Liquid–Metal‐Superlyophilic and Conductivity–Strain‐Enhancing Scaffold for Permeable Superelastic Conductors

Abstract

Liquid metal (LM) has recently been used as an advanced stretchable material for constructing stretchable and wearable electronics. However, due to the poor wettability of LM and the large dimensional change during stretching, it remains very challenging to obtain a high conductivity with minimum resistance increase over large tensile strains. To address the challenge, an LM‐superlyophilic and stretchable fibrous thin‐film scaffold is reported, on which LM can be readily coated or printed to form permeable superelastic conductors. In contrast to conventional LM‐based conductors where LM particles are filled into an elastic matrix or printed on the surface of an elastic thin film, the LM can quickly infuse into the LM‐superlyophilic scaffold and form bi‐continuous phases. The LM‐superlyophilic scaffold shows unprecedented advantages of an extremely high uptake of the LM and a conductivity‐enhancement characteristic when stretched. As a result, the LM‐based conductor displays and ultrahigh conductivity of 155 900 S cm−1 and a marginal resistance change by only 2.5 fold at 2 500% strain. The conductor also possesses a remarkable durability over a period of 220 000 cycles of stretching tests. The printing of LM onto the LM‐superlyophilic scaffold for the fabrication of various permeable and wearable electronic devices is demonstrated.

Flexible substrates enabled highly integrated patterns with submicron precision toward intrinsically stretchable circuits

“…Liquid metals with the conductivity of metals and the conformability of fluids make them promising candidates for stretchable conductors 41–43 . Nevertheless, liquid metal has low wettability and is difficult to spread on the surface of materials, while it shows better wettability on Ag NPs and easy to prepare patterns 44 . We used liquid metals (eutectic gallium–indium alloy, EGaIn) and assembled Ag NP arrays to fabricate the composite conductive arrays.…”

Recent Progress in Protective Membranes Fabricated via Electrospinning: Advanced Materials, Biomimetic Structures, and Functional Applications

“…Therefore, water vapor‐permeable and waterproof clothing have a wide range of applications in outdoor clothing, medical and health field, precision electronics, and building materials, as shown in Figure . [ 153,154 ]…”

“…Therefore, water vapor-permeable and waterproof clothing have a wide range of applications in outdoor clothing, medical and health field, precision electronics, and building materials, as shown in Figure 12. [153,154] According to the principle and structure of the waterproof and breathable membranes, they are mainly divided into two categories: 1) porous structure-based waterproof and breathable membranes, and 2) non-porous, waterproof, and breathable membranes. Among them, porous structures refer to membranes that usually contains pores with sizes of 0.5-20 µm and owing to the function of these micro/nanopores, the membranes exhibit waterproof and water-vapor-permeable functions.…”

Ultra‐robust stretchable electrode for e‐skin: In situ assembly using a nanofiber scaffold and liquid metal to mimic water‐to‐net interaction

“…This can also be explained by micro-wrinkles, which have been known for mitigating effective strain applied on stretchable devices. 45,46 In addition, the resistance varied by ~12% after the cycles, making the NHSE among the most robust electrodes in recent state-of-theart works 34,36,43,44,[47][48][49][50] (Figure 2E, Movie S1, Tables S1 and S2). Moreover, the normalized electrical resistance changes merely against twisting, bending, and 25 000-bending cycles, as shown in Figure S8.…”