Copper Nanowire-Based Aerogel with Tunable Pore Structure and Its Application as Flexible Pressure Sensor.

Aerogel is a kind of material with high porosity and low density. However, the research on metal-based aerogel with good conductivity is quite limited, which hinders its usage in electronic devices, such as flexible pressure sensors. In this work, we successfully fabricate copper nanowire (CuNW) based aerogel through a one-pot method, and the dynamics for the assembly of CuNWs into hydrogel is intensively investigated. The "bubble controlled assembly" mechanism is put forward for the first time, according to which tunable pore structures and densities (4.3-7.5 mg cm-3) of the nanowire aerogel is achieved. Subsequently, ultralight flexible pressure sensors with tunable sensitivities (0.02 kPa-1 to 0.7 kPa-1) are fabricated from the Cu NWs aerogels, and the negative correlation behavior of the sensitivity to the density of the aerogel sensors is disclosed systematically. This work provides a versatile strategy for the fabrication of nanowire-based aerogels, which greatly broadens their application potential.