Piezoresistivity of a short fiber/elastomer matrix composite

If the electrical resistance of a material depends upon external straining, the material exhibits 'piezoresistivity'. The piezoresistive behavior has been realized in an electrically conductive elastomer composite where the microstructure of conductive fillers can be changed under finite deformation of elastomer, resulting in the change of the composite resistivity. In this paper, we analyze the piezoresistive behavior of a conductive short fiber/elastomer matrix composite by applying a percolation model. Fiber reorientation model is applied to the composite system with the aim of predicting the relation between the applied finite strain and the reorientation of conductive short fibers. It is found that the piezoresistive behavior of a conductive short fiber/elastomer composite is attributed to the degeneration of initially percolating network under the finite strain. Some numerical results are then compared with our previous experimental data, showing a reasonably good agreement. (C) 1998 Elsevier Science Ltd. All rights reserved.