Biocompatible, Flexible, and High-Performance Nanowelded Silver Nanowires on Silk Fibroin for Transparent Conducting Electrodes toward Biomemristor Application
Bhavani Prasad Yalagala, Sri Amruthaa Sankaranarayanan, Aravind Kumar Rengan, Siva Rama Krishna Vanjari
Abstract
This paper demonstrates a facile methodology for fusing silver nanowires (AgNWs) at the nanoscale using a simple, cost-effective UV-ozone treatment. The fusing process not only resulted in interesting morphologies but also reduced the sheet resistance from 100 to 15 Ω/sq. The process optimization ensued in the fusion of AgNWs at the edges with different bending angles that lie between 100 and 140°. The mechanism behind the fusing was elucidated primarily using high-resolution transmission electron microscopy analysis. The optimized process was replicated on top of a silk–poly(vinyl)alcohol (S–PVA) composite that is proven to be thermally stable, flexible, transparent, and biocompatible. This unique combination of fused AgNWs on top of S–PVA is a viable, cost-effective, and scalable prototype for flexible transparent conducting electrodes (FTCEs). A flexible biomemristor was fabricated using ZnO nanoparticles as an active layer and gold and AgNWs as top and bottom electrodes, respectively. The fabricated biomemristor on S–PVA exhibited oxygen vacancy-based RS characteristics at a lower set/reset voltage of +0.25 V/–1 V with an excellent ROFF/RON ratio of 3.5 × 103, higher switching endurance of 500 cycles, and stable data retention of greater than 104 seconds. The strategy outlined here provides a simple, facile, and best optimized solution for the preparation of high-performance and biocompatible FTCEs for the next-generation wearable optoelectronic and biomedical devices.