Permeable, Stretchable, and Recyclable Cellulose Aerogel On-Skin Electronics for Dual-Modal Sensing and Personal Healthcare
Shuai Liu, Wenwen Li, Xinyi Wang, Liang Lü, Yue Yao, Shuyu Lai, Yunqi Xu, Junjie Yang, Zhihao Hu, Xinglong Gong, Ken Cham‐Fai Leung, Shouhu Xuan
Abstract
Flexible on-skin electronics present tremendous popularity in intelligent electronic skins (e-skins), healthcare monitoring, and human-machine interfaces. However, the reported e-skins can hardly provide high permeability, good stretchability, and large sensitivity and are limited in long-term stability and efficient recyclability when worn on the human body. Herein, inspired from the human skin, a permeable, stretchable, and recyclable cellulose aerogel-based electronic system is developed by sandwiching a screen-printed silver sensing layer between a biocompatible CNF/HPC/PVA (cellulose nanofiber/hydroxypropyl cellulose/poly(vinyl alcohol)) aerogel hypodermis layer and a permeable polyurethane layer as the epidermis layer. The cellulose aerogel displays a high tensile strength of 1.14 MPa and tensile strain of 43.5% while maintaining good permeability. The cellulose aerogel-based electronics embrace appealing sensing performances with high sensitivity (gauge factor ≈ 238), ultralow detection limit (0.1%), and fast response time (18 ms) under strain stimulus. Owing to the disconnection and reconnection of microcracks in the sensing layer, both strain/humidity sensing and thermal healthcare can be easily achieved. The permeable electronics can be further integrated into an electronic mask for patient-centered healthcare with a power supply system, switching control device, and wireless Bluetooth module. Moreover, the prepared electronic system enables long-term wearing on human skin without skin irritation, and all components of the electronics can be recaptured/reused in water. This material strategy highlights the potential of next-generation on-skin electronics with high permeability and good environmental friendliness.