Mechanical property variation of AgNW/PDMS nanocomposites for fully elastomeric electrodes

Abstract

Soft electronics necessitate the use of elastomeric components that can sustain dynamic mechanical strain for utilization in highly durable, reliable, and wearable applications. Notably, the development of elastomeric electrodes has been of significant interest for both academic and industrial research. High electrical conductivity, low performance discrepancy under various types of mechanical stimuli, and stable repeatability in the influence of dynamic strain cycles are considered to be some of the major prerequisites for the best soft electronics. Thus, a great deal of effort has been devoted to the formation of such elastomeric electrodes via special architecture and structural engineering. Recent remarkable outcomes in elastomeric electrodes have been accomplished by forming nanocomposites with a percolated network of low-dimensional metallic materials and an elastomer. This approach has aided in achieving scalable manufacturing, soluble printing, extreme mechanical stretchability, and low costs. Herein, we report nanocomposites of silver nanowires (AgNWs) and polydimethylsiloxane (PDMS) with different mechanical properties in order to maximize the electrical performance under various types of mechanical stimuli. Owing to the percolated AgNWs embedded in elastomeric PDMS, the resulting elastomeric electrodes can sustain a mechanical strain of up to 50%, while maintaining a resistance that is below 5 Ω/sq. In addition, a moderate increase in the sheet resistance was observed even after 130 k stretch-release cycles. Our AgNW elastomeric electrodes can be used in elastomeric heaters and have led to the successful capture of dynamic electrophysiological human bio-signals.