Fig. 4: Nontransparent flexible/stretchable conductors from electrospun nanofibers.

a Schematic of substrate-free nanomesh conductors. The lamination process of Au nanomesh onto the skin is as follows: first, the Au layer is deposited onto electrospun PVA nanofibers; then, PVA is dissolved by being sprayed with water; final, after the removal of PVA, the nanomesh conductor adheres to the skin. b Picture of a nanomesh conductor attached to a fingertip. Scale bar, 1 mm. c SEM image of a nanomesh conductor after PVA dissolution. Scale bar, 5 µm. c Photographs showing the Au nanomesh adhered to fingers in relaxed and stretched states. d Conductance changes during 10,000 cycles of finger bending (modified from ref. ⁵⁶, copyright 2017 Springer Nature).