3D printed trichome-inspired permeable bioadhesive for wearable bioelectronics.

Abstract

Wearable bioelectronics that adhere directly to the skin have broad applications. However, achieving optimal breathability remains a significant challenge because of sweat accumulation at the device-skin interface. Conventional approaches, such as porous structures, often limit the functional versatility of wearable bioelectronics. To address this gap, we propose a sweat-removable skin sticker (SRSS) with a hierarchical trichome-inspired channel architecture that rapidly removes sweat from the interface while maintaining robust skin adhesion. The SRSS was fabricated through a hybrid process, in which the trichome-inspired hierarchical microchannel architecture was created by direct ink writing (DIW), enabling the controlled deposition of viscous ink with high structural fidelity. Through the multi-level ribs design, the SRSS demonstrated an effective area-normalized horizontal water removal rate (25.6 ml/cm²/min) significantly higher than the human sweat secretion rate (0.38-2.85 × 10⁻³ ml/cm²/min)-approximately three orders of magnitude. This feature reduces sweat accumulation in wearable bioelectronics, thereby enhancing user comfort. Unlike conventional porous materials, the SRSS relies on channel based adhesive interface design that remains compatible with attached wearable bioelectronics, such as temperature sensors in real time. This work therefore presents a structurally engineered permeable bioadhesive interface for wearable bioelectronics.