PDMS micro-dewy spider-web-like metal nanofiber films for fabrication of high-performance transparent flexible electrode with improved mechanical strength

Abstract

Research to develop next-generation flexible transparent electrode materials using various nanomaterials is being actively pursued, and nanomaterials with sufficient conductivity and transparency for replacing ITO have been realized. However, because numerous nanomaterials are in contact physically and overlap with each other to form a wide conductive two-dimensional space, the mechanical strength of an electrode film composed of nanomaterials and the adhesion to the substrate are limited significantly. In this study, we develop a new fabrication process for microsized polydimethylsiloxane (PDMS) droplet-coated conductive nanofiber web films to achieve high-performance flexible transparent electrode films. This concept is inspired by the structure of a spider web with dew, and PDMS microdroplets with transparency and elasticity mimicking the dew of a spider web are introduced into the film. These PDMS microdroplets can improve the mechanical strength to maintain the nanofiber web structure, as well as improve adhesion with various substrates and films owing to the excellent adhesive properties of PDMS. In this study, we confirm the superiority of our approach via transparency/conductivity analysis as well as bending, cycle, wind resistance, and immersion tests. Because this approach involves an extremely short process time of less than 5 min as well as inexpensive equipment and materials, it is expected to be widely applied to various next-generation optoelectronic devices such as flexible displays and wearable devices.