A solar-powered wearable physiological sensing system with self-sustained energy management: Design and implementation

Abstract

Wearable sensors are essential for continuous physiological monitoring, yet their long-term operation is often limited by power constraints, particularly under high power demands and device miniaturization. To overcome this challenge, this paper presents the design, implementation, and evaluation of a solar-powered wearable physiological sensing system with self-sustained energy management. Flexible solar cells embedded in clothing enable continuous energy harvesting, while an efficient hardware architecture and a staged startup strategy address cold-start issues under zero-energy conditions. Furthermore, an event-driven open-circuit voltage maximum power point tracking control algorithm, specifically designed for micro-scale photovoltaic systems, is integrated into the energy management unit, achieving a tracking accuracy of 99.75 %. Through a synergistic hardware–software co-design, the system ensures sustained positive energy accumulation. It supports four flexible sensor nodes capable of acquiring, transmitting, and visualizing five physiological signals: electrocardiogram, heart rate, blood oxygen saturation, body temperature, and motion status. Experimental results demonstrate that the system maintains a stable 3.3 V output under different solar irradiance and dynamic lighting conditions, enabling reliable self-powered operation of the four flexible sensor nodes. This work offers a promising approach for long-term, autonomous wearable health monitoring and energy optimization.