Generalized way to make temperature tunable conductor–insulator transition liquid metal composites in a diverse range

Abstract

Liquid materials with the ability to transit between conductor and insulator are of great scientific and practical significance.

Liquid metal nanocomposites

“…Utilizing solid-liquid phase transition of LMs to compress inclusions and induce conductivity have led to development of "electrical switch" controlled by temperature. 39,63 At low temperatures, LM droplets solidify, expand, and compressed against adjacent particles to form a conductive network in the polymer matrix. When the temperature increases, LM droplets shrink and composite show signicantly high electrical resistance like an insulator.…”

“…Unlike mechanical and laser sintering of LM particles, this activation of LM nanodroplets is reversible, but it is restricted to composites with micron-sized LM droplets. 63 Ultrasonication of bulk EGaIn in chloroform-hydrochloric acid with 1 to 0.01 ratio and varied sonication durations forms LM droplets with average particles sizes of 600 nm to 1.28 mm. 64 If these LM micro-/nanodroplets are shear mixed with a low weight fraction (z0.6 wt%) of graphene akes within elastomer medium and press-rolled, robust electrically conductive exible composites can be fabricated.…”

Pervasive liquid metal printed electronics: From concept incubation to industry

“…Further, based on more generalized liquid metal composite strategy ( Chen et al., 2020 ), the liquid metal dispersed into micro-nano droplets can form liquid metal-polymer composites with the polymer ( Chechetka et al., 2017 ; Fassler and Majidi, 2015 ; Krisnadi et al., 2020 ; Li et al., 2018 , 2020 ; Peng et al., 2019 ; Tang et al., 2018 ; Wang et al., 2018b ), and the resulting ink can be flexibly applied to different substrates ( Figure 2 B). But because of the dispersed liquid metal droplets, special treatments to make them conductive are usually necessary, such as laser ( Deng and Cheng, 2019 ; Liu et al., 2018a ), low temperature ( Chen et al., 2019 ; Wang et al., 2019 ), mechanical pressure ( Boley et al., 2015 ; Zhang et al., 2019a ), evaporation ( Li et al., 2019b ), in situ reduction of silver shell ( Zheng et al., 2020 ), and stretch ( Thrasher et al., 2019 ; Xin et al, 2019 ). Along with more inks and printing, liquid metal can be printed into 2D semiconductor ( Lin et al., 2019 ) or applied to directly compose transistor and functional device ( Li et al., 2019a ).…”

Liquid Metal Microparticles Phase Change Medicated Mechanical Destruction for Enhanced Tumor Cryoablation and Dual‐Mode Imaging

“…Although most materials follow the principle of thermal expansion and cold contraction, the gallium and bismuth are recently discovered with abnormal volume expansion ratio, that is, they would expand their volume during the transition from liquid to solid as the temperature dropped. [ 43,44 ]…”