Metal‐Like Stretchable Nanocomposite Using Locally‐Bundled Nanowires for Skin‐Mountable Devices

Abstract Stretchable conductive nanocomposites have been intensively studied for wearable bioelectronics. However, development of nanocomposites that simultaneously feature metal‐like conductivity(> 100 000 S cm −1 ) and high stretchability (> 100%) for high‐performance skin‐mountable devices is still extremely challenging. Here a material strategy for such a nanocomposite is presented by using local bundling of silver nanowires stabilized with dual ligands (i.e., 1‐propanethiols and 1‐decanethiols). When the nanocomposite is solidified via solvent evaporation under a highly humid condition, the nanowires in the organic solution are bundled and stabilized. The resulting locally‐bundled nanowires lower contact resistance while maintain their percolation network, leading to high conductivity. Dual ligands of 1‐propanethiol and 1‐decanethiol further boost up the conductivity. As a result, a nanocomposite with both high conductivity of ≈122,120 S cm −1 and high stretchability of ≈200% is obtained. Such superb electrical and mechanical properties are critical for various applications in skin‐like electronics, and herein, a wearable thermo‐stimulation device is demonstrated.