Skin breathable and stretchable electrode based on square-shaped AgNW bundle mesh with wavy bridges

Stretchable electrodes have been developed using various materials and structures to fabricate skin-attachable healthcare devices. However, the developed stretchable electrodes have complex fabrication issues for commercialization and vapor permeability issues for long-term use on human skin. In this study, a biaxially stretchable and skin-breathable electrode consisting of a silver nanowire bundle embedded in an ultrathin and breathable elastomer matrix is presented. The stretchable electrodes are fabricated based on industrially applicable processes such as spray and bar coating, which enables scalable, low-cost, and continuous production. The silver nanowire bundle is self-aligned in a square-shaped mesh with wavy bridges using liquid-bridge evaporation to enhance the biaxial stretchability of the electrode. The breathable elastomer matrix is prepared by patterning with a uniform microhole array. Owing to these structural merits, the electrode consistently maintains its conductivity for more than 60% stretching and exhibits high skin-breathability to efficiently evaporate water generated from human skin. Thus, the developed electrode has great potential in skin-attachable device applications.