Improving the Sensitivity of Elastic Capacitive Pressure Sensors Using Silver Nanowire Mesh Electrodes

Fully solution-processed elastic capacitive pressure sensors were fabricated by laminating two layers of silver nanowire (AgNW)/polydimethylsiloxane (PDMS) composite films. With Ag-NWs being partly embedded in the PDMS layer to create rough surface, the fabricated sensor device was able to achieve sensitivity three times of that using common metal film electrodes. The mechanism was investigated by comparing sensor devices using the electrodes with different surface roughness and characterizing the microstructure deformation at the surface region of the electrode under pressure using cross-sectional scanning electron microscopy. The devices also present fast response and relaxation (<1 s). It is finally demonstrated that the placement and removal of a small weight leaf (30 mg, corresponding to a pressure of 2 Pa) can be reliably detected by the AgNW mesh electrode sensor devices.