw is performed by a procedure similar to the fabrication of an optical fiber. A preform is dropped slowly into the tube furnace at an elevated temperature until it becomes a viscous liquid and drips down, carrying a thin thread. That thread is grabbed onto at the bottom of the furnace by a tractor and} _{spooled. Driven by volume conservation, the scale down in fiber cross-section compared to that of the preform is defined by the ratio between the fiber draw speed by the spooler (typically meters or tens of meters per minute) and the preform feed speed into the furnace (typically millimeters per minute). FIGS. 22A-22D and FIGS. 23A-23D show the typical} Docket No. 144578.00411  ^{preform arrangement before and after the draw and the different stages of the draw itself, specifically for the case of fiber antenna device, where the wires are incorporated by confinement of the preform cladding around the wire, attached to the bait off, and thus} _{spooled down into the fiber at the draw speed rate. The hole in the preform accommodating the wire is initially wider than the wire, and reduces in size to confine tight around it in the draw cone, as the cladding cross-section is scaled down.} ^{[0117] In a non-limiting example of making an antenna fiber sensor with a liquid core (Cu-Gly antenna fiber sensors), the prepared SEBS preform is fixed to a hollow handle through which two 75μm copper wires (Goodfellow, US, CU00-WR-000120) sitting on near- frictionless spools are fed through the hollow side core channels of the preform. The setup is introduced into the vertical furnace with three zones of heat of a drawing tower (Optogear, Finland). A wire at the bottom end of the preform is fixed with a weight of 5g to initiate} _{tension in the draw as the drawing cone forms as the preform begins to soften in the furnace. The preform with liquid core and copper wires is thermally drawn at the set temperatures of zone 1 (top), 2 (middle), and 3 (bottom) were 120°C, 250°C, and 135°C at heating, 180°C, 270°C, and 195°C at startup, and 180°C, 270°C, and 195°C at the draw settings. The fiber is drawn with 0.40mm/min feed speed and 4m/min draw speed. The target fiber diameter is set up to 250 microns.} ^{[0118] In a non-limiting example of making an antenna fiber sensor with an air core (Cu-Air and W-Air antenna fiber sensors), the preform is vertically fixated to the preform holder PTFE rod, where two 75-micron copper wires (GoodFellow, US, CU00-WR-000120) or two 25-micron tungsten wires (GoodFellow, US, W-00-WR-000130) are aligned on top using a custom-design wire feeding mechanism (suture fiber ref.). Metal wires are carefully} _{fed inside the side channels and loosely fixated on the metal wire on the bottom, which holds a 5g weight to pull the bait off. The preform with air gap and tungsten wires are thermally drawn at the set temperatures of zones 1, 2, and 3 were 120°C, 250°C, and 135°C at heating, 180°C, 270°C, and 195°C at startup, and 180°C, 270°C, and 195°C at the draw settings. The fiber is drawn with 0.40 mm/min feed speed and 4m/min draw speed. The target fiber diameter is set up to 180 microns.} ^{[0119] In a non-limiting example, a liquid, such as undoped glycerol or BaTiO3-doped} _{glycerol as previously described may be incorporated into the hollow core of preform during} Docket No. 144578.00411  ^{thermal drawing. In FIG. 24A, the liquid may be manually injected using a syringe. Alternatively, in FIG. 24B, the liquid may be incorporated via suction during drawing from an open syringe. The setup of FIG.24B, wherein the open syringe hanging about the preform, in which we fill its content with new doped glycerol mixed and heated at 200°C, is effective} _{for flowing the liquid into the hollow core during the draw. The fiber draw creates negative pressure in the hollow core, resulting in a natural suction from the syringe, which output is hermetically sealed to the hollow channel on the top of the preform. This approach addresses the potential challenge of controlling pressurization during the draw relative to the manual injection approach.} ^{[0120] In a non-limiting example, an automated syringe injector may be used to fill liquid into the core if the flow rate is controllable to set a continuous flow, and suitable with} _{metal syringe usage in order to maintain the liquid temperature high enough which is needed to stabilize the viscosity of the liquid for easy flow and preform temperature for continuous drawing.} ^{[0121] In a non-limiting example, FIGS. 25A-25B show typical data of the drawing} _{parameters of liquid glycerol in SEBS.} ^{[0122] In a non-limiting example, the antenna fiber sensor may undergo post- processing, such as to form discrete liquid or gas-filled pores as is described with reference to FIGS. 26A-26B. For example, a fiber with a repeating 2 cm collapsed section and 2 cm un-} _{collapsed section was created. This was done by heating the fiber and applying periodic pressure for several minutes on the hot plate (FIGS. 26A-26B). Collapsing or reheating the fiber to initiate a capillary breakup of the hollow or liquid filled core can be used to create discontinuity in the hollow cores, forming closed pores.} ^{[0123] In a non-limiting example, the core may be broken up into an array of spheres along its axis as a result of the tension between two viscous liquids facing each other. In order} _{to reduce the interfacial tension between the two materials, they naturally adopt the configuration that decreases their interacting surface area, as illustrated in FIG. 27. Experimentally, FIG. 28 shows the evolution of a core breaking up.} ^{[0124] A more optimized breakup was conducted using an automated tapering setup20 and multiple runs were done to achieve the desired breakup. FIG.29A illustrates this} _{setup. This stage of the fabrication process is still being optimized. FIG. 29B show the level} Docket No. 144578.00411  ^{of progress, where a wavy pattern is observable but not yet a full breakup in the time range expected. In an example procedure, preliminary results using uniform heating on a hot plate} _{were achieved for glycerol-doped SEBS core as shown in FIG. 29C. The breakup takes place around 205°C-215°C.} ^{[0125] Breaking up a continuous core into isolated gas or liquid-filled sections provides regions along the antenna fiber sensors’ length that are more sensitive to a} _{stimulus. This embodiment results in improved signal to noise ration without affecting the spatial resolution, assuming the distance between discrete gas or liquid-filled sections is smaller than the spatial resolution defined by the TDR bandwidth.} ^{[0126] In a non-limiting example, the method further includes forming a preform with a plurality of planar sheets of the thermoplastic elastomer polymer or the composite of a thermoplastic elastomer and a dielectric-constant modifying filler, the planar sheets being equal dimensions; stacking the plurality of planar sheets by their largest surface area such} _{that each outer edge of each planar sheet of the plurality of planar sheets align; and heating the plurality of stacked planar sheets to consolidate the perform. In embodiments, in forming the plurality of planar sheets, a length of each planar sheet in is larger than its width. (see, FIGS. 19 to 24).} ^{[0127] In a non-limiting example, a large planar sheet of the polymer or composite is cut to form the plurality of planar sheets of polymer or composite of equal dimensions.} _{Further, one or more channels and one or more passages are cut along the of the stack of the plurality of planar sheets using molds configured for forming one or more pores and enclosing one or more wires, respectively. (see, FIG. 18)} ^{[0128] Alternatively, each planar sheet is three-dimensionally (3D) printed. For example, each planar sheet may be 3D printed and then stacked as previously described, or each 3D printed planar sheet is 3D printed on top of another 3D printed planar sheet. In a non-limiting example, the one or more channels and one or more passages may be cut along} _{the length of the stack of the plurality of planar sheets using molds as described above. Alternatively, openings for each of the one or more channels and one or more passages are printed in each of the planar sheets to form the one or more channels and one or more passages when the plurality of planar sheets are stacked. (see, FIGs. 21A-21B).} Docket No. 144578.00411  ^{[0129] In a non-limiting example, the polymer and dielectric-constant modifying filler} _{are mixed in solution before forming each of the plurality of planar sheets.} ^{[0130] In a non-limiting example, thermally drawing the polymer cladding preform includes: inserting the polymer cladding preform in a preform holder; inserting the one or more wires into the one or more passages; feeding the polymer cladding preform and one or} _{more wires into a heater until a bait-off drops off the polymer cladding preform forming a tapering region and a starting end of the antenna fiber sensor; and grabbing the starting end of the antenna fiber sensor and wrapping it around a capstan and spooling it onto a spool. (see, FIG. 22 and 23).} ^{[0131] In a non-limiting example, the liquid is heated and injected into the one or more channels during the thermal drawing of the polymer cladding preform. The liquid may} _{be manually injected during the thermal drawing. Alternatively, the liquid may be injected by suction force during the thermal drawing of the polymer cladding preform. (FIG. 24)} ^{[0132] In a non-limiting example, the thermal drawing is performed by first heating the polymer cladding preform and wires and optional filling. A thermal drawing furnace may have distinct temperature zones (e.g., top, middle, bottom). In a non-limiting example, the top, middle, and bottom temperatures may be 120°C, 250°C, and 135°C, respectively. At the start-up of the thermal drawing, the top, middle, and bottom zones of the furnace may be} _{increased to 180°C, 270°C, and 195°C, respectively. In a non-limiting example, the draw may proceed at the start-up temperature. In a non-limiting example, the fiber is drawn with a 0.40 mm/min feed speed and a 4 m/min draw speed. Alternatively, the temperatures and feed and draw speeds may be adjusted based on the polymer cladding preform composite materials and desired fiber diameter.} ^{[0133] In this description, it will be readily apparent to one skilled in the art that varying substitutions and modifications may be made to the invention disclosed herein without departing from the scope and spirit of the invention. The invention illustratively described suitably may be practiced in the absence of any element or elements, limitation or} _{limitations which is not specifically disclosed herein. The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention that in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various} Docket No. 144578.00411  ^{modifications are possible within the scope of the invention. Thus, it should be understood that although the present invention has been illustrated by specific embodiments and} _{optional features, modification and/or variation of the concepts herein disclosed may be resorted to by those skilled in the art, and that such modifications and variations are considered to be within the scope of this invention.} ^{[0134] Citations to a number of non-patent references are made throughout this disclosure. The cited references are incorporated by reference in their entireties. In the event} _{that there is an inconsistency between a definition of a term in this specification as compared to a definition of the term in a cited reference, the term should be interpreted based on the definition in the specification.} ^{[0135] References} _{1. Wang, C., Wang, C., Huang, Z. & Xu, S. Materials and Structures toward Soft Electronics.} ^{Adv.^Mater.^30, 1801368 (2018). 2. Yin, L. et^al.^A stretchable epidermal sweat sensing platform with an integrated printed battery and electrochromic display. Nat.^Electron.^5, 694–705 (2022). 3. Wang, X., Gu, Y., Xiong, Z., Cui, Z. & Zhang, T. Silk-molded flexible, ultrasensitive, and highly stable electronic skin for monitoring human physiological signals. Adv.^Mater.^26, 1336–1342 (2014). 4. Leber, A. et^al.^Soft and stretchable liquid metal transmission lines as distributed probes of multimodal deformations. Nat.^Electron.^3, 316–326 (2020). 5. Yu, L. et^al.^Flexible Multi-Material Fibers for Distributed Pressure and Temperature} _{Sensing. Adv.^Funct.^Mater.^30, 1908915 (2020). 6. Pozar, D. M. Microwave^Engineering,^4th^Edition. (Wiley, 2011). 7. Liu, Z., Wu, H., Ren, W. & Ye Molecular Sciences and Chemical Engineering, Z.-G. B. T.-R. M. in C. Piezoelectric and ferroelectric materials: Fundamentals, recent progress, and applications. in (Elsevier, 2022). doi:https://doi.org/10.1016/B978-0-12-823144- 9.00069-8. 8. Anderson, G. P. & Taitt, C. R. Chapter 2 - EVANESCENT WAVE FIBER OPTIC BIOSENSORS. in (eds. Ligler, F. S. & Taitt, C. R. B. T.-O. B. (Second E.) 83–138 (Elsevier, 2008). doi:https://doi.org/10.1016/B978-044453125-4.50004-8.} Docket No. 144578.00411  9. Faccini de Lima, C. et^al.^Towards Digital Manufacturing of Smart Multimaterial Fibers. ^{Nanoscale^Res.^Lett.^14, 1–16 (2019). 10. US20210333131A1 Gumennik et al.}   _{11. van der Elst, L. et^al.^3D Printing in Fiber-Device Technology. Adv.^Fiber^Mater.^2021^32^} ^{3, 59–75 (2021). 12. van der Elst, L. A. et al. Microstructured Electroceutical Fiber-Device for Inhibition of Bacterial Proliferation in Wounds. Adv Mater Interfaces 2201854 (2022) doi:10.1002/ADMI.202201854. 13. US20220401616A1 Sen et al. 14. Nakata, S., Shiomi, M., Fujita, Y., Arie, T., Akita, S., & Takei, K. (2018). A wearable pH} _{sensor with high sensitivity based on a flexible charge-coupled device. *Nature Electronics*, 1, 596-603. https://doi.org/10.1038/s41928-018-0152-6 15. Wencel, D., Abel, T., & McDonagh, C. (2014). Optical Chemical pH Sensors. Anal. Chem., 86(1), 15-29. https://doi.org/10.1021/ac4035168 16. Paschew, G., Klatt, S., Lienig, J., Arndt, K.-F., & Adler, H.-J. P. (2008). Sensors 2008, 8(1), 561-581. https://doi.org/10.3390/s8010561}

Claims

Docket No. 144578.00411  C^{LAIMS^ We claim: 1. An antenna fiber sensor comprising: a polymer cladding with an outer surface, a length extending between a proximal end and a distal end along a first axis, a width, and a thickness, wherein the polymer cladding is a composite of a thermoplastic elastomer and a dielectric-constant modifying filler; one or more pores surrounded by the polymer cladding and distributed between the proximal end and the distal end of the cladding, wherein the one or more pores has a diameter less than the width and thickness of the polymer cladding; and one or more wires extending within the polymer cladding and between the proximal end and distal end of the cladding. 2. The antenna fiber sensor of claim 1, wherein the polymer cladding has a width in a} r_{ange of about 200 µm to 2 mm. 3. The antenna fiber sensor of claim 1, wherein the polymer cladding has a thickness, and the one or more pores and one or more wires are contained within the cladding thickness. 4. The antenna fiber sensor of claim 1, wherein the one or more pores are located parallel to the one or more wires. 5. The antenna fiber sensor of claim 1, wherein the one or more pores are channels extending through the polymer cladding from the proximal end to the distal end of the polymer cladding. 6. The antenna fiber sensor of claim 1, wherein the polymer cladding has one pore and the one pore is located about a center of the polymer cladding.} Docket No. 144578.00411  ^{7. The antenna fiber sensor of claim 6, wherein the one or more wires is located parallel to the pore in the center of the polymer cladding. 8. The antenna fiber sensor of claim 1, wherein the one or more wires is located about the center of the polymer cladding. 9. The antenna fiber sensor of claim 1, wherein the thermoplastic elastomer is selected from the group consisting of styrene-ethylene-butylene-styrene (SEBS), cyclic olefin copolymer (COC), elastomeric cyclic olefin copolymer (ECOC), polysulfone (PSU), poly(methyl methacrylate) (PMMA), polycarbonate (PC), polyvinylidene fluoride (PVDF), polyetherimide (PEI), and polydimethylsiloxane (PDMS). 10. The antenna fiber sensor of claim 1, wherein the dielectric-constant modifying filler is selected from ferroelectric oxides including barium titanate (BaTiO3) and} s_{trontium titanate (SrTiO3), metal and transition metal oxides including Calcium copper titanate (CaCu3Ti4O12), La2−xSrxNiO4, and derivates thereof, intrinsic or doped semicondutors including silicon (Si), germanium (Ge), and gallium antimonide (GaSb), and conductors including silver (Ag) and carbon (C). 11. The antenna fiber sensor of claim 10, wherein the amount of dielectric-constant modifying filler in the polymer cladding ranges from more than 0% to about 50% by volume that allows tuning a mean field dielectric constant εf. 12. The antenna fiber sensor of claim 11, wherein the dielectric-constant modifying filler has particles in a size range of 10 nm – 500 nm. 13. The antenna fiber sensor of any one of claims 1-12, wherein the sensor is flexible, compressible, or both. 14. The antenna fiber sensor of claim 1, wherein the one or more pores are filled or hollow.} Docket No. 144578.00411  ^{15. The antenna fiber sensor of claim 14, wherein the one or more pores are completely filled or partially filled. 16. The antenna fiber sensor of claims 14 or 15, wherein the one or more pores are filled with a gas or a liquid. 17. The antenna fiber sensor of any one of claims 14 to 16, wherein the one or more pores are filled with air, glycerol, or a colloidal liquid. 18. The antenna fiber sensor of any one of claims 14 to 17, wherein the one or more pores are filled with a colloidal liquid including glycerol or polyethylene glycol doped with a high dielectric constant filler. 19. The antenna fiber sensor of claim 18, wherein the high dielectric constant filler is BaTiO3 or SrTiO3.} _{20. The antenna fiber sensor of claim 1, wherein the one or more pores has a dielectric constant ε2. 21. The antenna fiber sensor of claim 1, wherein the one or more wires are a metal or conductive polymer composite. 22. The antenna fiber sensor of claim 21, wherein the metal is copper (Cu), zinc (Zn), silver (Ag), or tungsten (W). 23. The antenna fiber sensor of claim 21, wherein the conductive polymer composite is carbon black-doped polycarbonate (CPC), carbon black-doped polyvinylidene fluoride (PVDF), carbon black-doped polyetherimide (PEI), carbon nanotube-doped CPC, carbon nanotube-doped PVDF, carbon nanotube-doped PEI, or combinations thereof.} Docket No. 144578.00411  2^{4. The antenna fiber sensor of any one of claims 1-23, further comprising a socket positioned at the proximal end of the polymer cladding and coupled to one or more wires. 25. The antenna fiber sensor of claim 24, wherein the socket is electrically coupled to a radio frequency (RF) generator. 26. The antenna fiber sensor of claim 25, wherein the RF generator is a time-domain reflectometer (TDR) or a vector network analyzer (VNA). 27. The antenna fiber sensor of claim 1, wherein the antenna fiber sensor can sense at least one of a pressure, temperature, proximity of an object, and location in surrounding environment along the length of the antenna fiber sensor.} 2_{8. The antenna fiber sensor of claim 27, wherein the antenna fiber sensor can sense changes in hydrostatic pressure. 29. The antenna fiber sensor of claim 27, wherein the antenna fiber can sense changes in physiological pressure. 30. The antenna fiber sensor of claim 27, wherein the antenna fiber sensor can sense changes in temperature. 31. An antenna fiber sensor system, comprising: i) the antenna fiber sensor of any of claims 1 to 30; ii) radio frequency (RF) generator and receiver and iii) passive or active electronics coupling the RF generator/receiver to the antenna fiber sensor for the choice of the electromagnetic (EM) mode combination.} Docket No. 144578.00411  3^{2. The antenna fiber sensor system of claim 31, wherein the RF generator is a time- domain reflectometer (TDR) or a vector network analyzer (VNA). 33. The system of claim 31 or 32, further comprising a socket positioned at the proximal end of the polymer cladding and coupled to the one or more wires, wherein antenna fiber sensor is electrically coupled to the RF generator through the socket. 34. The system of any one of claims 31 to 33, wherein an electromagnetic signal is transmitted from the RF generator to the one or more wires and reflected back to the RF generator from the one or more wires. 35. The system of claim 34, wherein the RF generator receives the reflected electromagnetic signal from the one or more wires in the antenna fiber sensor to determine a change in characteristic of the antenna fiber sensor.} 3_{6. The system of claim 35, wherein the change in characteristic of the fiber sensor is at least one of a deformation and a location in a surrounding environment. 37. A method for sensing within a vessel using the antenna fiber sensor system of claim 31, the method comprising: inserting the antenna fiber sensor into a vessel; transmitting an electromagnetic signal from the RF generator; receiving a reflected electromagnetic signal at the RF receiver; detecting impedance changes in the reflected electromagnetic signal; converting the detected impedance changes in the reflected electromagnetic signal into a change in characteristic of the antenna fiber sensor; and detecting a location of the change in characteristic along the antenna fiber sensor. 38. The method of claim 37, wherein the electromagnetic signal from the RF generator is a step function.} Docket No. 144578.00411  ^{39. The method of claim 37, wherein the impedance changes are a result of changes in a refractive index of the antenna fiber sensor. 40. The method of claim 39, wherein the refractive index changes as a result of a change in a dielectric constant of the antenna fiber sensor. 41. The method of any one of claims 37-40, wherein the change in characteristic of the antenna fiber sensor is at least one of: a stress causing a deformation at one or more locations along the length of the polymer cladding; a proximity of an object to one or more locations of the antenna fiber sensor; a type of one or more objects causing a deformation at one more locations along the length of the polymer cladding; and a type of one or more objects in proximity to one or more locations of the antenna fiber sensor. 42. The method of claim 41, wherein the type of the object is organic or inorganic.} _{43. The method of claim 41 or claim 42, wherein the deformation is caused by at least one of a blood pressure, a change in blood pressure, a curvature of a vessel, and obstruction of a vessel. 44. The method of claim 43, wherein the deformation is caused by at least one of a pressure in a urinary tract, a change of pressure in a urinary tract, a stricture of a urinary tract, and obstruction of a urinary tract. 45. The method of claim 43, wherein the deformation is caused by at least one of a pressure in a pleural cavity, abdominal cavity, or digestive tract. 46. The method of claim 40, wherein the change in dielectric constant is caused by a change in an environment surrounding the antenna fiber sensor. 47. A method of making an antenna fiber sensor, the method including the steps of:} Docket No. 144578.00411  p^{roducing a polymer cladding preform including one or more channels and one or more passages, wherein the polymer cladding is a composite of a thermoplastic elastomer and a dielectric-constant modifying filler; and thermally drawing the polymer cladding preform with one or more wires feeding into the one or more passages. 48. The method of claim 47, wherein producing the polymer cladding preform further includes the steps of: forming a plurality of planar sheets of the polymer cladding of equal dimensions, wherein a length of each planar sheet is larger than its width; stacking the plurality of planar sheets by their largest surface area such that each outer edge of each planar sheet of the plurality of planar sheets align; and heating the plurality of stacked planar sheets to consolidate the preform.} _{49. The method of claim 48, wherein each planar sheet of the plurality of planar sheets is cut from a larger planer sheet of the polymer cladding. 50. The method of claim 48, wherein the one or more channels and one or more passages are cut along a length of the stack of the plurality of planar sheets using molds. 51. The method of any one of claims 48-50, wherein the plurality of planar sheets is formed and stacked by 3D printing of the polymer cladding. 52. The method of claim 51, wherein the one or more channels and one or more passages are printed in each of the plurality of planar sheets. 53. The method of claim 48, wherein the thermoplastic elastomer and the dielectric- constant modifying filler are mixed in solution before forming the plurality of planar sheets.} Docket No. 144578.00411  ^{54. The method of any one of claims 47-53, wherein the thermoplastic elastomer is selected from the group consisting of styrene-ethylene-butylene-styrene (SEBS), cyclic olefin copolymer (COC), elastomeric cyclic olefin copolymer (ECOC), polysulfone (PSU), poly(methyl methacrylate) (PMMA), polycarbonate (PC), polyvinylidene fluoride (PVDF), polyetherimide (PEI), and polydimethylsiloxane (PDMS). 55. The method of any one of claims 47-54, wherein the dielectric-constant modifying filler is selected from ferroelectric oxides including barium titanate (BaTiO3) and strontium titanate (SrTiO3), metal and transition metal oxides including Calcium copper titanate (CaCu3Ti4O12), La2−xSrxNiO4, and derivates thereof, intrinsic or doped semiconductors including silicon (Si), germanium (Ge), and gallium antimonide (GaSb), and conductors including silver (Ag) and carbon (C).} _{56. The method of any one of claims 47-55, wherein the amount of dielectric-constant modifying filler in the polymer cladding ranges from more than 0% to about 50% by volume. 57. The method any one of claims 47-56, wherein thermally drawing the polymer cladding preform includes: inserting the polymer cladding preform in a preform holder; inserting the one or more wires into the one or more passages; feeding the polymer cladding preform and one or more wires into a heater until a bait-off drops off the polymer cladding preform forming a tapering region and a starting end of the antenna fiber sensor; and grabbing the starting end of the antenna fiber sensor and wrapping it around a capstan and spooling it onto a spool. 58. The method of any one of claims 47-57, wherein the one or more channels extend a length of the polymer cladding preform.} Docket No. 144578.00411  ^{59. The method of any one of claims 47-58, wherein the one or more channels are filled with a dielectric constant-modified liquid. 60. The method of claim 59, wherein the dielectric constant-modified liquid is heated and injected into the one or more channels during the thermal drawing the polymer cladding preform. 61. The method of claim 60, wherein the dielectric constant-modified liquid is manually injected or injected by suction force during the thermal drawing of the polymer cladding preform.} _{62. The method of any one of claims 59-61, wherein the dielectric constant-modified liquid includes one of a colloidal liquid including glycerol or polyethylene glycol doped with barium titanate (BaTiO3) or strontium titanate (SrTiO3). 63. The method of any one of claims 47-62, further including post-processing of the antenna fiber sensor. 64. The method of claim 63, wherein post-processing includes applying pressure at one or more locations along the length of the antenna fiber sensor after heating, providing one or more discrete break-ups in the one or more channels to form one or more pores.}