Designed for use in stretchable displays, the new electrodes were demonstrated to operate reliably even under 50% of stretching or when twisted and rolled. The proof of concept consisted of the KIST logo patterned as a transparent ZnS:Cu alternating-current electroluminescent (ACEL) device formed with wavy Ag nanowire-based stretchable electrodes connecting the two sides of the electroluminescent layer, on an elastomeric substrate the size of an A4 paper.
Here the silver nanowires, only tens of nanometers in diameter, are first spread in a random network of straight nanowires on a pre-stretched sheet of polydimethylsiloxane (PDMS). But instead of releasing the strain and buckling or breaking some of the nanowires in the process, the researchers wetted them with solvents (water). This solvent annealing step, as they describe the process in a paper titled «Buckling Instability Control of 1D Nanowire Networks for a Large‐Area Stretchable and Transparent Electrode» published in the journal of Advanced Functional Materials reduces the frictional resistance between the individual nanowires in the nanowire networks as they become wet.
In particular, each silver nanowire can be worked with in water and rearranged into a curved nanowire structure with a large radius of curvature, so that a structure capable of stably stretching can be realized. Since the nanowires do not experience any unstable conditions, there are no nanowire network fractures or nanowire layer peeling.