A solar-powered modular wearable sensor network for distributed multi-parameter health monitoring

The development of wearable health monitoring systems is constrained by the limited energy storage of traditional lithium-ion batteries in miniaturized devices. While ambient energy harvesting enables self-powered operation, existing systems lack modular designs, hindering synchronous multi-parameter monitoring and facing trade-offs between energy efficiency and sensor sensitivity. Targeting personalized, scenario‑adaptable sensing, this study develops a solar‑powered modular sensor network to overcome battery and rigidity limitations—enabling rapid, cost‑effective system assembly via flexible modular design, with high-efficiency energy storage (93.5% at 2500 lux). Via a reconfigurable hardware interface with multi-pin multiplexing, it seamlessly incorporates four high-precision sub-modules: posture (posture classification accuracy >99.3%), physiological (SpO₂ and heart rate), GSR (response time <0.1 s), and movement (joint signal resolution 0.125 mV). These sub-modules can be individually combined with the base modules and deployed at specific body locations to form a distributed health monitoring network. Experimental results show an average operating current of 10.48 mA (1.64 mA in sleep mode) under 3.3 V, supporting distributed synchronous acquisition of multi-dimensional biophysical signals. The system has demonstrated functionalities in fall alerting and learning state assessment, achieving stable self-powered operation. While it offers a foundation for a health monitoring platform, its evolution into a high-precision, universal solution for comprehensive use in complex environments is contingent upon further validation with more extensive and diverse real-world data.