碳纳米管/聚二甲基硅氧烷复合薄膜的制备及力敏特性研究∗

摘要

With the development of sensors, a study on carbon nanotube composites (CNT) used as force sensing elements is presented in this paper, which consists of carbon nanotubes with polydimethylsiloxane (PDMS) as a matrix. Nanocom-posites of carbon nanotube and polydimethylsiloxane, CNT-PDMS with different filler concentrations have been suc-cessfully prepared via ultrasonic and mixed method. With different density, the electrical characteristics change as a function of the strain. The piezo-resistance and piezo-capacitance properties of these composites have been studied in detail. In our experiment, the gauge factor has reached 40 for piezo-resistance and 70 for piezo-capacitance. It is shown that there is an effective and reliable way, which is to change the density of CNT-PDMS nanocomposites, to set the features to sensing strain and stress for resistance and capacitance of the composites. This nanomaterial has a decent potential in mechanical quantity sensors field.%针对传感器的敏感单元发展需求,提出了一种碳纳米管复合材料.该材料是以碳纳米管作为填充粒子,结合聚二甲基硅氧烷(PDMS)有机基体,采用超声共混方法制备的一种新型传感器敏感元件.详细分析研究了复合材料的制备工艺参数,以及在不同工艺参数下该复合材料的力敏特性.扫描电镜测试表明碳纳米管在PDMS中分散均匀且镶嵌良好.通过对不同体积分数的碳纳米管与PDMS复合材料进行电学性能测试,研究薄膜的“力-电阻”和“力-电容”耦合性能,测试了薄膜结构的力敏效应.计算得到复合薄膜材料的压阻灵敏度因子达到40,压电容灵敏度因子达到70.实验研究表明,通过改变碳纳米管与PDMS的比例,可以很好地调节其电子输运特性以及电阻和电容的应力敏感特性,可以为该类型的力敏材料在不同的力敏传感技术领域提供新的研究思路.