A novel multifunctional sensor based on rGO-CuxONW-AgNW/PDMS composites for detecting gas and pressure

Flexible electronic skin (e-skin) for mobile health applications urgently requires wearable pressure-gas sensors, which can be used for body motion detection and identification of environmental gas targets. However, applying pressure-gas sensors to e-skin has always faced challenges of high sensitivity, wide detection range, and high stability. Herein, a novel multifunctional pressure-gas sensor was proposed that 2D reduced graphene oxide (rGO) with 1D copper nanowires (CuNWs) and silver nanowires (AgNWs) form 3D porous composite aerogels by self-assembly and in situ oxidation CuNWs convert to CuxO nanowires (CuxONWs), which ensures efficient electron transfer and sufficient gas adsorption sites. Furthermore, the polydimethylsiloxane (PDMS) layer dramatically improved the electro-mechanical properties of the sensing elastomer. The rGO-CuxONW-AgNW/PDMS (GCOAP) sensing elastomer realizes bi-directional resistive response of pressure (falling) and gas (rising), and is capable of fast response (66 ms) to large pressures (1600 kPa) with high sensitivity (1.405 kPa−1) and specific identification of hazardous NH3 gas at room temperature.