Fabrication And Application Of Light-boosting Ultra-sensitive Pressure Sensors Based On Bionic Multiscale Structures

In the past decade,considerable progress has been made on wearable electronic devices including artificial electronic skins（E-skins）.Pressure sensors,as a fundamental part of E-skins,have attracted tremendous attention because of their potential applications in the fields of health monitoring,human-machine interfaces,artificial intelligence,and so on.How to improve pressure-sensing performances especially the sensitivity and the detection limit is of great importance to expand the related applications,while it is still an enormous challenge so far.Herein,we report highly sensitive piezoresistive pressure sensors with bioinspired mulitiscale surface structures and novel light-boosting sensing performances.The bioinspired multiscale surface structures came from millimeter/micro/nanostructures of rose petal surface replicated on PDMS stamps combined with surface wrinkling nanopatterns of PPy films.The multiscale rose petal surface structures combined with surface wrinkling nanopatterns endow the assembled pressure sensors with outstanding pressure-sensing performances,e.g.,an ultrahigh sensitivity(70 k Pa^-1),an ultralow detection limit（0.88 Pa）and a wide pressure detect range（from 0.88 Pa to 32 k Pa）.Benefiting from outstanding comprehensive performances,our pressure sensors have potential applications in pulse vibrations detections,sound recognition and so on.Remarkably,induced by the superior photothermal effect of PPy film,a simple light illumination further enhances the sensitivity to 120 k Pa^-1 and lowers the detection limit to 0.41 Pa.It is highlighted that the induced 70%current increase mainly occurs at the beginning 5s’light illumination,indicative of a fast response of the pressure sensing to light.Furthermore,the pressure sensors exhibit excellent loading/unloading cycling stability under continuous light irradiation and light-cycling stability under multiple light on/off cycling.The last but not least,the flexible light illumination offers unprecedented capabilities to spatiotemporally control any target in multiplexed pressure sensors for optically enhanced/tailorable sensing performances.This light-control strategy coupled with the introduction of multiscale hierarchical structures is expected to design next generation of advanced wearable electronic devices for unprecedented smart applications.