Eutectic Ga-In liquid metal based flexible capacitive pressure sensor

Abstract

A novel flexible pressure sensor has been successfully developed for detecting varying applied pressures. Polydimethylsiloxane (PDMS) and eutectic gallium indium (EGaIn) based liquid metal, as the conductive electrodes, were used to fabricate the sensor. The sensor was designed with four capacitors (C1, C2, C3 and C4) which were formed by overlapping the liquid metal based electrodes. The capability of the fabricated capacitive pressure sensor was investigated by applying varying pressures. A maximum average capacitance change of 10.14%, 11.56%, 11.57% and 11.82% was obtained for C1, C2, C3 and C4 respectively, when pressures were applied from 0.25 MPa to 1.1 MPa. A sensitivity of 0.11%/MPa and correlation coefficient of 0.9875 was obtained for the fabricated pressure sensor. The results thus demonstrated the potential of using liquid metal based electrodes for the development of flexible pressure sensors.