A Novel Strategy for Preparing Stretchable and Reliable Biphasic Liquid Metal

• Published in: Advanced functional materials 2019-09, Vol.29 (36), p.n/a
• Main Authors: Wu, Yun‐hui, Deng, Zhi‐fu, Peng, Ze‐fei, Zheng, Rong‐min, Liu, Shu‐qi, Xing, Shu‐ting, Li, Jun‐yun, Huang, De‐qun, Liu, Lan
• Format: Article
• Language: English
• Subjects: biphasic metals; Casting; Chemical reactions; Circuits; conductive patterns; Conductivity; Electronic circuits; Electronics; Gallium; Heat treatment; Intermetallic compounds; Liquid metals; Low level; Materials science; Nickel; Organic chemistry; Solid phases; Solidification; Strategy
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.201903840

Low‐melting liquid metal is a hugely promising material for flexible conductive patterns due to its excellent conductivity and supercompliance, especially low‐cost and environmental liquid processing technology. However, the ever‐present fluidity characteristic greatly limits the stable shape and reliability of prepared liquid metal conductive electronics. Herein, a novel solidification strategy of liquid GaIn alloys by Ni doping and heat treatment is first reported, which can efficiently create a solid phase in the liquid metal and provide an effective solution for practical applications. Particularly, the liquid characteristic is preserved for conveniently fabricating different flexible electronic circuits, and then the solidification is carried out on prepared conductive patterns by heat treatment. The solidification mechanism is revealed by the interface chemical reaction between Ni and GaIn, creating the solid phase of intermetallic compound (Ga4Ni3 and InNi3) during heat treatment. Moreover, a biphasic GaInNi can be obtained by regulating the atomic ratio of gallium, indium, and nickel. As a result, the obtained GaInNi possesses extremely low sheet resistance (15 ± 4.5 to 135 ± 2.5 mΩ sq−1) and the variation of ΔR/R0 exhibits low level (0–2) when strained up to 100%, which offers a promising strategy to prepare stretchable and reliable liquid metal electronics. A novel regulation technique for achieving liquid metal phase state is reported in this work, which is a revolutionary promotion of liquid metal engineering applications, successfully transforming an amorphous GaIn alloy into a biphasic state, while simultaneously having high conductivity, stretchability, long‐term stability, and reliable mechanical performance.