Direct Bonding of Gold Nanomeshes at Low Temperature for Flexible and Breathable Electronics

Electrospun nanomesh sheets are promising for skin electronics because of their flexibility and breathability. However, device integration technologies must be established to enable their practical application. This study investigated a new method for room-temperature direct bonding of Au-coated nanomeshes for the development of integrated, flexible, and breathable electronics. Conventional cold welding of Au typically requires high pressures (>100 MPa) or surface activation. In contrast, this technique achieved robust Au-Au bonding at an external pressure of approximately 1 MPa. The bond was formed within 3 s and maintained high electrical reliability, with resistance changes remaining within 5% over 8000 bending cycles at a radius of 1 mm. Critically, the process preserved the breathability of the substrate, exhibiting a water vapor transmission rate comparable to that under open-air conditions. This method provides a reliable integration strategy for next-generation on-skin devices.