(179a) Oriented Freeze-Casting Fabrication of Resilient Copper Nanowire-Based Aerogel As Robust Piezoresistive Sensor

One dimensional (1D) metallic nanowires-based flexible electronics have promising applications in strain and pressure detection. However, current research on piezoresistive materials are often hindered by robust mechanical performance, elastic-responsive conductivity and inefficient scale-up capacity. Here, we demonstrate a multi-scale fabrication strategy for three-dimensional (3D) copper nanowire-based aerogel with cost-effectiveness, directional and structural regulation and stable strain–electrical signal response via oriented freezing technique. Added polyvinyl alcohol binder dramatically enhances free-standing property and mechanical compliance of aerogel via gluing effect. Besides, this effect between nanowire and polyvinyl alcohol has been revealed by molecular dynamics simulations. Oriented aerogel displays far superior spring-back abilities than does non-oriented aerogel and exhibits good compressibility (undergoing a cyclic compression-recovery at 60%strain) and tunable piezo-resistance sensitivity (0.267 to 0.04 kPa^-1). Additionally, van der waals force contributes actively to the gluing effect on nanowire and polymer. The presented strategy opens up a new possibility for mass production of nanowire-based aerogel with ordered pore orientation and remarkable force-sensitive response.