High-sensitivity large-strain flexible strain sensor and preparation method thereof

A strain sensor and high-sensitivity technology, applied in the direction of electric/magnetic solid deformation measurement, electromagnetic measurement devices, etc., can solve the problems of no more than 2%, difficult balance, etc., and achieve the effects of improving conductivity, increasing effective volume, and high sensitivity

Active Publication Date: 2020-01-14
NANJING UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Sensitivity and strain sensing range are two contradictory properties. For example, a strain sensor based on graphene film has high sensitivity, but its strain sensing range does not exceed 2%, and another strain sensor based on graphene fiber The strain sensing range of the strain sensor can reach 100%, but its sensitivity coefficient does not exceed 10 (GF=(R-R0) / R0Δε, where R represents the resistance before deformation, R0 represents the resistance after deformation, and Δε represents strain)), it is difficult to Balance performance between sensitivity and strain sensing range

Method used

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  • High-sensitivity large-strain flexible strain sensor and preparation method thereof
  • High-sensitivity large-strain flexible strain sensor and preparation method thereof

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Experimental program
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Effect test

Embodiment 1

[0031] Step 1: Measure 90 mL of concentrated sulfuric acid and 30 mL of concentrated nitric acid solution, stir evenly in a 1000 mL beaker to obtain an acid solution; then weigh 0.2 g of multi-walled carbon nanotubes and slowly add them to the acidic mixed solution while stirring , and then stirred at 60 °C for 4 h after the reaction was completed; after the reaction, a large amount of deionized water was added to dilute the obtained solution, and the polyvinylidene fluoride membrane was used for suction filtration. The acidified multi-walled carbon nanotubes can be obtained by drying under vacuum for 48 h; the graphite oxide is prepared by the traditional Hummers method, and then the graphite oxide is placed in water and ultrasonically treated to obtain a monolithic dispersed graphene oxide dispersion. The vinylidene fluoride filter membrane was used for suction filtration. After all suction filtration was completed, the solid was collected and vacuum-dried at 80 °C for 48 h t...

Embodiment 2

[0037] Repeat the method of Example 1 according to the specified components, but in step 1, the mass ratio of concentrated sulfuric acid and concentrated nitric acid is 2:1; in step 2, the ultrasonic power is 50 kHz, and the ultrasonic time is 2 h, and the obtained acidified The concentration of multi-walled carbon nanotubes / graphene oxide suspension was 2 mg / mL; in step 3, the immersion time was 1 h, and the thickness of the obtained multi-walled carbon nanotubes / graphene / carbonized absorbent cotton gauze three-dimensional hybrid network material was 2 nm; in step 4, the elastomer emulsion is styrene-butadiene rubber and natural rubber, the mass ratio is 1:1, the curing temperature is 60 °C, and the curing time is 5 h. The sensitivity index Gaugefactor (GF) of the obtained sensor is about 1375 (0 ε 0 ) / R 0 Δε, where R represents the resistance before deformation, R 0 Indicates the resistance after deformation, and Δε indicates the strain). When the strain is 7.5% and 50%, a...

Embodiment 3

[0039] Repeat the method of Example 1 according to the specified components, but in step 4, the elastomer emulsion is PDMS prepolymer and its curing agent diethylaminomethyltriethoxysilane. The sensitivity index Gaugefactor (GF) of the obtained sensor is about 1285 (0 ε 0 ) / R 0 Δε, where R represents the resistance before deformation, R 0 Indicates the resistance after deformation, and Δε indicates the strain). When the strain is 7.5% and 50%, after repeated 50 times, the sensitivity indexes are 1213 and 7819 respectively.

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Abstract

The invention discloses a high-sensitivity large-strain flexible strain sensor and a preparation method thereof. The method comprises: firstly preparing acidified multi-walled carbon nanotubes, and then ultrasonically preparing acidified multi-walled carbon nanotube/graphene oxide suspension, then taking absorbent cotton gauze as a template, tightly covering the absorbent cotton gauze with acidified multi-walled carbon nanotube/graphene oxide by using a vacuum extraction process, and preparing by using a gradient temperature variation technology to obtain a multi-walled carbon nanotube/graphene/carbonized absorbent cotton gauze three-dimensional hybrid net-like material, and finally compounding and curing with an elastomer emulsion to obtain the high-sensitivity large-strain flexible strain sensor. According to the high-sensitivity and large-strain flexible strain sensor disclosed by the invention, the conditions of the preparation method are mild, the cost is low, the repeatability ishigh, and the strain sensor has excellent deformation capability, is high in sensitivity and wide in strain range, and is used for wearable electronic equipment.

Description

technical field [0001] The invention belongs to the technical field of strain sensor preparation, and in particular relates to a high-sensitivity and large-strain multi-wall carbon nanotube / graphene / carbonized absorbent cotton gauze / elastomer flexible strain sensor and a preparation method thereof. Background technique [0002] In recent years, flexible wearable resistive sensors have received extensive attention from researchers. The strain sensor is a sensor made of "strain-resistance effect", which can convert the local deformation strain on the tested object into an intuitive and measurable resistance change, suitable for health monitoring, virtual electronics, flexible touch screen, human-computer interaction and industrial robots. However, the sensor unit, as the core of wearable devices, faces many challenges. The sensitivity and signal strength of the existing smart sensor units are generally low, and the flexibility and biocompatibility of precious metals commonly ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01B7/16
CPCG01B7/18
Inventor 贾红兵林炎坤张旭敏章婉琪王晶宋万诚陆少杰李雪雨
Owner NANJING UNIV OF SCI & TECH
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