Wearable electronics, conformable sensors, and soft/micro-robotics require conductive yet stretchable thin films. However, traditional free standing metallic thin films are often brittle, inextensible, and must be processed in strict environments. This limits implementation into soft technologies where high electrical conductivity must be achieved while maintaining high compliance and conformability. Here we show a liquid metal elastomeric thin film (LET) composite with elastomer-like compliance (modulus < 500 kPa) and stretchability (>700%) with metallic conductivity (sheet resistance < 0.1 Ω/□). These 30–70 m thin films are highly conformable, free standing, and display a unique Janus microstructure, where a fully conductive activated side is accompanied with an opposite insulated face. LETs display exceptional electro-mechanical characteristics, with a highly linear strain-resistance relationship beyond 700% deformation while maintaining a low resistance. We demonstrate the multifunctionality of LETs for soft technologies by leveraging the unique combination of high compliance and electrical conductivity with transfer capabilities for strain sensing on soft materials, as compliant electrodes in a dielectric elastomeric actuator, and as resistive heaters for a liquid crystal elastomer.

可穿戴电子设备，合适的传感器以及软/微型机器人需要导电但可拉伸的薄膜。然而，传统的独立式金属薄膜通常是脆性的，不可延展的，并且必须在严格的环境中进行处理。这将实施限制在必须保持高顺应性和顺应性的同时必须实现高电导率的软技术中。在这里，我们显示了一种液态金属弹性体薄膜（LET）复合材料，具有类似弹性体的柔度（模量<500 kPa）和可拉伸性（> 700％），具有金属导电性（薄层电阻<0.1Ω/□）。这30–70m个薄膜具有高度的贴合性，独立性，并显示出独特的Janus微结构，其中完全导电的活化面带有相反的绝缘面。LETs具有出色的机电特性，在保持低电阻的同时，变形率超过700％时具有高度线性的应变-电阻关系。我们通过利用高柔顺性和导电性与传递能力的独特组合来证明LETs在软技术方面的多功能性，该传递能力可用于软材料上的应变传感，作为介电弹性体致动器中的顺应性电极以及液晶弹性体的电阻加热器。