Liquid metals as active triboelectric media: Dynamic soft-matter architectures for adaptive energy harvesting and soft intelligent systems

초록

Liquid-metal-based triboelectric nanogenerators represent a new paradigm in triboelectric energy systems, providing novel ways to overcome the mechanical stiffness, interfacial instability, and restricted flexibility of traditional solid-state triboelectric devices. Unconventional triboelectrification routes that go beyond traditional solid-solid contact electrification models are made possible by liquid metals owing to their inherent fluidity, high electrical conductivity, deformability, and dynamic interfacial chemistry. This review redefines liquid metals as dynamic, reconfigurable triboelectric media that actively govern dynamic regulation of charge generation, redistribution, storage, and dissipation across multi-interfaces (solid, liquid and gas). First, the fundamentals of LM-as triboelectric media are provided, including phase-transition-assisted electrification, electrochemical double-layer coupling, time-dependent charge trapping, and adaptive impedance modulation. Notable LM-TENG designs, including stretchy films, phase-change systems, surface-modified nanocapsules, porous and fibrous frameworks, and gravity-driven self-adaptive structures are outlined. Interfacial engineering techniques, oxidestate management, and structural dynamics are highlighted as key to achieving stable electrical output during substantial deformation, impact, and long-term cycling. Lastly, novel applications of LM-TENGs are discussed, including soft robotics, human-machine interfaces, motion analysis, physiological sensors, and intelligent safety systems. In addition to offering design principles and perspectives for facilitating the development of nextgeneration adaptive, robust, and multifunctional triboelectric technologies, the challenges and prospects for LM-based triboelectric systems are examined.

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