基于PEDOT∶PSS的高灵敏度宽量程透明聚合物应变传感器

Transparent Polymer Strain Sensor with Highly Sensitivity and Wide Range Based on PEDOT∶PSS

柔性应变传感器通常难以兼具高灵敏度、宽量程以及透明的性能。提出一种导电层为聚(3,4-乙烯二氧基噻吩)-聚(苯乙烯磺酸)(PEDOT∶PSS)的三明治结构聚合物柔性应变传感器,该传感器在兼顾高灵敏度和宽量程的同时具有高透明性。通过旋涂工艺在聚二甲基硅氧烷(PDMS)基底上制备了可拉伸的透明导电聚合物薄膜;基于掩模氧等离子体刻蚀工艺对聚合物薄膜进行了图案化处理;通过拉伸得到表面具有微裂纹的全聚合物柔性应变传感器。微裂纹在应变加载过程中的开合程度对传感器电阻产生影响,进而能够对各种加载应变做出响应。性能测试结果表明,该柔性传感器在30%的应变下依然能稳定输出信号,满足人体动作检测的最大变形需求;在5%~20%的应变范围内,传感器具备线性响应(线性度>0.9922)和高灵敏度系数(GF为10),克服了传统应变片GF(~2)低、量程小和刚度大的局限性;在可见光波长范围(400~800 nm)内,传感器的透光率超过70%。该传感器能够对人体肌肉和关节运动信号进行监测,在医学康复、运动训练以及人机交互等领域展现出应用前景。

Flexible strain sensors are often difficult to achieve the performances of high sensitivity,wide range and transparency simultaneously.A sandwich-structured polymer flexible strain sensor with a conductive layer composed of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)(PEDOT∶PSS)was proposed.This sensor combines high sensitivity and wide range with high transparency.Stretchable transparent conductive polymer films were prepared on a polydimethylsiloxane(PDMS)substrate by spin-coating process.The polymer films were patterned using masked oxygen plasma etching process.A fully polymerized flexible strain sensor with microcracked surface was obtained by stretching.The opening and closing degrees of microcracks during strain loading affects the resistance of sensor,thereby responding to various loading strains.Performance test results show that the flexible sensor can still stably output signals at 30%strain,meeting the maximum deformation requirements for human motion detection.In the strain range of 5%-20%,the sensor has linear response(linearity>0.9922)and high sensitivity coefficient(gage factor(GF)is 10),overcoming the limitations of traditional strain gauges with low GF of~2,small range and high stiffness.Within the visible light wavelength range(400-800 nm),the transmittance of sensor exceeds 70%.This sensor is capable of monitoring of human muscle and joint movement signals,showing application prospects in the fields of medical rehabilitation,sports training and human-computer interaction.