Empowering Human‐Machine Interfaces: Self‐Powered Hydrogel Sensors for Flexible and Intelligent Systems

Abstract Conventional rigid human‐machine interfaces (HMIs) face significant limitations, including mechanical mismatch with human skin and dependence on batteries requiring frequent replacement/recharging, hindering seamless and biocompatible interactions. Self‐powered hydrogel sensors, characterized by properties such as energy autonomy, tunable mechanics, tissue‐like softness, and biocompatibility, have emerged as promising candidates for advancing wearable healthcare, soft robotics, and next‐generation HMIs. However, challenges encompassing long‐term cycle stability, complete energy autonomy, and adaptive smartness need to be addressed for their further development. Therefore, a systematic understanding of the development and current challenges of self‐powered hydrogel sensors as HMIs is of great importance for realizing their full potential in flexible and intelligent interaction paradigms. This paper reviews the development of self‐powered hydrogel HMIs, focusing on performance‐optimizing strategies for diverse requirements, categorization by energy generation mechanisms, key applications with emphasis on artificial intelligence (AI)‐enabled smartness, and their limitations. Finally, the challenges and future opportunities associated with self‐powered hydrogel HMIs are discussed. This review is believed to provide guidelines for advancing next‐generation HMIs that bridge energy autonomy, multimodal sensing, and AI‐enhanced responsiveness, with hydrogel sensors serving as a cornerstone.