One-step growth of large-area silicon nanowire fabrics for high-performance multifunctional wearable sensors

Silicon nanowire (SiNW) fabrics are of great interest for fabricating high-performance multifunctional wearable sensors. However, it remains a big challenge to fabricate high-quality SiNW fabrics in a simple and efficient manner. Here we report, for the first time, one-step growth of large-area SiNW fabrics for multifunctional wearable sensors, by using a massive metal-assisted chemical vapor deposition (CVD) method. With bulk Sn as a catalyst source, numerous millimeter-long SiNWs grow and naturally interweave with each other, forming SiNW fabrics over 80 cm² in one experiment. In addition to intrinsic electronic properties of Si materials, the SiNW fabrics also feature high flexibility, good tailorability and light weight, rendering them ideal for fabricating multifunctional wearable sensors. The prototype sensors based on the SiNW fabrics could effectively detect various stimuli including temperature, light, strain and pressure, with outstanding performance among reported multifunctional sensors. We further demonstrate the integration of the prototype sensors onto the body of a robot, enabling its perception to various environmental stimuli. The ability to prepare high-quality SiNW fabrics in a simple and efficient manner will stimulate the development of wearable devices for applications in portable electronics, Internet of Things, health care and robotics.