Quasi‐Homogeneous and Hierarchical Electronic Textiles with Porosity‐Hydrophilicity Dual‐Gradient for Unidirectional Sweat Transport, Electrophysiological Monitoring, and Body‐Temperature Visualization

Abstract On‐skin electronics based on impermeable elastomers and stacking structures often suffer from inferior sweat‐repelling capabilities and severe mechanical mismatch between sub‐layers employed, which significantly impedes their lengthy wearing comfort and functionality. Herein, inspired by the transpiration system of vascular plants and the water diode phenomenon, a hierarchical nonwoven electronic textile (E‐textile) with multi‐branching microfibers and robust interlayer adhesion is rationally developed. The layer‐by‐layer electro‐airflow spinning method and selective oxygen plasma treatment are utilized to yield a porosity‐hydrophilicity dual‐gradient. The resulting E‐textile shows unidirectional, nonreversible, and anti‐gravity water transporting performance even upon large‐scale stretching (250%), excellent mechanical matching between sub‐layers, as well as a reversible color‐switching ability to visualize body temperature. More importantly, the conducting and skin‐conformal E‐textile demonstrates accurate and stable detecting capability for biomechanical and bioelectrical signals when applied as an on‐skin bioelectrode, including different human activities, electrocardiography, electromyogram, and electrodermal activity signals. Further, the E‐textile can be efficiently implemented in human‐machine interfaces to build a gesture‐controlled dustbin and a smart acousto‐optic alarm. Hence, this hierarchically‐designed E‐textile with integrated functionalities offers a practical and innovative method for designing comfortable and daily applicable on‐skin electronics.