Towards energy-autonomous wearables: Multimodal harvesting technologies and sustainable applications

<p>The integration of wearable electronics into daily life is revolutionizing personalized healthcare, environmental sensing, and human-machine interfaces. The global market for wearable electronics was valued at approximately $70–80 billion in 2023. By 2029, the scale will reach $138.5 billion. However, the reliance on rigid and short-lifespan batteries severely limit their adaptability and sustainability. Self-powered systems capable of harvesting ambient energy from both environmental sources (light and moisture) and human biomechanics (thermal gradients, motion, and biofluids) represent a paradigm shift toward autonomous and eco-friendly wearable devices. This review systematically classifies and compares six key energy harvesting technologies, i.e., solar cells, moisture-enabled/thermoelectric/triboelectric/piezoelectric generators, and biofuel cells, summarizing their working principles and analyze the issues they face when used in wearable devices, such as improving energy output, flexible manufacturing, and mechanical stability. In addition, we focus on three application scenarios: environmental monitoring, human applications, and human-computer interaction, introducing emerging applications spanning such as real-time PM2.5 detection, self-powered cardiac pacemakers, and deep-sea exploration robots, etc., demonstrating how energy autonomy intersects with global sustainability goals. This review provides a roadmap for transforming laboratory innovation into market ready solutions. Ultimately, the convergence of Adv. Mater., Al-driven design, and circular economy principles outlined here will accelerate the development of next-generation wearable electronics that seamlessly adapt to both human and environmental dynamics.</p>