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.