Exploring human motions for smart wearables: Energy conversion, harvesting and self–powered sensing

The performance and lifespan of wearable electronics are fundamentally constrained by the limitations of conventional batteries. Biomechanical energy harvesting offers a sustainable alternative by converting energy from everyday human activities such as walking, respiration, and heartbeat. This review analyzes energy harvesters tailored to five characteristic motion modes—linear, deformation, vibrational, rotational, and swing—further classified by anatomical excitation sources. Design strategies, material choices, and integration with self-powered sensing systems are systematically discussed. Finally, we highlight emerging directions for next-generation wearables, including bio-conformal architectures, intelligent energy management, and hybrid harvesting approaches, aiming to enable high-efficiency, autonomous, and environmentally adaptive systems.