Abstract:
The escalating demand for sustainable, flexible, and miniaturized power sources to energize the expanding ecosystem of wearable electronics, implantable devices, and distributed sensor networks calls for a paradigm shift in energy harvesting technologies. Conventional rigid and brittle materials inherently constrain the integration, flexibility, and functionality in real-world environments. The synergy of mechanical bendability, high electrical conductivity, and fluidic adaptability in gallium-based liquid metals (LMs) is emerging as a key enabler for self-powered flexible electronics. This review outlines an advancement in strategy exploiting the unique properties of liquid metals to reshape flexible energy harvesting and realize truly self-powered systems. A comprehensive review of the fabrication of stretchable and reconfigurable LM electrodes, their integration with elastomeric matrices, is discussed with their roles in harvesting biomechanical, vibrational, electromagnetic, and photon energies towards autonomous and flexible electronics. Additionally, we discuss new versatile LM-enabled architectures that enable straightforward integration into sophisticated, curvilinear geometries, demonstrating autonomous, self-powered devices in the form of epidermal sensors, human-machine interface, e-skin, e-textiles, the Internet of Things (IoT), and environmental and infrastructural monitoring. This study not only presents a multifaceted material platform for flexible energy harvesting with high performance, but it also lays a basis for a new class of robust, conformable, and truly self-powered electronic systems instrumental to the future of ubiquitous sensing and human-machine interaction.
