Mechanically Robust and Healable Transparent Electrode Fabricated via Vapor-Assisted Solution Process

A mechanically robust, transparent, and healable electrode was successfully developed by embedding Ag nanowireg (AgNWs) on the surface of polydimethylsiloxane-based polyurethane (PDMS-CPU) cross-linked by Diels-Alder (DA) adducts. The reversibility of the DA reaction enabled the heated dimethylformamide (DMF) vapor to induce de-cross-linking of the PDMS-CPU preformed as a substrate. A combination of the retro-DA reaction and the plasticizer effect softened the polymer surface, embedding the coated AgNWs on the surface of the polymer. With this simple postprocessing, the surface roughness and mechanical stability of the electrode were largely enhanced. Even with a 55 mu m bending radius, which corresponds to a strain of 90%, the resistance of the electrode after 10 min of vapor treatment increased by 2.1% for inward bending and; 5.3% for outward bending. This result shows a great potential of the proposed method, as it can also be used to fabricate various mechanically deformable transparent electrode. Furthermore, swelling of the PDMS-CPU film owing to the DMF vapor facilitated the healing properties of the scratched electrodes.