Sweat-Activated, Epidermal Wireless Multimodal Sensor Platform for Real-Time and Continuous Sweat Monitoring  

Abstract

With the growing emphasis on health awareness and the management of physical performance, wearable monitoring technologies have rapidly advanced, becoming key tools for personalized healthcare and non-invasive health monitoring. Among various body fluids, sweat has garnered significant attention due to its easy collection and rich biochemical information, including electrolytes, metabolites, and biomarkers that reflect hydration, electrolyte balance, and metabolic state. However, traditional sweat analysis methods rely on complex laboratory procedures, limiting their practicality for real-time and dynamic monitoring. To address these challenges, we propose a skin-adhesive, multimodal sweat monitoring platform powered by a flexible, eco-friendly sweat-activated battery (SAB). This SAB serves as a transient power source, autonomously activating upon sweat contact and providing a stable voltage output without the need for external batteries or charging modules. The platform integrates a dual-modal sensor array, combining electrochemical and colorimetric detection techniques to simultaneously monitor pH, glucose, and chloride ion (Cl-) concentrations. The electrochemical sensor delivers high-sensitivity continuous signals, while the colorimetric module enables intuitive visual feedback. Additionally, the system incorporates a battery-free near-field communication (NFC) module for low-power data acquisition and wireless transmission, enhancing real-time monitoring and portability. This highly integrated platform demonstrates significant potential for short-term dynamic health monitoring, offering a safe, portable, and energy-autonomous solution for next-generation wearable sensors.

Date of Award	21 Aug 2025
Original language	English
Awarding Institution	City University of Hong Kong
Supervisor	Xinge YU (Supervisor)