Janus Asymmetric Cellulosic Triboelectric Materials Enabled by Gradient Nano‐Doping Strategy

Abstract The rapid development of wearable electronic devices has posed higher demands on the design strategies of advanced sensing materials. Multidimensional functionality and energy self‐sufficiency have consistently been focal points in the field of wearable sensing. The construction of biomimetic nanostructures in sensing materials can endow sensors with intrinsic response characteristics and derivative performance. Here, inspired by the Janus structure and function of human skin, a gradient nano‐doping strategy is proposed for developing cellulosic triboelectric materials with biomimetic‐ordered Janus asymmetric structures. This strategy integrates the complementary advantages of internal components and structures to meet the complex requirements of self‐powered sensing materials. The triboelectric material simultaneously achieves high electrical output power (2.37 W m⁻²), excellent mechanical properties (withstanding tensile forces over 20 080 times its weight), and thermal conductivity. The wearable self‐powered wireless sensing system designed accordingly demonstrates excellent sensitivity (27.3 kPa⁻¹) and sustained performance fidelity (15 000 cycles), faithfully recording human motion training information. This research holds significant research value and practical implications for the material structure, mechanical properties, and application platforms of wearable electronic devices.