Versatile liquid metal composites constructed by organic-inorganic hybridization strategy for flexible electronics

Abstract

Liquid metal (LM) with high electrical conductivity and fluidity is regarded as promising material for developing multifunctional functional materials. However, the poor interfacial wettability caused by high surface tension of LM and filler agglomeration impedes its applications in flexible electronics. Herein, a facile and cost-effective approach for fabricating LM composites is demonstrated through an organic-inorganic hybridization strategy combined with solvent-assisted dispersion (SAD) technology. Integration of inorganic fillers (e.g., CaCO 3 ) and organic materials (i.e., starch, (polyvinyl alcohol) PVA) into LM enables a 3D solid-liquid bi-continuous conductive network with abundant hydrogen bonds. Notably, LM composites exhibit excellent electrical conductivity (10 6 S/m), which can be processed into as LM chalk, film and conductive coating. Leveraging the excellent malleability, LM-based circuits by direct-writing method can be designed as electrical-heater and smart capacitance sensor. In addition, bulk LM layered composites with biomimetic nacre-like structure exhibit enhanced impact resistance and a flexural modulus of 45 MPa. Furthermore, LM composites can be integrated into actuator with fast response time and wireless communication device. This organic-inorganic hybridization strategy not only extends the fundamental knowledge of LM composites, but also paves a way for constructing multifunctional LM-based electronics, and applicable in soft robotics, wearable electronics and smart sensors.