基于微裂纹的柔性应变传感器

Flexible strain sensor based on microcracks

柔性应变传感器在电子皮肤、健康监测等方面具有潜在应用价值,已经成为当前研究热点,但仍存在成本高,灵敏度或拉伸率低等问题。为了满足低成本、高性能的需求,通过在聚乙烯醇(PVA)/聚丙烯酰胺(PAAm)双网络水凝胶上滴涂银纳米片(AgNFs)和聚3,4—乙烯二氧噻吩—聚苯乙烯磺酸(PEDOT︰PSS)混合材料制备了AgNFs/PEDOT︰PSS—水凝胶柔性应变传感器。采用傅里叶变换红外吸收光谱仪(FTIR)研究水凝胶的化学结构;采用扫描电子显微镜(SEM)观察传感器的微观形貌;利用电子式拉力试验机和数字源表研究传感器的性能。实验结果表明:传感器同时具备较高的灵敏度(应变系数GF为2 819.8)和较宽的拉伸范围(拉伸率ε为200%),并且在拉伸范围内电阻保持良好的线性(线性回归系数R^(2)为0.992),循环拉伸400次传感器稳定性良好,杨氏模量为58~110 kPa;可以用作监测人体运动等生理信号的可穿戴设备,应用前景广阔。

Flexible strain sensor has potential application value in electronic skin,health monitoring,etc.,and has been a research hotspot.However,there are still problems such as high cost,low sensitivity or low stretch rate.In order to meet the demand of low-cost and high-performance of sensors,Ag nanoflakes(AgNFs)and poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate)(PEDOT︰PSS)are dropped onto poly(vinyl alcohol)(PVA)/poly acrylamide(PAAm)double network hydrogel to manufacture flexible strain sensors.The chemical structure of hydrogels is characterized by Fourier transform infrared spectrometry(FTIR).The microtopography of sensors is observed by scanning electron microscope(SEM).The electrical and mechanical properties are studied by electronic universal tensile testing machine and digit precision multimeter.The experimental results show that the AgNFs/PEDOT︰PSS-hydrogel flexible strain sensor has a high sensitivity(gauge factor GF is 2 819.8),a wide strain range(strain ε is 200 %),an excellent linearity(linear regression coefficient R^(2)is 0.992)and a good cycle stability(400 cycles).The Young’s modulus of the sensor is from 58 to 110 kPa.Because of its good performance,the sensor can be applied as a wearable device to monitor physiological signals such as body movement and it has broad application prospects.