Pillared carbon@tungsten decorated reduced graphene oxide film for pressure sensors with ultra-wide operation range in motion monitoring

Abstract

Flexible pressure sensors hold great potential in wearable and artificial intelligence devices. The reduced graphene oxide (rGO) film, as a candidate material for flexible pressure sensors, has the advantage of excellent electronic, mechanical and thermal properties along the in-plane direction. Unfortunately, rGO films exhibit non-ideal structural stability and thermal conductivity along the out-of-plane direction, which poses great challenges in engineering applications. In this work, a “bulk-like” model of alternating reduced graphene oxide/pillared carbon (rGO/PC) layers is built and analyzed through Density Functional Theory (DFT) calculations. Then, theoretical modeling is constructed to provide guidance for the design of a mini-sized, light-weight but high-performance pressure sensor. The rGO/PC-based pressure sensor (rGO/PC-PS) shows extraordinary performances, with high sensitivity of 0.41 kPa−1, ultra-wide operation range (2 kPa–1200 kPa), impressively long durability of 10000 cycles and high working frequency. Electrically and thermally conductive tungsten (W) atoms are deposited on the surface of the rGO/PC film, greatly improving the sensitivity of the rGO/PC/W-based pressure sensor (rGO/PC/W-PS) up to 6.03 kPa−1 at 1300 kPa. Moreover, the rGO/PC/W-PS can be used for weight monitoring, temperature conversion, speech recognition and gripping strength visualization, illustrating its great application potential in the fields of biomedicine and human-machine interaction.