WO2016123651A1 - Capteurs déformables et procédé de fabrication desdits capteurs au moyen de liquides ioniques - Google Patents

Capteurs déformables et procédé de fabrication desdits capteurs au moyen de liquides ioniques Download PDF

Info

Publication number
WO2016123651A1
WO2016123651A1 PCT/AU2016/000023 AU2016000023W WO2016123651A1 WO 2016123651 A1 WO2016123651 A1 WO 2016123651A1 AU 2016000023 W AU2016000023 W AU 2016000023W WO 2016123651 A1 WO2016123651 A1 WO 2016123651A1
Authority
WO
WIPO (PCT)
Prior art keywords
deformabie
sensor
sensors
liquid
ionic liquid
Prior art date
Application number
PCT/AU2016/000023
Other languages
English (en)
Inventor
Wenlong Cheng
Bin Su
Zheng Ma
Original Assignee
Monash University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from AU2015900370A external-priority patent/AU2015900370A0/en
Application filed by Monash University filed Critical Monash University
Publication of WO2016123651A1 publication Critical patent/WO2016123651A1/fr

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/103—Detecting, measuring or recording devices for testing the shape, pattern, colour, size or movement of the body or parts thereof, for diagnostic purposes
    • A61B5/11—Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/68—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient
    • A61B5/6801—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient specially adapted to be attached to or worn on the body surface
    • A61B5/6802—Sensor mounted on worn items
    • A61B5/6804—Garments; Clothes
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L1/00—Measuring force or stress, in general
    • G01L1/18—Measuring force or stress, in general using properties of piezo-resistive materials, i.e. materials of which the ohmic resistance varies according to changes in magnitude or direction of force applied to the material
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L1/00—Measuring force or stress, in general
    • G01L1/20—Measuring force or stress, in general by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B2560/00—Constructional details of operational features of apparatus; Accessories for medical measuring apparatus
    • A61B2560/04—Constructional details of apparatus
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B2562/00—Details of sensors; Constructional details of sensor housings or probes; Accessories for sensors
    • A61B2562/02—Details of sensors specially adapted for in-vivo measurements
    • A61B2562/0247—Pressure sensors
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B2562/00—Details of sensors; Constructional details of sensor housings or probes; Accessories for sensors
    • A61B2562/02—Details of sensors specially adapted for in-vivo measurements
    • A61B2562/0261—Strain gauges
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B2562/00—Details of sensors; Constructional details of sensor housings or probes; Accessories for sensors
    • A61B2562/12—Manufacturing methods specially adapted for producing sensors for in-vivo measurements
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/68—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient
    • A61B5/6801—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient specially adapted to be attached to or worn on the body surface
    • A61B5/6802—Sensor mounted on worn items
    • A61B5/6804—Garments; Clothes
    • A61B5/6805—Vests
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
    • G01B7/16—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring the deformation in a solid, e.g. by resistance strain gauge

Definitions

  • the present invention relates to the field of sensors and fabrication thereof.
  • the invention in one form, relates to deformab!e sensors comprising ionic liquids.
  • the invention relates to deformabSe sensors for sensing physical parameters such as pressure, strain etcetera.
  • the present invention is suitable for broad technological application for areas ranging from autonomous artificial intelligence, such as electronic skins on robots to wearable health monitors.
  • sensors In more recent times printing, particularly screen-printing has been used to make sensors based on specialised ceramic materials.
  • these types of sensors require a sintering process which is not compatible with the incorporation of plastic components due to melting and deformation.
  • sensors Accordingly, sensors have been developed that are based on inks that can be printed directly onto plastic substrates. They offer significant advantages such as ftexibiiity, thinness and light weight and open up new opportunities for sensor use in association with curved surfaces, ultra-thin devices and shock-resistant devices.
  • ultra-thin, flexible printed circuits are commercially available as sensors for force measurement from Tekscan, Inc in association with their FlexiForce® trade mark. These sensors are used in many applications to detect and measure a relative change i force or applied load, rate of change in force, to defect contact and/or touch and to identify force thresholds and trigger appropriate action.
  • Stretch sensors are soft pieces of flexible polymer that transmit information about the degree to which they are being stretched.
  • Stretch sensors of the prior art typically comprise elastic capacitors made of laminated polymer structure. The capacitance of the structure changes when the sensor is stretched and this change is measured arid related to deformation.
  • Electronic skins are a new class of advanced materials that can be largely pressed, bent, twisted and stretched while maintaining outstanding optoelectronic responses, and will be ke components in future wearable electronics.
  • stretch sensors of the prior art typically have a number of non-ideal characteristics and problems. Stretch sensors often include electrodes that have unpredictable resistance, capacitances are small and susceptible to parasitic effects and there is a complex electromechanical impedanc matching problem at the connections. Sensors based on resistive principles often suffer from drift and rate dependent effects.
  • Stretch sensors have been described in a number of prior art publications including Jvluth et al (Advanced Materials, 2014, 26, 6307) which describes embedded 3D printing of strain sensors within highly stretchable elastomers. Specifically, a new method of embedded 3d printing is reported for fabricating strain sensors within highly conformal and extensible elastomeric matrices. Creation of soft sensors is described, the sensors having nearly arbitrary planar and 3D motifs in a highly programmable and seamless manner.
  • Yoon et al (Advanced Materials, 2014, DOl: 10.1002/adm a.201402588) describes the design and fabrication of novel deformable device arrays on a deformable polymer substrate with embedded liquid-metal interconnections. Active devices attached on stiff islands are electrically connected by an embedded EGaln interconnection, which ensures protection from external damage,
  • Sekitani et al ⁇ Science, 2012, 321 , 1468) describes a rubberSike stretchable active matri manufactured using elastic conductors.
  • WO 2012050938 (Kramer et at) describes wearable tactiie keypads with deformable artificial skin.
  • the patent application describes a hyper-elastic, thin, transparent pressure sensitive keypad fabncated by embedding a silicone rubber film with conductive liquid-filled mtcrochannels.
  • WO 2013044228 (Wood et a!) describes artificial skin and elastic strain sensors. If relates to an elastic strain sensor which can be incorporated into an artificial skin that can sense flexing by the underlying support structure of the skin to detect and track motion of the support structure.
  • resistance-type deformable sensors of this type consist of two crucial components: conductive fillers/coatings and polymeric scaffolds. When stretched under a large strain (e.g. ⁇ > 100%), rigid conductors upon/inside soft polymers are easy to break due to their higher Young's modulus (5-6 orders of magnitude larger than elastomers).
  • An object of the present invention is to provide an improved sensor using ionic liquids.
  • Another object of the present invention is to provide an economical method of fabricating deformable sensors.
  • a further object of the present invention is to alleviate at least one disadvantage associated with the related art.
  • a deformable sensor comprising a deformable substrate and a conducting liquid, preferably an ionic iiquid.
  • the deformable sensor of the present invention is characterised from the deformable sensors of the prior art by the use of conducting liquids, preferably ionic liquids, as the conducting component. Furthermore, the present invention differs from solid-Gonductors/solid substrate (that is, solid-to-solid type) sensor construction, by virtue of the use of a lower Young's modulus conductive material to cooperate with deformable substrates (that is, tiquid-io-solid type sensor construction). 8
  • the present invention typically involves the impregnation or deposition of ionic liquids into or onto eiastomeric structures
  • This ii uid-to-so(id strategy can be widely adapted to various conductive liquids and substrates, preferably elastic substrates.
  • ionic liquids and substrates used in the present invention provides deformable sensors that can work at strain levels up to relatively high values ( ⁇ > 600%).
  • the substrate comprises natural substances, synthetic substances or combinations thereof that individually, or in combination are deformable.
  • the substrate may be siretchafole, bendable, twistable, malleable or ductile.
  • the substrate may comprise an ordered structure, such as woven fibres, or be of random or amorphous structure such as a sponge.
  • the substrate is chosen from the group comprising natural substances such as wool, cotton, skin or hide; synthetic polymers such as polyester, polyethylene, nylon o artificial skin; natural polymers such as rubber.
  • Eiastomeric polymers are particularly preferred and provide a useful scaffold for supporting the ionic liquid.
  • the substrate comprises a fabric, such as a fabric comprising woven synthetic or natural fibres or combinations thereof.
  • Fabric-based deformable sensors according to the present invention are sensitive, stable and exhibit a long life-time. While conductive liquids have been used in pressure sensitive matrixes of the prior art it has not hitherto been known to use the combination of an ionic liquid with a deformable substrate such as a fabric to form a sensor.
  • the sensitivity of deformable sensor according to the present invention has a lower operating limit of about 0,05 % deformation
  • deformable sensors according to the present invention are sufficiently stable that there are negligible loading-unioading signal changes over at least 10,000 cycles.
  • deformable sensors according to the present invention have a lifespan of more than two months. tonic Liquid
  • the ionic liquid should exhibit the properties of (i) low evaporation at ambient temperature and pressure, and (is) adherence to the elastic substrate,
  • Ionic liquids are also colloquially referred to as 'liquid electrolytes 1 , 'ionic melts', 'ionic fluids', fused salts', 'liquid salts' or Ionic glasses'.
  • Ionic liquids comprise ions or ion-pairs forming salt-like materials that are liquid below an arbitrary temperature, such as near ambient temperature, ionic liquids typically have a low vapour pressure, preferably evaporating at much iower rates than water, indicating a long lift-time in ionic liquid state.
  • the typically low Young's modulus, high viscosity and low surface tension (typically -15-35 mN-m "1 , more typically ⁇ 2Q-30 mN-m "1 ) of ionic liquids contribute to their advanced ability to adhere to substrates such as elastomers under a 100 % strain.
  • the ionic liquid of the present invention comprises salts having a tow melting point or low eutectic temperature.
  • the melting point or eutectic temperature is less than ambient temperature, nominally less than about 25 °C, so that they remain fluid at room temperature.
  • the ionic liquid is a eutectic system.
  • a eutectic system is a homogeneous solid mix of atomic and/or chemical species that forms a joint super-lattice, having a unique atomic percentage ratio between the components (as each pure component has its own distinct bulk lattice arrangement ⁇ . It is only in this aiornic mofecuiar ratio that the eutectic system melts as a whole, at a specific temperature (the eutectic temperature) the super lattice releasing at once all its components info a liquid mixture.
  • the eutectic temperature is the lowest possible melting temperature over all of the mixing ratios for the relevant component species.
  • a metallic liquid such as eutectic gallium-indium (EGa!n) has a lower Young's modulus than that of elastoraeric supports and can be used as a ionic liquid in the present invention to provide a iargs-strain-avaiiabie current device.
  • EGaln like most metallic liquids exhibits the drawback of showing poor adhesion to elastic substrates due to its large surface tension ⁇ hundreds of mN m-1) leading to poor spreading and adhesion to the elastic scaffolds.
  • EGain can be used for the present invention if, for example it is sealed inside pre-generated microchannels.
  • the ionic liquid of the present invention is chosen from the group comprising
  • a method of fabricating a deformable sensor according to the present invention including the step of wetting a substrate with a ionic liquid.
  • 'wetting' is intended to refer to the ability of the ionic liquid to maintain contact with the substrate surface, resulting from intermolecuiar interactions when the two are brought together. This may be achieved, for example, by Immersing or dipping the substrate in the ionic liquid, or pouring or dropping the ionic liquid on the substrate.
  • the method of fabrication based on use of ionic liquids is of a generalised, platform nature, being applicable to any type of hydrophiiic/hydrophobic ionic liquid species, and capable of turning virtually any soft elastomeric materials/supports (such as force-spun fibre mats, rubbers, clothes and sponges) into sensors in a simple and rapid manner.
  • any elastomeric objects with dimensions from microscaie to macrosca!e could be converted into a highl deformable, piezoresistive strain sensors in a small experimental timeframe.
  • wetting can be carried out by contacting the elastic substrate with the ionic liquid at least once and preferably multiple times.
  • the method of fabrication or sensors according to the present invention is relatively uncomplicated, importantly, the fabrication time for the sensors of the present invention may be rapid - typically less than half a minute (which corresponds to the time taken for the ionic liquid to wet the substrate).
  • sensors according to the present invention can be patterned by any convenient method such as simple, direct pen writing, 'ink-jet' or stamp printing. Despite such simplicity in fabrication, the sensors of the present invention are capable of functioning at ultra-large strains ( ⁇ * - 00%); high sensitivity down to a Sow-strain of approximately 0.05 %; high durability with negligible loading-unloading signal changes over about 10,000 cycles; washable without the need of sealing; long-term stability after exposing a naked sensor to ambient conditions for >2 months.
  • sensors according to the present invention can be attached to skin or integrated with cloth to enable true wearability, allowing a wide range of body motion tracking and wrist pulse monitoring.
  • the fabrication method of the present invention opens a new powerful route to synthesize piezoresistive sensors with a myriad of applications in future wearable electronics.
  • the present invention thus provides a sensor for attachment to the skin or hide of a human or animal for sensing of physical parameters associated with physiological phenomena.
  • the present invention thus provides a liquid ionic !ayer strategy to prepare deformabie sensors that are relatively simple yet can accommodate high levels of strain and exhibit long lifespan.
  • embodiments of the present invention stem from the realization that ionic liquids can be used as the conducting component in. a deformabie sensor. More particularly, the invention of the present application is based on the realisation that a mechanical match between tonic liquids and substrates can be used to achieve deformabie sensors that can work at relatively high strain. More specifically it has been realised that mechanical mismatch (where the Young's moduli of inorganic conductors are many orders of magnitude larger than that of the soft elastomers) leads to poor long- term durability due, for example to material delamination and/or local fracturing in inorganic components.
  • deformabie sensors of present invention comprise the following: * can work at relatively high strain levels, up to at least 600%;
  • « can be incorporated into skin or wearable fabrics.
  • Stretch sensors of the present application are suitable for a wide range of applications including, but not limited to, the following:
  • autonomous artificial intelligence such as electronic skins on robots
  • FIG. 1 is a schematic illustrating a facile and rapid liquid-to-solid strategy to generate deformabie sensors by simply dropping ionic liquids (6.) upon the network of fibres (2) making up the fabric. Owing to their lower Young's modulus (5 to 6 orders of magnitude smaller than that of elastomers), the ionic liquids typically remain as a thin yet continuous liquid layer (3) even when the fabric has been stretched (4) under a significant strain and recovered (5), yielding a long-stra in-available deformabie sensors.
  • FIG. 2 illustrates current-time characteristics of the fabrication process of ionic liquid infused polymeric fibres during a non-conducting phase (8), fabrication (10), adjustment (12) and establishment of the deformabie sensor (14).
  • fabrication 10
  • adjustment (12)
  • deformabie sensor 14
  • the ionic liquid was directly dropped onto the fibre network by a pipette. After several cycles of stretching, the ionic liquid uniformly spread out upon the fibre surfaces, yielding noise-free, stable and continuous electrical responses after 47 seconds.
  • the fabrication is rapid, adjustment is just 24 seconds and the process is equipment-free.
  • FIG. 3 illustrates the application of the liquid-to-soiid strategy and method of the present invention.
  • FIG. 3 is a digital image of a fibre sheet (20) with an inset scanning electron microscopy (SEM) image of the fibre sheet showing 3D structure.
  • SEM scanning electron microscopy
  • FIG. 6 illustrates the stable electrical performance of ionic liquid infused fibre sheets.
  • Specificall Fig. 6 is a plot illustrating the dependence of electrical resistance on the inducing time by using a plastic plate.
  • the inset image is schematic of plate inducing process
  • FIG. 7 is a plot illustrating the dependence of electrical resistance on the weight ratio of ionic-liquid/fabric. Error bars in FIG. 6 and FIG. 7b, represent standard deviation from testing results for five times. The inset image is schematic of dropping process. Based on the investigation in FIG. 6 and FIG. 7b, the following sample preparations have been fixed at ionic-liquid/fibres weight ratio around 200 %, and underwent the plate inducting treatment for at feast 5 times.
  • FIG. 8 is a strain-response plot for the ionic liquid infused POE fibre sensor.
  • the sensor exhibit a gauge factor (GF) of 1 .11 during 0 % and 600 % strain.
  • FIG. 9 is a plot of resistance change of the sensor as a function of time (input frequency: 0,5 Hz) for the applied strain in the range of 1 % - 200 %: 1 % (21 ), 3% (23), 5% (25), 10% (28), 20% (30), 30% (32), 50% (34), 100% (36), 200% (38).
  • FIG. 10 illustrates the lifespan test under a strain of 10 % at a frequency of 1 Hz.
  • the resistance change curves were recorded after each 2,000 cycles and 200 cycles of data were presented in each recording.
  • the other part of the figure is a magnified view of the part of the AR R0-t curve after 0,000 loading-unloading cycles,
  • FIG. 1 1 is a plot of resistance change of the sensor as a function of time (input strain: 1%) for diverse frequencies including 9 Hz (Fig.11 a), 4 Hz (Fig.1 1 ) and 1.4 Hz (F ' jg.11c), The applied voltage in all the electrical tests was 5 V.
  • FIG. 12 illustrates monitoring of human behaviours using a sensor according to the present invention.
  • the ionic liquid infused POE fibre sheets have been cut Into suitable sizes that were closely attached to the human body.
  • commercial conductive threads were directly sewed upon the two ends of sensors as the source-drain electrodes.
  • FIG. 13 illustrates the potential of ionic liquids to adhere to elastomers even under a large strain.
  • FIG. 13a is a photograph of a 4 ⁇ !_ ionic liquid (1-butyl-2,3-dimethyl- imidazolium tetrafluoroborate) droplet on a flat polyoiefin elastomer (POE) substrate before stretching with a strain of 100 % and having a contact angle of 84.2 ⁇ 1.3°.
  • POE polyoiefin elastomer
  • 13b is a photograph of a 4 pL ionic liquid (1 -butyl-2,3-dimethyl-i ' mida2oli ' um tetrafluoroborate) droplet on a flat polyoiefin elastomer (POE) substrate after stretching with a strain of 100%.
  • FIG. 14 illustrates stable electrical responses of ionic liquid infused cotton fabric or pofyurethane sponge based deforrnabie sensors.
  • FIG. 14a is a plot of resistance change of a cotton fabric based sensor as a function of time (input frequency: 0.5 Hz) for the applied strain in the range of 1% - 50%, that is, 1 % (80), 5% (82), 10% (84), 15% (86), 20% (88), 25% (90), 30% (92), 40% (94) and 50% (96),
  • FIG. 14b is a plot of resistance change of a polyurethane sponge based sensors as a function of time (input frequency: 0.5 Hz) for the applied strain in the range of 1% - 50%.
  • the sample preparations have been fixed at ionic-liquid/fabric o sponge weight ratio around 200 %, and underwent the plate inducting treatment at least 5 times.
  • the applied voltage in all the electrical tests was 5 V.
  • FIG. 15 illustrates steady response to static stretching of ionic liquid infused POE fibre sensors.
  • the sample preparation has been fixed at ionic-iiquid/fibres weight ratio around 200 %, and underwent the plate-inducing treatment for at feast 5 times.
  • the resistance of sensor under each stretching was constant.
  • the detailed l ⁇ V curve shows mechanical loads unde various strains: 0% (100), 1 % (106), 20% (1 12), 40% (116), 100% (120), 200% (124).
  • FIG. 8 illustrates detection of a 0.05 % strain by ionic liquid infused POE fibre sensors according to the present invention.
  • FIG. 16a is a plot of resistance change of fibre based sensors as a function of time (input frequency: 0.5 Hz) for the applied strain in the range of 1 % - 10 %, specifically 10% (130), 9% (132), 8% (134), 7% (136), 6% (138), 5% (140), 4% (142), 3% (144), 2% (146), 1 % (148).
  • FIG. 15b is a piot of resistance change of fibre based sensors as a function of time (input frequency: 0.5 Hz) for the applied strain in the range of 0.1 % (150) and 0.05% (152). The applied voltage in aii the electrical tests was 5 V.
  • FIGS. 17a and 17b illustrates how an ionic liquid infused POE fibre sensor fabricated according to the present invention can respond diverse frequencies from 0.1 to 9 Hz, Plots of resistance change of the sensor as a function of time (input strain: 1%) for diverse frequencies including 9.0 Hz, 8.5 Hz, 7.1 Hz, 5.9 Hz, 9 Hz, 4.0 Hz, 3,2 Hz, 2.9 Hz, 1.3 Hz, 1.0 Hz, 0.3 Hz, 0.2 Hz and 0.1 Hz.
  • the applied voltage in all the electrical tests was 5 V.
  • FIG. 18 illustrates how nodding head behaviour can be monitored b the ionic liquid infused POE fibre sensor. Current-time characteristics of the volunteer nodding her head regularly. The inset images are representative digital images to show the human behaviour during the test. The applied voltage in the electrical test was 5 V,
  • FIG. 19 illustrates plots of resistance change as a function of time for diverse kinds of ionic liquids suitable for use in the present invention using an input frequenc of 0.5hz for the applied strain in the range of 1 % to 50%, specifically 50% (160), 30% (162), 10% (184), 5% (166), 1% (188).
  • the sample preparations were fixed at a sonic liquid/substrate weight ratio around 200%.
  • the applied voltage in all the electrical tests was SV.
  • the ionic liquids used in the tests were as follows:
  • FIG. 19a - tetrabuty!phosphonium methanesulphonate
  • FIG. 19b 1-methyi-3-octylimidazoiium chloride
  • FIG. 19d 1-(3-cyanopropyJ)-c-methylimjdazolium bis(trifluoromethyisulphonyl) amide
  • the ionic liquids of the present invention are room temperature ionic liquids, such as saits with a low melting point ( ⁇ 25°C.) such that they are liquid at room temperature.
  • the evaporate at much lower rates than water, indicating a long lift-time in ionic liquid state, and exhibit high viscosity and low surface tension (**2O-30 rnN-m *1 ⁇ , which contributes to their ability to adhere to a substrate under a 100 % strain (FIG, 13).
  • the ionic liquids can be elongated in response to deformation, such as stretching, of the substrate.
  • the steps of coating, then integration of the ionic liquid onto the substrate is also relatively simple.
  • the ionic liquid can be directly dropped onto the fibre network by a pipette. After several cycles of stretching, the ionic liquid could uniformly spread out upon the fibre surfaces, yielding noise-free, stable and continuous electrical responses after 47 seconds. Owing to reduced thickness and increased length of the ionic liquid layers under a certain strain, the resistance of the sample would increase accordingly.
  • the resistance of the sensor can be described as:
  • Equation 1 Equation 1 where R is the total resistance of the sensor, p is the specific electrical resistance of ILs, Sn is the cross-sectional area of ionic liquids along each fiber/structure.
  • Equation 2 10 where ' is the resistance of the sensor under a certain strain, ⁇ is the strain, ⁇ 5n is the modified factor of each cross-sectional area of ionic liquids along each fibre/structure under the strain.
  • ⁇ is the resistance of the sensor under a certain strain
  • ⁇ 5n is the modified factor of each cross-sectional area of ionic liquids along each fibre/structure under the strain.
  • Rhodamirte B was dissolved in ionic liquid to facilitate observations. Rhodamine B exhibits red fluorescence when exposed to a laser beam having an excitation wavelength at 561.3nm. Before stretching, red fluorescence appeared inside fibre gaps (the fibres have no fluorescence), indicating that the ionic liquid had fully permeating inside the fibre network. When stretched under a 100% strain, several aligned fibre structures can be found parallel to the stretching direction. Notably, red fluorescence covered the whole fibre structure, indicating the existence of continuous ionic liquid layer upon stretched fibre surfaces. The ionic liquid layers became thinned under a strain, leading to the increase of resistance, as described in the Equation 2.
  • the method of the present invention is general and can be used for a wide range of substrates, and is applicable to a wide range of elastomeric scaffolds.
  • elastomeric scaffolds Besides POE fiber mats, other kinds of scaffolds, including ID rubber bands, 2D commercial cotton fabric (FIG. 4), or 3D porous sponges (FIG. 5), could also be wetted by the ionic liquids to generate stretchable sensors within half a minute.
  • the ionic liquids used in the method of the present invention can also be applied to a substrate in any appropriate pattern, simply by a pen delivery. In addition to displaying aesthetic patterns they could simultaneously serve as highly deformable and wearable piezoresistive strain sensors, !n addition, the piezoresistive sensors of the present invention may be washable, particularly if hydrophobic ionic liquids are used, without the need of additional sealing steps.
  • sample preparations were fixed at ionic-liquid/fibres weight ratio around 200 %, and underwent the plate- inducing treatment at least 5 times to obtain a stable resistance of approximately 0.20 MQ-crrf 1 .
  • the amount of ionic liquid required per cm 2 of fibre network is relatively small at about 8.7 mg.
  • Typical cost for the sensor is 2 cents cm 2 based on the typical cost of commercial ionic liquid being AUD$3.14 per gram, which makes this liquid-to-soiid type sensor economic to fabricate.
  • the gauge factor (GF) of a deformable sensor prepared as descri ed above has been tested (FIG. 8).
  • the GF is defined as:
  • the noise-free, stable and continuous responses could be observed at the strain ranged from 1% to 200%.
  • a strain of 0.05% could be detected (FIG. 18), which indicates a 5pm length increase for a 1 ⁇ 1 cm 2 sample.
  • the eyeing stability of as-prepared sensor was tested under a 10 % strain at a frequency of 1 Hz (FIG, 10), The consistent resistance change with strain applied on the sensor could be maintained after 10,000 loading-unloading cycles, implying long working life and reliability of this liquid-to-solid type sensor. Besides this continuous working-life-time test, our sensors can keep their electrical responding ability for more than two months.
  • ionic liquid based piezoresistive sensors according to the present invention can be attached to skin or integrated in cloth, enabling comprehensive body motion and health monitoring.
  • FIG. 12 shows the dependence of resistance on the grip fist behaviour by real-time monitoring of muscle tension/stretching associated with making a fist. About 5% resistance change appeared following rapid systolic diastoiic cycles of the hand muscle.
  • our ionic liquid infused sensor can be used to monitor diverse human physical behaviours. At least two advantages existed in our approach: the first is its facility since the fibre sensor can be directfy sewed onto the cloth, indicating an easy way to integrate the sensor in the cloth fabrication process in future.
  • the other one is our liquid-to-sotid strategy can solve the connect problem between sensor and throughout wires that commonly causes the poor electrical performance in mostly existing wearable sensors.
  • the ionic liquid used in our sensors can stably connect the sensor with the conductive threads due to its fluidity even at a large strain.

Landscapes

  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Molecular Biology (AREA)
  • Animal Behavior & Ethology (AREA)
  • Pathology (AREA)
  • Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Medical Informatics (AREA)
  • General Physics & Mathematics (AREA)
  • Surgery (AREA)
  • Biophysics (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Physiology (AREA)
  • Dentistry (AREA)
  • Oral & Maxillofacial Surgery (AREA)
  • Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)

Abstract

L'invention concerne un capteur déformable et un procédé de fabrication, ledit capteur comprenant un substrat déformable et un liquide conducteur, de préférence un liquide ionique.
PCT/AU2016/000023 2015-02-06 2016-02-04 Capteurs déformables et procédé de fabrication desdits capteurs au moyen de liquides ioniques WO2016123651A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AU2015900370 2015-02-06
AU2015900370A AU2015900370A0 (en) 2015-02-06 Deformable Sensors and Method for Their Fabrication Using Ionic Liquids

Publications (1)

Publication Number Publication Date
WO2016123651A1 true WO2016123651A1 (fr) 2016-08-11

Family

ID=56563221

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/AU2016/000023 WO2016123651A1 (fr) 2015-02-06 2016-02-04 Capteurs déformables et procédé de fabrication desdits capteurs au moyen de liquides ioniques

Country Status (1)

Country Link
WO (1) WO2016123651A1 (fr)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018048479A1 (fr) * 2016-09-12 2018-03-15 Lopez Barron Carlos R Iono-élastomères étirables à réponse mécano-électrique, dispositifs incorporant des iono-élastomères, et procédés de fabrication associés
KR101936841B1 (ko) 2017-03-13 2019-01-11 한국과학기술연구원 플렉서블 직물 센서 이를 포함하는 웨어러블 전자소자 및 이를 이용한 신체 변화 모니터링 방법
KR20190017862A (ko) * 2019-02-14 2019-02-20 울산과학기술원 3d 프린팅을 이용한 소프트 센서, 이의 제조방법 및 이를 적용한 웨어러블 장치
WO2020092747A1 (fr) * 2018-10-31 2020-05-07 Northwestern University Appareil et procédé de mesure de paramètres physiologiques de sujet mammifère et applications associées
CN113701925A (zh) * 2021-09-09 2021-11-26 天津工业大学 一种织物/离子凝胶可穿戴压力传感器件的制备方法
CN114508996A (zh) * 2022-01-26 2022-05-17 河北工业大学 一种感知复杂变形的柔性传感器
US11525842B2 (en) 2018-06-21 2022-12-13 Uchicago Argonne, Llc Multi-purpose sensors using conductive Iono-elastomers
US11885700B2 (en) * 2020-08-28 2024-01-30 Samsung Electronics Co., Ltd. Stretchable strain sensor, combination sensor, and display panel and device

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012050938A2 (fr) * 2010-09-29 2012-04-19 President And Fellows Of Harvard College Pavé de touches tactile vestimentaire avec peau artificielle étirable
WO2012103073A2 (fr) * 2011-01-24 2012-08-02 President And Fellows Of Harvard College Détecteur de courbure élastomère sans mesure des différences de déformation
WO2013044226A2 (fr) * 2011-09-24 2013-03-28 President And Fellows Of Harvard College Peau artificielle et capteur de déformation élastique
WO2014169119A1 (fr) * 2013-04-10 2014-10-16 President And Fellows Of Harvard College Conducteurs ioniques étirables pour des actionneurs et des capteurs transparents
US20150129276A1 (en) * 2013-11-13 2015-05-14 U.S. Army Research Laboratory Attn: Rdrl-Loc-I Deformable Elastomeric Conductors and Differential Electronic Signal Transmission

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012050938A2 (fr) * 2010-09-29 2012-04-19 President And Fellows Of Harvard College Pavé de touches tactile vestimentaire avec peau artificielle étirable
WO2012103073A2 (fr) * 2011-01-24 2012-08-02 President And Fellows Of Harvard College Détecteur de courbure élastomère sans mesure des différences de déformation
WO2013044226A2 (fr) * 2011-09-24 2013-03-28 President And Fellows Of Harvard College Peau artificielle et capteur de déformation élastique
WO2014169119A1 (fr) * 2013-04-10 2014-10-16 President And Fellows Of Harvard College Conducteurs ioniques étirables pour des actionneurs et des capteurs transparents
US20150129276A1 (en) * 2013-11-13 2015-05-14 U.S. Army Research Laboratory Attn: Rdrl-Loc-I Deformable Elastomeric Conductors and Differential Electronic Signal Transmission

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
DING, Y. ET AL.: "Conductivity Trends of PEDOT-PSS Impregnated Fabric and the Effect of Conductivity on Electrochromic Textile", ACS APPLIED MATERIALS & INTERFACES, vol. 2, no. 6, 2010, pages 1588 - 1593 *

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018048479A1 (fr) * 2016-09-12 2018-03-15 Lopez Barron Carlos R Iono-élastomères étirables à réponse mécano-électrique, dispositifs incorporant des iono-élastomères, et procédés de fabrication associés
KR101936841B1 (ko) 2017-03-13 2019-01-11 한국과학기술연구원 플렉서블 직물 센서 이를 포함하는 웨어러블 전자소자 및 이를 이용한 신체 변화 모니터링 방법
US11525842B2 (en) 2018-06-21 2022-12-13 Uchicago Argonne, Llc Multi-purpose sensors using conductive Iono-elastomers
WO2020092747A1 (fr) * 2018-10-31 2020-05-07 Northwestern University Appareil et procédé de mesure de paramètres physiologiques de sujet mammifère et applications associées
KR20190017862A (ko) * 2019-02-14 2019-02-20 울산과학기술원 3d 프린팅을 이용한 소프트 센서, 이의 제조방법 및 이를 적용한 웨어러블 장치
KR102170258B1 (ko) * 2019-02-14 2020-10-26 울산과학기술원 3d 프린팅을 이용한 소프트 센서, 이의 제조방법 및 이를 적용한 웨어러블 장치
US11885700B2 (en) * 2020-08-28 2024-01-30 Samsung Electronics Co., Ltd. Stretchable strain sensor, combination sensor, and display panel and device
CN113701925A (zh) * 2021-09-09 2021-11-26 天津工业大学 一种织物/离子凝胶可穿戴压力传感器件的制备方法
CN114508996A (zh) * 2022-01-26 2022-05-17 河北工业大学 一种感知复杂变形的柔性传感器

Similar Documents

Publication Publication Date Title
WO2016123651A1 (fr) Capteurs déformables et procédé de fabrication desdits capteurs au moyen de liquides ioniques
Peng et al. Conductive polymer nanocomposites for stretchable electronics: material selection, design, and applications
Lo et al. An inkjet-printed PEDOT: PSS-based stretchable conductor for wearable health monitoring device applications
Yang et al. Electronic skin: recent progress and future prospects for skin‐attachable devices for health monitoring, robotics, and prosthetics
Yang et al. Hierarchically microstructure-bioinspired flexible piezoresistive bioelectronics
Guo et al. Recent advances in carbon material‐based multifunctional sensors and their applications in electronic skin systems
You et al. Block copolymer elastomers for stretchable electronics
Chen et al. Superelastic, sensitive, and low hysteresis flexible strain sensor based on wave-patterned liquid metal for human activity monitoring
Georgopoulou et al. Piezoresistive elastomer-based composite strain sensors and their applications
Kwon et al. Highly sensitive, flexible, and wearable pressure sensor based on a giant piezocapacitive effect of three-dimensional microporous elastomeric dielectric layer
Cao et al. Interface-controlled conductive fibers for wearable strain sensors and stretchable conducting wires
Li et al. Smart glove integrated with tunable MWNTs/PDMS fibers made of a one-step extrusion method for finger dexterity, gesture, and temperature recognition
Zhang et al. Breathable and wearable strain sensors based on synergistic conductive carbon nanotubes/cotton fabrics for multi-directional motion detection
Zhou et al. All-nanofiber network structure for ultrasensitive piezoresistive pressure sensors
Jiang et al. Heterogeneous strain distribution of elastomer substrates to enhance the sensitivity of stretchable strain sensors
Niu et al. Advances in flexible sensors for intelligent perception system enhanced by artificial intelligence
US11840798B2 (en) Carbon nanocomposite sensors
Goldoni et al. Stretchable nanocomposite sensors, nanomembrane interconnectors, and wireless electronics toward feedback–loop control of a soft earthworm robot
Ma et al. Highly permeable and ultrastretchable liquid metal micromesh for skin-attachable electronics
Filiatrault et al. A self-assembled, low-cost, microstructured layer for extremely stretchable gold films
Beccatelli et al. All-polymeric pressure sensors based on PEDOT: PSS-modified polyurethane foam
Turgut et al. Thermoplastic elastomer systems containing carbon nanofibers as soft piezoresistive sensors
Jung et al. Linearly sensitive pressure sensor based on a porous multistacked composite structure with controlled mechanical and electrical properties
Bang et al. Ultra-broad linear range and sensitive flexible piezoresistive sensor using reversed lattice structure for wearable electronics
Feng et al. Capacitive sensors with hybrid dielectric structures and high sensitivity over a wide pressure range for monitoring biosignals

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 16745986

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 16745986

Country of ref document: EP

Kind code of ref document: A1