Flexible Capacitive Pressure Sensor based on Dielectric Nanocomposite of Porous Polydimethylsiloxane and Zinc Oxide Nanowire

Elastomeric polymer films, owing to their flexibility, chemical resistance, biocompatibility and low cost with ease of fabrication, have became a popular choice of stress-sensitive dielectric layers for flexible and wearable pressure sensors. However, the pressure response of these flat polymer films is rather poor to tiny pressure change, and also insensitive to large applied pressure. Finding a flexible dielectric film that can be operated in a wider pressure range (e.g., from a few Pa to tens or hundreds KPa) remains a crucial challenge.<br/><br/>Toward this task, we propose the polymer-based dielectric nanocomposite based in porous polydimethylsiloxane and zinc oxide nanowire for capacitive pressure sensing. We anticipate that the porous matrix can improve the compressibility of the nano composite film, meanwhile, the incorporated nanowire can increase the dielectric permittivity. Primary results shows that the zinc oxide nanowire-porous polydimethylsiloxane capacitive pressure sensor exhibits an enhanced sensitivity of 21-100 times (in different pressure range) compared with that of flat, pristine polydimethylsiloxane device. Moreover, an ultra-low detection limit of 1 Pa, and remarkable pressure response behavior during 4000 pressing cycles can be archived. To sum up, this proposed strategy may provide broad application prospects in wearable electronics, health monitoring, and intelligent artificial robots/prosthetics.