Development of microcurrent supporter powered by triboelectric nanogenerator

Abstract

This study describes the development of a microcurrent supporter powered by a triboelectric nanogenerator (TENG), designed to be integrated into an ankle supporter. Microcurrent therapy (MCT) is known for promoting tissue repair, reducing pain, and enhancing muscle recovery. However, conventional MCT devices are not suitable for use during exercise due to size and power source constraints. To address this, the authors developed a self-powered, wearable TENG system that harvests biomechanical energy during walking and delivers microcurrent stimulation through the skin via water-soaked conductive sponge electrodes. The TENG structure employs stacked layers of triboelectric films with conductive nonwoven electrodes, achieving peak voltages exceeding 200 V. A tribotronic energy extractor (TEE) was incorporated to regulate and enhance current output to a biologically effective range (50–500 μA), overcoming impedance mismatch between TENG and human skin. Experimental results demonstrated that when the supporter was used with water-soaked sponge electrodes, contact resistance dropped to 0.1–0.5 MΩ, enabling effective current delivery. Muscle stiffness measurements in the gastrocnemius and soleus muscles showed that applying microcurrents via the TENG-supporter system significantly suppressed post-exercise muscle stiffness compared to no current condition, particularly in the gastrocnemius muscle within the first 45 minutes post-exercise. These findings suggest that triboelectric-powered microcurrent delivery systems can be effectively used during physical activity, offering a novel approach to real-time muscle care and recovery.