Self-powered skin electronics for energy harvesting and healthcare monitoring

Self-powered skin electronics capable of energy harvesting and health monitoring is being regarded as the next-generation wearable system, with broad applications both for academic research of artificial intelligence and clinical practice of healthcare medicine. Demonstrated examples of self-powered skin electronics involves various types of devices, associated with energy conversion from piezoelectricity, triboelectricity, biofuel cell, photovoltaics, and thermoelectricity into electrical power source. These systems are of particular interests because they can intimately conform to the surfaces of skin with great flexibility and stretchability, and serve as wearable electronics. In this context, intrinsically stretchable materials and advanced device designs are in development to establish functional, high-performance interfaces with the skin. This review summarizes the most recent advances in this field, with highlight on constituent materials, device configuration, system functionality and integration methods in the past 5 years. Besides, subsequent section includes the related applications of these electronic platforms, with emphasis on energy harvesting and healthcare for human body and animal models. Toward the end of the article, the challenges and opportunities for self-powered skin electronics are discussed, offering information and research ideas for readers. These advances establish the foundations for self-powered devices in electrical skin interfaces of the future, where these advanced technologies suggest broad relevance to diverse skin-integrated electronics.