A Kirigami Concept for Transparent and Stretchable Nanofiber Networks-based Conductors and UV Photodetectors

To meet the increasing demand for wearable electronics today, fabrication of the stretchable devices becomes crucial. In this respect, a stretchable conductor is an essential component for achieving stretchability of the device. Herein, a stretchable and transparent conductor unit, Au-metallized PVP (Au@PVP) nanofiber network on a kirigami-structured PDMS substrate, was newly developed. By a series of comparative studies, the effectiveness of our strategies to the invariant electrical conductivity and high stretchability is convincingly demonstrated. Our stretchable conductor showed high stretchability of 110% without significant change in resistance, ∼50% increase. It also exhibited ∼80% transparency, as well as excellent durability. To point out its applicability, we fabricated a transparent and stretchable photodetector having the same geometry. ZnO nanorod, the 1D transparent metal oxide nanostructure, is used as a sensing material owing to its high sensitivity for UV light and large surface to volume ratio. The resulting device showed outstanding on/off ratio of 1020 at its original state and 440 under 80% strain. Its fast response/reset time, high transparency and stable performance indicate the feasibility of the stretchable and transparent optoelectronic device.