Effects of cyclic load and chemical media on strain sensing behaviors of conductive polymer composites

In this paper, we simulate common use environments of flexible pressure sensor in human healthcare. CB (carbon black)/PP (polypropylene) conductive composites are soaked in solutions of simulated body fluids with different concentrations for a certain predetermined time. Changes in elasticity modulus, hardness, and creep behavior of the composites on micro-scales are detected by using nanoindentation. Stress-strain curves and strain sensing performance under cyclic compressive load after soaking are obtained by a mechanical testing machine and the four-wire resistance instrument.