拉伸应变下镍包碳纤维填充导电橡胶取向及电阻响应

导电橡胶因其超高的弹性和良好的导电性而在柔性电子材料领域受到广泛关注。受载时导电填料重新排列会产生相应的电阻变化。本研究选取镍包碳纤维（Nickel coated carbon fiber，CF-Ni）填充于基胶聚二甲基硅氧烷（Polydimethylsiloxane，PDMS）中制备导电橡胶。基于MATLAB平台，观察了导电橡胶中CF-Ni纤维的静态分布，并构建了纤维取向率的计算方法；随后施加动态应变载荷，选用3D打印的样品，在拉伸应变下，对其进行了纤维在胶体中取向变化的同步观察。结果表明:CF-Ni纤维沿拉伸应变方向发生偏转，最大偏转角度可达20°； CF-Ni纤维的取向分布及拉伸应变下纤维的偏转会对导电橡胶的电学性能产生影响，在60%的应变量下，CF-Ni/PDMS表面电阻最大变化为600%。导电橡胶电阻对拉伸应变载荷的响应为CF-Ni/PDMS用于制备柔性传感器奠定了基础。 

Orientation and resistivity response of nickel coated carbon fiber filled conductive rubber at tensile strain

Conductive rubber is a kind of key material and widely used in flexible electronics for its high elasticity and good conductivity. The rearrangement of the conductive filler may lead to the corresponding resistance change when the conductive rubber experiences loadings. In this study, the conductive rubber was prepared by filling Ni coated carbon fibers (CF-Ni) in polydimethylsiloxane (PDMS) matrix and the distribution of CF-Ni was observed. The static distribution of CF-Ni fiber filling in conductive rubber was observed and the calculation method of fiber orientation rate was constructed. The 3D printed samples were synchronously observed when the fillings were redistributed in the matrix under tensile loading. The results show that the CF-Ni fiber deflection along the direction of the tensile strain and the maximum deflection angle achieves to 20°. It is found that fiber orientation distribution and fiber deflection will affect the electrical properties of conductive rubber at different tensile strain. The maximum surface resistance variation of CF-Ni/PDMS is 600% with 60% dependent variable. The response of the resistance in CF-Ni/PDMS conductive rubber at different tensile strain builds a foundation for the preparation of flexible sensor.