Wireless battery-free wearable sweat sensor powered by human motion

TLDR

Wireless wearable sweat biosensors promise noninvasive health monitoring, yet their high energy demands make continuous use difficult; harvesting power from human motion is attractive but current harvesters are complex, fragile, and low‑power, limiting their practicality. The authors aim to develop a battery‑free, mass‑producible wearable platform that harvests power from body motion. This platform uses a flexible printed circuit board–based freestanding triboelectric nanogenerator to efficiently convert motion into electrical energy. The engineered FTENG delivers ~416 mW m⁻², enabling a fully battery‑free system that powers multiplexed sweat biosensors and wirelessly transmits data via Bluetooth during on‑body trials.

Abstract

Wireless wearable sweat biosensors have gained huge traction due to their potential for noninvasive health monitoring. As high energy consumption is a crucial challenge in this field, efficient energy harvesting from human motion represents an attractive approach to sustainably power future wearables. Despite intensive research activities, most wearable energy harvesters suffer from complex fabrication procedures, poor robustness, and low power density, making them unsuitable for continuous biosensing. Here, we propose a highly robust, mass-producible, and battery-free wearable platform that efficiently extracts power from body motion through a flexible printed circuit board (FPCB)-based freestanding triboelectric nanogenerator (FTENG). The judiciously engineered FTENG displays a high power output of ~416 mW m-2 Through seamless system integration and efficient power management, we demonstrate a battery-free triboelectrically driven system that is able to power multiplexed sweat biosensors and wirelessly transmit data to the user interfaces through Bluetooth during on-body human trials.