Highly Stretchable Metallic Nanowire Networks Reinforced by the Underlying Randomly Distributed Elastic Polymer Nanofibers via Interfacial Adhesion Improvement.

On-skin electronics require conductive, porous, and stretchable materials for a stable operation with minimal invasiveness to the human body. However, porous elastic conductors that simultaneously achieve high conductivity, good stretchability, and durability are rare owing to the lack of proper design for good adhesion between porous elastic polymer and conductive metallic networks. Here, a simple fabrication approach for porous nanomesh-type elastic conductors is shown by designing a layer-by-layer structure of nanofibers/nanowires (NFs/NWs) via interfacial hydrogen bonding. The as-prepared conductors, consisting of Ag NWs and polyurethane (PU) NFs, simultaneously achieve high conductivity (9190 S cm ), high stretchability (310%), and good durability (82% resistance increase after 1000 cycles of deformation at 70% tensile strain). The direct contact between the Ag NWs enables the high conductivity. The synergistic effect of the layer-by-layer structure and good adhesion between the Ag NWs and the PU NFs enables good mechanical properties. Furthermore, without any adhesive gel/tape, the conductors can be utilized as breathable strain sensors for precise joint motion monitoring, and as breathable sensing electrodes for continuous electrophysiological signal recording.