The linear response of composite pressure sensors by controlling effective volumetric filler concentration

The linear response is an important characteristic of composite pressure sensors. However, most conductive composites exhibit strong non-linearity near the percolation threshold, following a power-law relationship. Here we investigate the electrical conductivity of polymer-matrix composites across a wide range of filler concentrations. The logistic regression model accurately explains the percolation behavior, enabling the derivation of a linear response near the inflection point. This novel approach leads to the successful development of a composite pressure sensor with linear response. Reliability is ensured by rigorous evaluation using four different combinations of composite materials. Additionally, implementation of a 30×30 pressure sensor array enables the distinction of different hand poses. This work presents a promising advancement in the development of composite pressure sensors with linear response.