Stretchable, breathable, and washable epidermal electrodes based on microfoam reinforced ultrathin conductive nanocomposites

Stretchable epidermal electronics allow conformal interactions with the human body for emerging applications in wearable health monitoring and therapy. Stretchable devices are commonly constructed on submillimeter-thick elastomer substrates with limited moisture permeability, thereby leading to unpleasant sensations during long-term attachment. Although the ultrathin elastomer membrane may address this problem, the mechanical robustness is essentially lost for direct manipulations and repetitive uses. Here, we report a stretchable, breathable, and washable epidermal electrode of microfoam reinforced ultrathin conductive nanocomposite (MRUCN). The new architecture involves ultrathin conductive silver nanowire nanocomposite features supported on a porous elastomeric microfoam substrate, which exhibits high moisture permeability for pleasant perceptions during epidermal applications. As-prepared epidermal electrodes show excellent electronic conductivity (8440 S·cm⁻¹), high feature resolution (~ 50 μm), decent stretchability, and excellent durability. In addition, the MRUCN retains stable electrical properties during washing to meet the hygiene requirements for repetitive uses. The successful implementation in an integrated electronic patch demonstrates the practical suitability of MRUCN for a broad range of epidermal electronic devices and systems.