Epidermis-Inspired\nUltrathin 3D Cellular Sensor Array for Self-Powered Biomedical Monitoring

Abstract

Sensing\ndevices with wearability would open the door to many advanced applications\nincluding soft robotics, artificial intelligence, and healthcare monitoring.\nHere, inspired by the configuration of the human epidermis, we present\na flexible three-dimensional (3D) cellular sensor array (CSA) via\na one-step thermally induced phase separation method. The CSA was\nframed by the 3D cellular electret with caged piezoelectric nanoparticles,\nwhich was ultrathin (80 μm), lightweight, and highly robust.\nFor biomedical sensing, the 3D-CSA holds a decent pressure sensitivity\nup to 0.19 V kPa^–1 with a response time of less\nthan 16 ms. Owing to its rigid structural symmetry, the 3D-CSA could\nbe identically operated from its both sides. It was demonstrated\nto successfully measure the human heartbeat, detect the eyeball motion\nfor sleeping monitoring, and tactile imaging. Mimicking the functionalities\nof the human skin with a self-powered operation feature, the 3D-CSA\nwas expected to represent a substantial advancement in wearable electronics\nfor healthcare.