Advances in engineering room temperature liquid metal/fiber composites and systems

Abstract

Room temperature liquid metals (LMs), which exhibit excellent electrical conductivity and fluidity, have attracted widespread attention and have immense potentials in the development of stretchable electronics and soft robotics. An important strategy to compensate for the physicochemical-property limitations of pure LMs is integrating the characteristics of fiber materials into LMs. Fibers with high surface-to-volume ratios possess excellent properties, including high flexibility, stretchability, and wear-resistance, as well as a low cost, and are widely used in various industrial fields. The compatibility between pure LMs and fiber materials makes it possible to fully exploit the advantages of both materials, while compensating for their shortcomings. This review focuses on three crucial strategies for forming liquid metal/fiber (LMF) composites or systems by integrating advantages and unique properties of natural and artificial fibers into LMs: (1) reconstruction of the material composition and fabrication of LMF composite materials, (2) the use of fiber-like geometries for LMs, and (3) combining of LM and fiber components or devices to build complex systems. For each strategy, a broad range of applications in various fields, including actuators, sensors, batteries, optics, and wearable electronics, are presented in detail. A comprehensive summary of state-of-the art LMF composite systems is presented, along with the future challenges. This summary is expected to provide new ideas and inspiration for future breakthroughs in this field and promote the innovation and advancement of flexible electronics.