多壁碳纳米管/硅橡胶复合材料压敏元件特性

为研究碳纳米管填充聚合物复合材料的压力敏感特性,将硅橡胶为基体、多壁碳纳米管为填料的复合材料涂覆在印制板基底上,经溶剂挥发成膜,制备出柔顺式复合材料压敏元件。对碳纳米管质量分数1.6%、4.3%、9.3%的元件进行压阻特性测试,在单轴步进压力下实时检测压力和元件电阻。结果表明,压敏元件在0～110N单轴步进压力下表现出正压阻效应,特性曲线的变化区间与碳纳米管质量分数相互对应。提出压阻效应的机理是元件在压力作用下产生变形,导致碳纳米管导电网络发生破坏与重构。扫描电镜分析表明,碳纳米管随机取向分散于硅橡胶基体中,形成1-3型复合结构。该新型复合材料压敏元件可用于开发柔顺式力传感器。

Properties of multi-walled carbon nanotube/silicone rubber composite pressure-sensitive elements

Flexible pressure-sensitive composite elements were fabricated using the solvent volatilizing method to investigate pressure-sensitive characteristics of carbon-nanotube-filled polymer composites.Silicone rubber was used as the matrix with the multi-walled carbon nanotube(MWCNT) used as the filler.The composite was coated onto printed circuit board substrates for forming films.Experiments were carried on elements with the MWCNT mass fraction of 1.6%,4.3% and 9.3% to investigate piezoresistive properties.The elements were compressed under a uniaxial stepped pressure with the pressure and resistance measured in real time.The results indicate that elements demonstrate positive piezoresistive effects under a uniaxial stepped pressure of 0—110 N,and the characteristic plot varies with the MWCNT mass fraction.The mechanism of the piezoresistive effect was explained as the destruction and the reconstruction of conductive MWCNT networks due to the deformation of elements under pressure.Analysis using a scanning electron microscopy(SEM) reveals that MWCNTs are randomly oriented in the silicone rubber matrix with a 1-3 composite structure produced.This type of pressure-sensitive composite element can be used to develop flexible force sensors.