Incorporating Nanoparticles in Porous Foam Templating for Enhanced Sensitivity of Capacitive Pressure Sensors

Abstract

Capacitive pressure sensors based on porous foams have been demonstrated for various biomedical applications (0–10 kPa). Many different methods for fabricating porous foams have been reported. In this work, for the first time, the incorporation of silica nanoparticles are reported into the templating process of porous foams fabricated through a combination of particle and emulsion templating, in order to enhance the formation of smaller microstructures in polydimethylsiloxane foams. The foams are coated with graphene, and pressure sensors developed using these foams showed increased sensitivity, up to 4.08 kPa⁻¹. The incorporation of nanoparticles also improves the linearity of the sensitivity, giving a linear sensitivity for the pressure sensors over a pressure range of 0–6 kPa. Further, these pressure sensors have a low limit of detection of ≈13 Pa. These results indicate that incorporation of suitable nanoparticles in the templating of foams is a promising strategy for developing foam-based pressure sensors with high and linear sensitivity.