The effects of contact area on pressure sensing of ionic polymer metal composite sensor with a soft substrate

Ionic polymer metal composite (IPMC) has been extensively studied as a pressure sensor. Nevertheless, few works have focused on the size effects of external loadings on IPMC pressure sensing. Herein, we investigated the effects of contact area on pressure sensing of an IPMC sensor. By placing a soft substrate behind the IPMC, we enlarged the strain zone when IPMC was deformed. A series of experiments were carried out by changing the radius of loading. And the experimental results revealed that the signal generation of IPMC sensor depends on the compression and bending coupling effects, which even performed a reversal from negative to positive (from-0.184 mV to 0.102 mV) with the increase of the radius of loadings (from 1 mm to 4 mm). Combining the compression model and finite element simulation, we calculated the theoretical voltage and quantitatively compared the experimental results, which showed good consistency. It may provide a new and effective way to simplify the measurement of the contact area.