CN117387481A - High-sensitivity and ultra-soft silica gel elastomer strain sensor and preparation method thereof - Google Patents
High-sensitivity and ultra-soft silica gel elastomer strain sensor and preparation method thereof Download PDFInfo
- Publication number
- CN117387481A CN117387481A CN202311423268.1A CN202311423268A CN117387481A CN 117387481 A CN117387481 A CN 117387481A CN 202311423268 A CN202311423268 A CN 202311423268A CN 117387481 A CN117387481 A CN 117387481A
- Authority
- CN
- China
- Prior art keywords
- silica gel
- conductive
- silicone oil
- strain sensor
- layer
- Prior art date
- Legal status (The legal status 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 status listed.)
- Pending
Links
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 title claims abstract description 122
- 239000000741 silica gel Substances 0.000 title claims abstract description 120
- 229910002027 silica gel Inorganic materials 0.000 title claims abstract description 120
- 229920001971 elastomer Polymers 0.000 title claims abstract description 75
- 239000000806 elastomer Substances 0.000 title claims abstract description 75
- 238000002360 preparation method Methods 0.000 title claims abstract description 15
- 239000011231 conductive filler Substances 0.000 claims abstract description 27
- 239000002904 solvent Substances 0.000 claims abstract description 25
- 238000002156 mixing Methods 0.000 claims abstract description 10
- 239000007788 liquid Substances 0.000 claims abstract description 8
- 230000009471 action Effects 0.000 claims abstract description 7
- 238000004806 packaging method and process Methods 0.000 claims abstract description 5
- 229920002545 silicone oil Polymers 0.000 claims description 75
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 claims description 28
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 22
- XDTMQSROBMDMFD-UHFFFAOYSA-N Cyclohexane Chemical compound C1CCCCC1 XDTMQSROBMDMFD-UHFFFAOYSA-N 0.000 claims description 20
- 239000000758 substrate Substances 0.000 claims description 20
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 claims description 18
- 239000000725 suspension Substances 0.000 claims description 17
- 239000000463 material Substances 0.000 claims description 15
- 238000000034 method Methods 0.000 claims description 15
- 239000000243 solution Substances 0.000 claims description 15
- 238000003756 stirring Methods 0.000 claims description 15
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 11
- 239000003054 catalyst Substances 0.000 claims description 11
- 239000012046 mixed solvent Substances 0.000 claims description 11
- 229910052697 platinum Inorganic materials 0.000 claims description 11
- 229920002379 silicone rubber Polymers 0.000 claims description 10
- 229910021389 graphene Inorganic materials 0.000 claims description 7
- 239000002994 raw material Substances 0.000 claims description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 7
- 238000009459 flexible packaging Methods 0.000 claims description 6
- 238000001132 ultrasonic dispersion Methods 0.000 claims description 6
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 claims description 6
- 229920002554 vinyl polymer Polymers 0.000 claims description 6
- 239000011259 mixed solution Substances 0.000 claims description 5
- 229920000036 polyvinylpyrrolidone Polymers 0.000 claims description 5
- 235000013855 polyvinylpyrrolidone Nutrition 0.000 claims description 5
- 239000001267 polyvinylpyrrolidone Substances 0.000 claims description 5
- 229910021393 carbon nanotube Inorganic materials 0.000 claims description 4
- 239000002041 carbon nanotube Substances 0.000 claims description 4
- 238000001338 self-assembly Methods 0.000 claims description 4
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 3
- 125000000118 dimethyl group Chemical group [H]C([H])([H])* 0.000 claims description 3
- 239000004205 dimethyl polysiloxane Substances 0.000 claims description 3
- 235000013870 dimethyl polysiloxane Nutrition 0.000 claims description 3
- GVGUFUZHNYFZLC-UHFFFAOYSA-N dodecyl benzenesulfonate;sodium Chemical compound [Na].CCCCCCCCCCCCOS(=O)(=O)C1=CC=CC=C1 GVGUFUZHNYFZLC-UHFFFAOYSA-N 0.000 claims description 3
- XQSBLCWFZRTIEO-UHFFFAOYSA-N hexadecan-1-amine;hydrobromide Chemical compound [Br-].CCCCCCCCCCCCCCCC[NH3+] XQSBLCWFZRTIEO-UHFFFAOYSA-N 0.000 claims description 3
- 229910052739 hydrogen Inorganic materials 0.000 claims description 3
- 239000001257 hydrogen Substances 0.000 claims description 3
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims description 3
- CXQXSVUQTKDNFP-UHFFFAOYSA-N octamethyltrisiloxane Chemical compound C[Si](C)(C)O[Si](C)(C)O[Si](C)(C)C CXQXSVUQTKDNFP-UHFFFAOYSA-N 0.000 claims description 3
- 238000004987 plasma desorption mass spectroscopy Methods 0.000 claims description 3
- 229920000435 poly(dimethylsiloxane) Polymers 0.000 claims description 3
- 229920000139 polyethylene terephthalate Polymers 0.000 claims description 3
- 238000007639 printing Methods 0.000 claims description 3
- NRHMKIHPTBHXPF-TUJRSCDTSA-M sodium cholate Chemical compound [Na+].C([C@H]1C[C@H]2O)[C@H](O)CC[C@]1(C)[C@@H]1[C@@H]2[C@@H]2CC[C@H]([C@@H](CCC([O-])=O)C)[C@@]2(C)[C@@H](O)C1 NRHMKIHPTBHXPF-TUJRSCDTSA-M 0.000 claims description 3
- 229940080264 sodium dodecylbenzenesulfonate Drugs 0.000 claims description 3
- 239000007787 solid Substances 0.000 claims description 3
- 239000004094 surface-active agent Substances 0.000 claims description 3
- 239000012752 auxiliary agent Substances 0.000 claims description 2
- 239000008119 colloidal silica Substances 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 claims description 2
- -1 mxene Chemical compound 0.000 claims description 2
- 238000005538 encapsulation Methods 0.000 claims 1
- 229920001296 polysiloxane Polymers 0.000 claims 1
- 229910052709 silver Inorganic materials 0.000 claims 1
- 239000004332 silver Substances 0.000 claims 1
- 230000035945 sensitivity Effects 0.000 abstract description 16
- 239000011159 matrix material Substances 0.000 abstract description 12
- 239000012071 phase Substances 0.000 abstract description 9
- 230000003993 interaction Effects 0.000 abstract description 5
- 230000001351 cycling effect Effects 0.000 abstract description 4
- 239000006185 dispersion Substances 0.000 abstract description 4
- 239000008346 aqueous phase Substances 0.000 abstract description 3
- 238000012544 monitoring process Methods 0.000 abstract description 3
- 238000005191 phase separation Methods 0.000 abstract description 3
- 239000010410 layer Substances 0.000 description 82
- 230000008569 process Effects 0.000 description 8
- 239000003921 oil Substances 0.000 description 7
- 230000008859 change Effects 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 5
- 239000000017 hydrogel Substances 0.000 description 5
- 230000007246 mechanism Effects 0.000 description 5
- 229920000642 polymer Polymers 0.000 description 5
- 238000005303 weighing Methods 0.000 description 5
- 239000002390 adhesive tape Substances 0.000 description 4
- 239000011229 interlayer Substances 0.000 description 4
- 229910021392 nanocarbon Inorganic materials 0.000 description 4
- 230000004044 response Effects 0.000 description 4
- 230000004043 responsiveness Effects 0.000 description 4
- 238000009864 tensile test Methods 0.000 description 4
- 230000008901 benefit Effects 0.000 description 3
- 238000005520 cutting process Methods 0.000 description 3
- 238000013461 design Methods 0.000 description 3
- AMTWCFIAVKBGOD-UHFFFAOYSA-N dioxosilane;methoxy-dimethyl-trimethylsilyloxysilane Chemical compound O=[Si]=O.CO[Si](C)(C)O[Si](C)(C)C AMTWCFIAVKBGOD-UHFFFAOYSA-N 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 239000002086 nanomaterial Substances 0.000 description 3
- 238000011160 research Methods 0.000 description 3
- 229940083037 simethicone Drugs 0.000 description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- 230000006399 behavior Effects 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 238000004132 cross linking Methods 0.000 description 2
- 125000004122 cyclic group Chemical group 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 239000000945 filler Substances 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 239000002608 ionic liquid Substances 0.000 description 2
- 239000007791 liquid phase Substances 0.000 description 2
- 238000005461 lubrication Methods 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000005020 polyethylene terephthalate Substances 0.000 description 2
- 239000004814 polyurethane Substances 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 238000009210 therapy by ultrasound Methods 0.000 description 2
- 229920002799 BoPET Polymers 0.000 description 1
- 239000006087 Silane Coupling Agent Substances 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 229920001940 conductive polymer Polymers 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 239000012776 electronic material Substances 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 229920005570 flexible polymer Polymers 0.000 description 1
- 239000000499 gel Substances 0.000 description 1
- 238000010329 laser etching Methods 0.000 description 1
- 239000002346 layers by function Substances 0.000 description 1
- 238000011068 loading method Methods 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 210000000056 organ Anatomy 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 238000007650 screen-printing Methods 0.000 description 1
- 230000008054 signal transmission Effects 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 239000007779 soft material Substances 0.000 description 1
- 210000004872 soft tissue Anatomy 0.000 description 1
- 238000000935 solvent evaporation Methods 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 210000000707 wrist Anatomy 0.000 description 1
Classifications
-
- 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
- G01B7/18—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring the deformation in a solid, e.g. by resistance strain gauge using change in resistance
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B13/00—Apparatus or processes specially adapted for manufacturing conductors or cables
- H01B13/0026—Apparatus for manufacturing conducting or semi-conducting layers, e.g. deposition of metal
Abstract
The invention provides a high-sensitivity and ultra-soft silica gel elastomer strain sensor and a preparation method thereof. Uniformly mixing the aqueous phase dispersion liquid of the conductive filler and the oil phase dispersion liquid of the silica gel prepolymer, and standing to volatilize the solvent. Under the driving actions of water-oil phase separation and solvent volatilization, the conductive filler and the silica gel molecular chain respectively form a crack conductive layer and a soft matrix layer to form the conductive silica gel elastomer with an upper-lower layered structure. The lead and the packaging layer are introduced to obtain the strain sensor capable of outputting an electrical signal. The silica gel elastomer strain sensor has high sensitivity, supersoftness and excellent cycling stability, and has wide application prospects in the aspects of human motion monitoring, flexible actuators, human-computer interaction and the like.
Description
Technical Field
The invention relates to the technical field of flexible sensors, in particular to a high-sensitivity and ultra-soft silica gel elastomer strain sensor and a preparation method thereof.
Background
Strain sensors based on ultra-soft electronic materials have been receiving attention for their excellent compliance and modulus matching with soft tissues, for simulating biological system sensing behavior, detecting vital signs, improving man-machine interaction, and giving the flexible robot body and external sensing a strong irreplaceability. Materials with intrinsic flexibility and stretchability, such as hydrogels, ionic elastomers, silicone elastomers, and the like, have attracted considerable research attention. The hydrogel and the ionic elastomer have high content of water or expensive ionic liquid, so that the use environment of the hydrogel and the ionic elastomer is greatly limited. The silica gel elastomer has excellent stability and biocompatibility, well makes up the defects of hydrogel and ionic elastomer, and becomes one of the most widely applied materials. The conductivity of silica gel elastomers depends on the conductive network formed by high doping levels of conductive fillers (CNT, carbon black, metals, nanosilver, etc.), however, the fillers are difficult to avoid slipping during repeated stretching cycles, resulting in an unstable electron transport path. More importantly, due to the lack of structural design of a conductive network, the sensitivity mechanism of the strain sensor prepared based on the ultra-soft material (hydrogel, ionic gel and silica gel elastomer) at present only depends on the poisson effect of the material, and significant resistance change can be generated when the material is subjected to large deformation, so that the sensitivity is generally low. The improvement of the sensitivity of the ultra-soft strain sensor has important significance for accurately transmitting electric signals and detecting the shape of soft machinery and sensing mechanics, but the prior research technology cannot be effectively realized.
The fact that the material has a conductive structure that is highly sensitive to minute strains is critical to the ultra-high sensitivity of the flexible sensor. Inspired by the biological crack-shaped slit organ, the preparation of the multi-layer structure sensor containing the conductive functional layer and the introduction of the microcrack structure in the conductive layer are considered to be effective ways for improving the strain sensitivity of the sensor. Much work reports on related research and patented technology. For example, micro cracks are manufactured in the conductive layer by means of sputtering deposition (patent CN114136203A, CN113074622A, CN114045467 a), screen printing (patent CN113897596 a) and laser etching (patent CN113551791 a), and then the micro cracks are encapsulated by flexible polymers, so that the strain sensor has extremely high strain sensitivity. However, these methods involve complex processes and the conductive layer material is typically a metal or conductive polymer with a relatively high modulus, which lacks stretchability due to rigidity/brittleness, resulting in a non-matching high modulus, narrow strain sensing range (typically below 20%). Another idea is to apply one-or two-dimensional conductive nanomaterials, such as carbon nanotubes, graphene or Mxene, and spray droplets onto a flexible substrate as a strain sensing layer (patent CN114941980a, patent CN114963963a, patent CN 110823085B). Under strain, the overlapping one-or two-dimensional nanomaterial may slip and form cracks to exhibit abrupt resistance changes. However, the weak interfacial adhesion between the conductive filler and the flexible substrate or other conductive fillers causes the conductive network to be easily damaged under cyclic or repeated loading, and the conductive layer undergoes crack growth and partial peeling, so that the sensor has poor cyclic stability and durability. Even though the silane coupling agent can improve the interfacial adhesion between the conductive layer and the flexible substrate to some extent to improve the sensing performance, the softness, sensitivity and durability of the sensor are still unsatisfactory. The mismatch of modulus of the ultra-soft matrix and the filler can further aggravate the modulus mismatch and fatigue failure of the interface, and how to design and manufacture the ultra-soft strain sensor with ultra-sensitive characteristics is still a technical challenge to be solved at present.
Disclosure of Invention
Aiming at the defects of the prior art, the invention aims to provide a high-sensitivity and ultra-soft silica gel elastomer strain sensor and a preparation method thereof. Uniformly mixing the aqueous dispersion liquid of the conductive filler/isopropanol with the oily dispersion liquid of the silica gel prepolymer/cyclohexane/silicone oil, and driving the conductive filler to self-assemble into a crack conductive layer on the silica gel matrix by utilizing water-oil phase separation and volatilization of a low-boiling-point aqueous phase solvent, wherein an embedded and interlocked interlayer interface structure is formed between the bottom of the conductive layer and the silica gel matrix. At the same time, silicone oil deposited on the lower layer is filled in the cross-linked and solidified silica gel matrix and used as a lubricant among silica gel molecular chains to reduce friction energy consumption of chain segments during deformation, so that the material shows high softness and elasticity. The preparation method fully utilizes the crack conduction mechanism of the conductive layer, the silicone oil lubrication effect of the substrate layer and the strong interface combination of the interlayer embedded interlocking structure, so that the obtained silica gel elastomer strain sensor has high sensitivity, high softness and excellent cycling stability, and has wide application prospects in the aspects of human body motion monitoring, flexible actuators, human-computer interaction and the like.
The aim of the invention can be achieved by the following scheme:
in a first aspect, the invention provides a high-sensitivity and ultra-soft silica gel elastomer strain sensor, which comprises a flexible packaging layer, a crack conducting layer and a flexible substrate layer which are sequentially stacked from top to bottom.
As one embodiment of the invention, the two ends of the crack conductive layer are respectively provided with conductive silver paste, the upper surface of each conductive silver paste is provided with a wire, and the two ends of the crack conductive layer are respectively connected with the wires. The invention prints out the lead (namely the conductive line) by taking the conductive silver paste as the raw material.
Further, the length of the cracked conductive layer is less than the length of the flexible substrate layer.
In the invention, one end of a wire is respectively connected with two ends of a crack conducting layer, and the other end of the wire is respectively connected with an electrode.
As one embodiment of the present invention, the crack conductive layer is connected with the flexible substrate layer by an embedded interlocking interlayer interface structure.
In some embodiments, the conductive filler nanocarbon and graphene constitute a crack conductive layer.
As one embodiment of the invention, the flexible substrate layer comprises a silica gel polymer molecular chain (namely a silica gel elastomer) and silicone oil; the silicone oil is filled in the molecular chain of the crosslinked silica gel polymer to form a flexible matrix layer.
As one embodiment of the invention, the crack conductive layer is formed by self-assembly of the conductive filler at a gas-liquid interface under the driving action of solvent volatilization.
As one embodiment of the present invention, the conductive filler comprises all nanofillers that can be dispersed in an isopropanol solvent and have self-assembling properties.
Further, the conductive filler includes at least one of carbon nanotubes (nano carbon), graphene, mxene, and conductive carbon black.
As one embodiment of the invention, the flexible substrate layer is a silicone elastomer filled with silicone oil, and the silicone elastomer is formed by chemically crosslinking vinyl-terminated silicone oil, hydrogenated silicone oil and a platinum-based Karstedt catalyst.
Further, the viscosity of the vinyl-terminated silicone oil is 20000 to 60000cps; the hydrogen content of the hydrogenated silicone oil is 0.2-0.5%, and the viscosity is 200-800 cps; the purity of the platinum-based Karstedt catalyst is 500-5000 ppm.
As one embodiment of the present invention, the viscosity of the filled silicone oil is 300 to 800cps.
As one embodiment of the present invention, the conductive line layer is a conductive line, and the conductive line is disposed at both ends of the crack conductive layer.
As one embodiment of the present invention, the flexible material used for the flexible packaging layer includes PDMS, PET, silica gel, PU, medical tape, and modified products of the above materials.
In a second aspect, the present invention provides a method for preparing a highly sensitive, ultra-soft silica gel elastomer strain sensor, the method comprising the steps of:
step S1: dispersing conductive filler in isopropanol solvent, adding dispersing auxiliary agent, and obtaining conductive component suspension after ultrasonic dispersion;
step S2: uniformly stirring vinyl-terminated silicone oil and hydrogenated silicone oil to obtain a silica gel prepolymer; adding the silica gel prepolymer into a mixed solvent of silicone oil/cyclohexane, and stirring to obtain a silica gel prepolymer solution;
step S3: pouring the conductive component suspension in the step S1 into the silica gel prepolymer solution in the step S2, adding a platinum-based Karstedt catalyst after stirring, pouring the mixed solution into a mould, and standing to form the conductive silica gel elastomer with an upper-lower layered structure; the upper structure of the conductive silica gel elastomer is a crack conductive layer, and the lower structure of the conductive silica gel elastomer is a flexible substrate layer;
step S4: respectively pouring conductive silver paste into two ends of the crack conductive layer, printing out a wire by taking the conductive silver paste as a raw material, respectively connecting two ends of the crack conductive layer with one end of the wire, and leading out the other end of the wire; and packaging the lead and the crack conducting layer by using a flexible material to obtain the high-sensitivity and ultra-soft silica gel elastomer strain sensor.
As one embodiment of the present invention, in the step S1, the ultrasonic dispersion time is 0.5 to 2 hours.
In step S1, as an embodiment of the present invention, the dispersing aid includes at least one of water-based surfactants such as polyvinylpyrrolidone, sodium dodecylbenzenesulfonate, sodium cholate, and cetylammonium bromide; the dispersing auxiliary accounts for 0.02-0.2 wt% of the isopropanol solvent.
As an embodiment of the invention, in step S1, the solid content of the conductive component suspension is 0.05 to 5wt%.
As an embodiment of the present invention, in step S2, the mass ratio of the vinyl-terminated silicone oil to the hydrogenated silicone oil is 8 to 15:1, the mixing ratio of the silicone oil and the cyclohexane in the silicone oil/cyclohexane mixed solvent is 6-1.5: 1, the dosage ratio of the silica gel prepolymer to the silicone oil/cyclohexane mixed solvent is 1g: 4-12 ml. The silicone oil in the silicone oil/cyclohexane mixed solvent is dimethyl silicone oil.
As one embodiment of the present invention, in the step S2, the stirring time is 0.5 to 2 hours. In the invention, molecular chains in the silica gel prepolymer solution are fully swelled.
As an embodiment of the present invention, in step S3, the volume ratio of the conductive component suspension to the colloidal silica prepolymer solution is 1 to 3:1.
in the standing process of the step S3, the isopropanol gradually phase separates from the silicone oil, migrates to the upper layer of the silicone oil and volatilizes rapidly. The conductive filler with the polarity similar to that of the isopropanol moves to the gas-liquid interface under the driving action of solvent volatilization, and self-assembles at the interface to form a crack conductive layer. The lower silica gel molecular chain is crosslinked and solidified along with the volatilization of the solvent, and the silicone oil is filled in the crosslinked silica gel molecular chain to form a flexible basal layer. Thus, a conductive silicone elastomer having an upper and lower layered structure was obtained.
As an embodiment of the present invention, in step S3, the conductive silicone elastomer is cut into an arbitrary rectangle. In the invention, the other end of the conductive line is led out and then connected with the electrode.
Compared with the prior art, the invention has the following beneficial effects:
1. the response mechanism of the silica gel elastomer strain sensor prepared by the invention is an electronic crack conduction mechanism, and has the remarkable advantages of high sensitivity and high response speed. Under the action of tensile load, cracks of the conductive layer rapidly proliferate and expand, and the transmission path of electrons is prolonged and blocked, so that the conductivity of the sensor is rapidly changed.
2. The silica gel elastomer strain sensor prepared by the invention has high flexibility, high adhesiveness and stretchability, so that the silica gel elastomer strain sensor has good compliance to surfaces with different shapes, can be tightly adhered to the surface of skin or an object to be monitored and can deform under the action of external force, thereby effectively enhancing the fidelity of signal acquisition and ensuring high-quality transmission of signals.
3. The strain sensor of the silica gel elastomer prepared by the invention has stable component property, does not contain water, ionic liquid or other volatile and leaked organic solvents, and has excellent environmental stability under water, at low temperature (-20 ℃), at high temperature (100 ℃) and at normal temperature.
4. The invention skillfully utilizes the phase separation of the water-oil mixed solvent and the solvent evaporation to drive the conductive filler to self-assemble into the conductive film on the surface of the flexible matrix, thus obtaining the strain sensor with the conductive layer. The strategy is simple and efficient, does not involve complex processing equipment and process, and is widely applicable to most conductive fillers and silica gel systems.
5. The preparation strategy provided by the invention has the advantages that the bottom of the conductive layer is embedded into the flexible substrate layer, and a strong interface combination is formed between the conductive layer and the flexible substrate layer, which is obviously different from the coating method (namely, the slurry of the conductive nano material is directly coated on the surface of the flexible substrate) used for preparing the crack strain sensor in the prior art. This allows the conductive network of the strain sensor to recover completely under a stretching cycle, giving the strain sensor excellent electrical sensing stability and cycling stability.
6. The silica gel elastomer strain sensor prepared by the invention has wide application prospect in the fields of simulating biological system sensing behaviors, detecting vital signs, improving human-computer interaction, and body and external sensing of a flexible robot and the like due to ultrahigh softness and compliance, high sensitive electrical signal responsiveness and excellent environmental stability.
Drawings
Other features, objects and advantages of the present invention will become more apparent upon reading of the detailed description of non-limiting embodiments, given with reference to the accompanying drawings in which:
FIG. 1 is a schematic structural view and a schematic sectional structural view of a silica gel elastomer strain sensor prepared in example 1;
FIG. 2 is a photomicrograph of the silica gel elastomer strain sensor prepared in example 1 at various tensile strains; wherein (a) - (d) correspond to the tensile strain of the sensor being 0%,10%,20%,30% respectively, and (e) correspond to the initial strain state after the sensor is stretched;
FIG. 3 is a stress-strain curve of the silica gel elastomer strain sensor prepared in example 1;
FIG. 4 is a graph showing the resistivity change rate versus strain for the silica gel elastomer strain sensor prepared in example 1;
FIG. 5 is a stress-strain curve of the silica gel elastomer strain sensor prepared in comparative example 1;
FIG. 6 is a graph showing the resistivity change rate versus strain of the silica gel elastomer strain sensor prepared in comparative example 1;
reference numerals illustrate:
1. a flexible packaging layer, 2, a wire, 3, conductive silver paste, 4, a crack conductive layer, 5, a flexible matrix layer, 6, a conductive filler, 7, a silica gel polymer molecular chain, 8 and silicone oil.
Detailed Description
The invention will now be described in detail with reference to the drawings and specific examples. The following examples, which are presented to provide those of ordinary skill in the art with a detailed description of the invention and to provide a further understanding of the invention, are presented in terms of implementation and operation. It should be noted that the protection scope of the present invention is not limited to the following embodiments, and several adjustments and improvements made on the premise of the inventive concept are all within the protection scope of the present invention.
In order that the invention may be readily understood, a more complete description of the invention will be rendered by reference to the appended drawings. Preferred embodiments of the present invention are shown in the accompanying drawings. The foregoing description is only of the preferred embodiments of the present invention, and is not intended to limit the scope of the invention, but rather is intended to cover any equivalents of the structures disclosed herein or modifications in equivalent processes, or any application of the structures disclosed herein, whether or not they are directly or indirectly related, as would be within the scope of the invention.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.
In a specific implementation process, the high-sensitivity and ultra-soft silica gel elastomer strain sensor and the preparation method thereof are as follows:
the high-sensitivity and ultra-soft silica gel elastomer strain sensor comprises a flexible packaging layer 1, a crack conducting layer 4 and a flexible substrate layer 5 which are sequentially laminated from top to bottom; conductive silver paste 3 is arranged at two ends of the crack conductive layer, a lead 2 is printed by taking the conductive silver paste as a raw material, and two ends of the crack conductive layer are respectively connected with the lead; the conductive filler 6 constitutes a crack conductive layer; the flexible substrate layer comprises a silica gel polymer molecular chain 7 and silicone oil 8, wherein the silicone oil is filled in the crosslinked silica gel polymer molecular chain to form the flexible substrate layer; the conductive silver paste is used for fixing the connection between the two ends of the crack conductive layer and the wires. The crack conductive layer is formed by self-assembly of conductive filler at a gas-liquid interface under the driving action of solvent volatilization. The conductive filler comprises all nanofillers which can be dispersed in isopropanol solvent and have self-assembly characteristics including, but not limited to, carbon nanotubes, graphene, mxene, conductive carbon black, and any combination of the above. The soft substrate layer is a silicone elastomer filled with silicone oil. The silica gel elastomer is formed by chemically crosslinking vinyl-terminated silicone oil, hydrogenated silicone oil and a platinum-based Karstedt catalyst, wherein the viscosity of the vinyl-terminated silicone oil is 20000-60000 cps; the hydrogen content of the hydrogenated silicone oil is 0.2-0.5%, and the viscosity is 200-800 cps; the purity of the platinum-based Karstedt catalyst is 500-5000 ppm. The viscosity of the filled silicone oil is 300-800 cps. The conducting wire is a conducting line arranged on the flexible medical adhesive tape, and the flexible material adopted by the flexible packaging layer comprises PDMS, PET, silica gel, PU, medical adhesive tape and modified products of the materials.
The preparation method of the high-sensitivity and ultra-soft silica gel elastomer strain sensor comprises the following steps:
step S1: dispersing the conductive filler in isopropanol solvent, adding dispersing auxiliary, and performing ultrasonic dispersion for 0.5-2h until a uniformly dispersed conductive component suspension is obtained. Wherein, the dispersing auxiliary comprises, but is not limited to, surfactant polyvinylpyrrolidone, sodium dodecyl benzene sulfonate, sodium cholate, cetyl ammonium bromide and the like; the dispersing auxiliary accounts for 0.02-0.2 wt% of the isopropanol solvent. The solids content of the conductive component suspension is 0.05 to 5 wt.%, preferably 0.1 to 1 wt.%.
Step S2: uniformly stirring vinyl-terminated silicone oil and hydrogenated silicone oil to obtain a silica gel prepolymer; adding the silica gel prepolymer into a mixed solvent of silicone oil and cyclohexane, and fully stirring for 0.5-2h to obtain a silica gel prepolymer solution with fully swelled molecular chains. Wherein the mass ratio of the vinyl-terminated silicone oil to the hydrogenated silicone oil is 8-15:1, preferably 10-12:1, a step of; the mixing ratio of the silicone oil to the cyclohexane is 6-1.5: 1, a step of; the ratio of the prepolymer to the silicone oil/cyclohexane mixed solvent was 1g: 4-12 ml.
Step S3: and (3) pouring the conductive component suspension in the step (S1) into the silica gel prepolymer solution in the step (S2), adding a platinum-based Karstedt catalyst after ultrasonic stirring, and finally pouring the mixed solution into a mould for standing. After the solvent volatilizes, the silica gel elastomer with a crack conducting layer and matrix layer double-layer structure is obtained.
Step S4: cutting the conductive silica gel elastomer with the double-layer structure in the step S3 into any rectangle; and respectively pouring conductive silver paste into two ends of the crack conductive layer, printing out a wire by taking the conductive silver paste as a raw material, connecting one end of the wire with one end of the conductive layer of the rectangular elastomer, and leading out the other end of the wire to be connected with the electrode. And finally, packaging the conductive lines and the conductive layer with the crack structure by using a flexible material, and finally obtaining the high-sensitivity and ultra-soft silica gel elastomer strain sensor.
The invention is further illustrated below in connection with examples, but the inventive content is not limited to only these examples:
example 1
In this embodiment, the preparation method of the high-sensitivity and ultra-soft silica gel elastomer strain sensor is as follows:
step 1: a uniformly dispersed aqueous phase conductive component suspension is prepared. Weighing 30mg according to the mass ratio of 1:1, dispersing the nano carbon and the graphene serving as conductive fillers in 15ml of isopropanol solvent, adding 8mg of polyvinylpyrrolidone, and performing ultrasonic dispersion for 1h to obtain a uniformly dispersed conductive component suspension.
Step 2: preparing a silica gel prepolymer solution of an oil phase. The viscosity was formulated to 5000cps by mixing vinyl terminated silicone oils of different viscosities at 10:1, respectively weighing vinyl-terminated silicone oil with the viscosity of 5000cps and hydrogenated silicone oil with the viscosity of 800cps, and fully stirring the vinyl-terminated silicone oil and the hydrogenated silicone oil to obtain the silica gel prepolymer. 1g of silica gel prepolymer, 6ml of simethicone and 4ml of cyclohexane are weighed, the silica gel prepolymer and the dimethyl silicone oil are added after being uniformly mixed, and the mixture is stirred for 1h, so that the molecular chain of the silica gel prepolymer is fully swelled in a cyclohexane solvent.
Step 3: preparing a silica gel elastomer. And (3) uniformly mixing the conductive suspension obtained in the step (1) with the silica gel prepolymer solution obtained in the step (2), and stirring for 30min after ultrasonic treatment for 30min to obtain a liquid phase system with fully mixed water phase/oil phase. And (3) dropwise adding a platinum-based Karstedt catalyst into the mixed system, and finally pouring the mixed solution into a mould for standing. After the solvent volatilizes, the silica gel elastomer with a crack conducting layer and matrix layer double-layer structure is obtained.
Step 4: a silica gel elastomer strain sensor was prepared. Cutting the conductive silica gel elastomer with the double-layer structure obtained in the step 3 into strip rectangles with the length of 30mm and 5 mm. Conductive silver paste is used as a raw material, conductive lines are printed on a medical adhesive tape, one ends of the conductive lines are respectively connected to two sides of an elastomer conductive layer, and the other ends of the conductive lines are led out to be connected with a copper electrode. And finally, dripping a silica gel solution on the surfaces of the electrode layer and the conductive layer to encapsulate the conductive lines and the conductive layer with the crack structure, thereby obtaining the silica gel elastomer strain sensor. A structural schematic diagram and a cross-sectional structural schematic diagram of the silica gel elastomer strain sensor are shown in FIG. 1.
And (5) carrying out mechanical tensile test on the prepared silica gel elastomer strain sensor by adopting a universal tester. The tensile test was conducted by clamping both ends of the strip with a clamp of the tester, and the tensile rate was set to 50mm/min. The stress strain curve of the silica gel elastomer strain sensor is shown in fig. 3. Wherein, the abscissa Stress represents Strain (%), and the ordinate Stress represents Stress (kPa). Young's Modulus, the value of which is the slope of the linear segment of the stress-strain curve. The Young's modulus of the sensor obtained according to the stress strain curve is only 8.53kPa, and the sensor has high flexibility. The photomicrographs of the silica gel elastomer strain sensor under different tensile strains are shown in fig. 2, wherein (a) - (d) respectively correspond to the tensile strain of the sensor to be 0%,10%,20% and 30%, and (e) corresponds to the initial strain state after the sensor is stretched. Can be adhered to the back of skin (finger, back of hand, wrist) by self-adhesion, and can be elongated and deformed along with bending motion of human joints without falling off from the skin surface. And detecting the electrical signal responsiveness of the silica gel elastomer strain sensor. Using universal useThe testing machine controls and records the strain of the sensor in the stretching process, and meanwhile, a digital source meter is adopted to record the signal change of the sensor in the stretching process. The resulting resistivity-strain curve of the silica gel elastomer strain sensor is shown in FIG. 4, in which the ordinate ΔR/R 0 Represents the rate of change (%) of resistance; GF represents sensitivity and the value is the slope of the resistivity-strain curve. The strain range detectable by the sensor is up to 50%, and the sensitivity factor is up to 260.7. The sensor response curve was not significantly changed during 1000 stretch-release cycles, with good durability and reliability.
Example 2
In this embodiment, the preparation method of the high-sensitivity and ultra-soft silica gel elastomer strain sensor is as follows:
step 1: a uniformly dispersed aqueous conductive suspension was prepared. Weighing 50mg according to the mass ratio of 1:1, dispersing the nano carbon and the graphene serving as conductive fillers in 20ml of isopropanol solvent, adding 10mg of polyvinylpyrrolidone, and performing ultrasonic dispersion for 1h to obtain a uniformly dispersed conductive suspension.
Step 2: preparing a silica gel prepolymer solution of an oil phase. The viscosity was formulated to 7000cps by mixing vinyl terminated silicone oils of different viscosities at 10:1, respectively weighing terminal vinyl silicone oil with the viscosity of 7000cps and hydrogenated silicone oil with the viscosity of 800cps, and fully stirring the terminal vinyl silicone oil and the hydrogenated silicone oil to obtain the silica gel prepolymer. 1.2g of silica gel prepolymer, 7ml of simethicone and 4ml of cyclohexane are weighed, the silica gel prepolymer and the simethicone are added after being uniformly mixed, and the mixture is stirred for 1h, so that the molecular chains of the silica gel prepolymer are fully swelled in a cyclohexane solvent.
Step 3: and (3) uniformly mixing the conductive suspension obtained in the step (1) with the silica gel prepolymer solution obtained in the step (2), and stirring for 30min after ultrasonic treatment for 30min to obtain a liquid phase system with fully mixed water phase/oil phase. And (3) dropwise adding a platinum-based Karstedt catalyst into the mixed system, and finally pouring the mixed solution into a mould for standing. After the solvent volatilizes, the silica gel elastomer with a crack conducting layer and matrix layer double-layer structure is obtained.
Step 4: and (3) cutting the conductive silica gel elastomer with the double-layer structure obtained in the step (3) into a strip rectangle with the length of 20mm and 6 mm. Conductive silver paste is used as a raw material, conductive lines are printed on a medical adhesive tape, one ends of the conductive lines are respectively connected to two sides of an elastomer conductive layer, and the other ends of the conductive lines are led out to be connected with a copper electrode. And finally, directly sticking and packaging the conductive lines and the conductive layers with the crack structures by using a flexible PET film to obtain the silica gel elastomer strain sensor.
And the mechanical tensile test is carried out on the prepared silica gel elastomer strain sensor, and the elastic modulus of the sensor is only 13.53kPa, so that the sensor has high softness and elasticity. The electrical signal responsiveness of the silica gel elastomer strain sensor is detected, the detectable strain range of the sensor is up to 50%, and the sensitivity factor is up to 405.6. The sensor response curve was not significantly changed during 1000 stretch-release cycles, with good durability and reliability.
Comparative example 1
The preparation method of this comparative example is basically the same as that of example 1, except that step 2: preparing a silica gel prepolymer solution of an oil phase. The viscosity was formulated to 5000cps by mixing vinyl terminated silicone oils of different viscosities at 10:1, respectively weighing vinyl-terminated silicone oil with the viscosity of 5000cps and hydrogenated silicone oil with the viscosity of 800cps, and fully stirring the vinyl-terminated silicone oil and the hydrogenated silicone oil to obtain the silica gel prepolymer. 1g of silica gel prepolymer and 10ml of cyclohexane are weighed, the silica gel prepolymer and the silica gel prepolymer are added after being uniformly mixed, and the mixture is stirred for 1h, so that the molecular chains of the silica gel prepolymer are fully swelled in a cyclohexane solvent.
The prepared silica gel elastomer strain sensor is a composite material with conductive filler uniformly dispersed in the silica gel elastomer. The resulting samples were subjected to mechanical tensile testing, the test procedure being consistent with example 1. The stress strain curve of the silica gel elastomer strain sensor is shown in fig. 5. Wherein, the abscissa Stress represents Strain (%), and the ordinate Stress represents Stress (kPa). Young's Modulus, the value of which is the slope of the linear segment of the stress-strain curve. The Young's modulus of the sensor obtained from the stress strain curve was 70.1kPa, and a high Young's modulus indicates that the softness of comparative example 1 was significantly lower than that of example 1. Method for detecting and testing electrical signal responsiveness of silica gel elastomer strain sensorConsistent with example 1. The resulting resistivity-strain curve of the silica gel elastomer strain sensor is shown in FIG. 6, in which the ordinate ΔR/R 0 Represents the rate of change (%) of resistance; GF represents sensitivity and the value is the slope of the resistivity-strain curve. From the calculation, the sensitivity factor of the sensor is only 1.81 at the highest, which is far lower than the result of example 1.
Example results show that the silica gel elastomer strain sensor prepared by the invention exhibits high sensitivity, ultra-low modulus and excellent cycling stability due to crack conduction mechanism of the conductive layer, silicone oil lubrication effect of the matrix layer and strong interface bonding of the interlayer embedded interlocking structure. The strain sensor has wide application prospect in the aspects of human motion monitoring, flexible executors, human-computer interaction and the like. In addition, the preparation method of the strain sensor is simple and efficient, does not involve complex processing equipment and process, is widely applicable to most conductive filler and silica gel systems, and provides a new design idea for preparing the flexible crack strain sensor.
The foregoing describes specific embodiments of the present invention. It is to be understood that the invention is not limited to the particular embodiments described above, and that various changes and modifications may be made by one skilled in the art within the scope of the claims without affecting the spirit of the invention.
Claims (10)
1. The high-sensitivity and ultra-soft silica gel elastomer strain sensor is characterized by comprising a flexible packaging layer, a crack conducting layer and a flexible substrate layer which are sequentially stacked from top to bottom.
2. The silica gel elastomer strain sensor of claim 1, wherein conductive silver pastes are respectively arranged at two ends of the crack conductive layer, a wire is arranged on the upper surface of each conductive silver paste, and two ends of the crack conductive layer are respectively connected with the wires.
3. The silica gel elastomer strain sensor of claim 1, wherein the crack conductive layer is formed by self-assembly of a conductive filler at a gas-liquid interface under the driving action of volatilization of a solvent, the conductive filler comprises at least one of carbon nanotubes, graphene, mxene, and conductive carbon black, and the solvent comprises isopropanol.
4. The silicone elastomer strain sensor of claim 1, wherein the flexible substrate layer is a silicone elastomer filled with silicone oil, the silicone elastomer being chemically crosslinked by vinyl terminated silicone oil, hydrogenated silicone oil, platinum based Karstedt catalyst; wherein the viscosity of the vinyl-terminated silicone oil is 20000 to 60000cps; the hydrogen content of the hydrogenated silicone oil is 0.2-0.5%, and the viscosity is 200-800 cps; the purity of the platinum-based Karstedt catalyst is 500-5000 ppm; the viscosity of the filled silicone oil is 300-800 cps.
5. The silicone elastomer strain sensor of claim 1, wherein the flexible material used for the flexible encapsulation layer comprises at least one of PDMS, PET, silicone, PU, medical tape.
6. A method of manufacturing a highly sensitive, ultra-soft silica gel elastomer strain sensor according to any one of claims 1 to 5, comprising the steps of:
step S1: dispersing conductive filler in isopropanol solvent, adding dispersing auxiliary agent, and obtaining conductive component suspension after ultrasonic dispersion;
step S2: uniformly stirring vinyl-terminated silicone oil and hydrogenated silicone oil to obtain a silica gel prepolymer; adding the silica gel prepolymer into a mixed solvent of silicone oil/cyclohexane, and stirring to obtain a silica gel prepolymer solution;
step S3: pouring the conductive component suspension in the step S1 into the silica gel prepolymer solution in the step S2, adding a platinum-based Karstedt catalyst after stirring, pouring the mixed solution into a mould, and standing to form the conductive silica gel elastomer with an upper-lower layered structure; the upper structure of the conductive silica gel elastomer is a crack conductive layer, and the lower structure of the conductive silica gel elastomer is a flexible substrate layer;
step S4: respectively pouring conductive silver paste into two ends of the crack conductive layer, printing out a wire by taking the conductive silver paste as a raw material, respectively connecting two ends of the crack conductive layer with one end of the wire, and leading out the other end of the wire; and packaging the lead and the crack conducting layer by using a flexible material to obtain the high-sensitivity and ultra-soft silica gel elastomer strain sensor.
7. The method according to claim 6, wherein in step S1, the dispersing aid comprises at least one of water-based surfactants including polyvinylpyrrolidone, sodium dodecylbenzenesulfonate, sodium cholate, and cetylammonium bromide; the dispersing auxiliary accounts for 0.02-0.2 wt% of the isopropanol solvent.
8. The method according to claim 6, wherein the solid content of the conductive component suspension in step S1 is 0.05 to 5wt%.
9. The preparation method according to claim 6, wherein in the step S2, the mass ratio of the vinyl-terminated silicone oil to the hydrogenated silicone oil is 8-15:1, the mixing ratio of the silicone oil and the cyclohexane in the silicone oil/cyclohexane mixed solvent is 6-1.5: 1, the dosage ratio of the silica gel prepolymer to the silicone oil/cyclohexane mixed solvent is 1g: 4-12 ml, and the silicone oil in the mixed solvent of silicone oil/cyclohexane is dimethyl silicone oil.
10. The method according to claim 6, wherein in step S3, the volume ratio of the conductive component suspension to the colloidal silica prepolymer solution is 1 to 3:1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311423268.1A CN117387481A (en) | 2023-10-30 | 2023-10-30 | High-sensitivity and ultra-soft silica gel elastomer strain sensor and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311423268.1A CN117387481A (en) | 2023-10-30 | 2023-10-30 | High-sensitivity and ultra-soft silica gel elastomer strain sensor and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117387481A true CN117387481A (en) | 2024-01-12 |
Family
ID=89437129
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311423268.1A Pending CN117387481A (en) | 2023-10-30 | 2023-10-30 | High-sensitivity and ultra-soft silica gel elastomer strain sensor and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117387481A (en) |
-
2023
- 2023-10-30 CN CN202311423268.1A patent/CN117387481A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108701505B (en) | Stretchable conductor sheet, stretchable conductor sheet having adhesive property, and method for forming wiring composed of stretchable conductor on fabric | |
| US10119045B2 (en) | Electroconductive silver paste | |
| Liu et al. | A high performance self-healing strain sensor with synergetic networks of poly (ɛ-caprolactone) microspheres, graphene and silver nanowires | |
| US10746612B2 (en) | Metal-metal composite ink and methods for forming conductive patterns | |
| Ko et al. | Stretchable conductive adhesives with superior electrical stability as printable interconnects in washable textile electronics | |
| Lin et al. | Superior stretchable conductors by electroless plating of copper on knitted fabrics | |
| CN107881768B (en) | Stretchable strain sensor based on polyurethane fibers and preparation method thereof | |
| Park et al. | Stretchable conductive nanocomposites and their applications in wearable devices | |
| Chen et al. | Self-healing and stretchable conductor based on embedded liquid metal patterns within imprintable dynamic covalent elastomer | |
| TWI684999B (en) | Conductive film | |
| CN110527468B (en) | Preparation and application of force-induced conductive adhesive based on one-dimensional and two-dimensional materials | |
| Zhou et al. | A triple-layer structure flexible sensor based on nano-sintered silver for power electronics with high temperature resistance and high thermal conductivity | |
| Wang et al. | A novel combination of graphene and silver nanowires for entirely stretchable and ultrasensitive strain sensors: Sandwich-based sensing films | |
| CN109338727A (en) | A kind of preparation method of flexible wearable strain transducer | |
| Hosseini et al. | A sensitive and flexible interdigitated capacitive strain gauge based on carbon nanofiber/PANI/silicone rubber nanocomposite for body motion monitoring | |
| Yu et al. | High electrical self-healing flexible strain sensor based on MWCNT-polydimethylsiloxane elastomer with high gauge factor and wide measurement range | |
| JP2018054590A (en) | Elastic capacitor and deformation sensor | |
| CN113008124A (en) | Multi-mode sensor and preparation method thereof | |
| CN117387481A (en) | High-sensitivity and ultra-soft silica gel elastomer strain sensor and preparation method thereof | |
| CN108663154B (en) | Flexible wearable air pressure sensor, preparation method and application thereof | |
| CN116447967A (en) | High-sensitivity and high-linearity collaborative bionic flexible strain sensor and manufacturing method thereof | |
| Mao et al. | A highly stretchable AGNWS@ VPDMS–PMHS conductor exhibiting a stretchability of 800% | |
| CN115931186A (en) | Gradient multilayer flexible piezoresistive sensor and preparation method thereof | |
| CN110863352A (en) | High-tensile flexible strain sensor based on double-component polyurethane wire and preparation method thereof | |
| Mosallaei et al. | Improvements in the electromechanical properties of stretchable interconnects by locally tuning the stiffness |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |