Integration of Conductive Nanocomposites and Nanomembranes for High-Performance Stretchable Conductors

Abstract

Stretchable metallic nanocomposites are viable material candidates for high-performance soft biointerfacing electrodes. However, it is still challenging to fabricate a stretchable metallic nanocomposite that features outstanding charge transfer capability and low impedance as well as high conductivity and mechanical stability. Herein, a material strategy for a stretchable conductor that meets such requirements by integrating stretchable conductive nanocomposites with stretchable conductive nanomembranes (NMs) is presented. The silver nanowire (Ag NW) NM fabricated by the float assembly method is integrated with the Ag NW nanocomposite prepared by the drop-casting method. The compactly assembled NWs in the NM maximize conductivity by reinforcing the percolation networks of the nanocomposite. Moreover, the NM lowers impedance by allowing efficient charge transfer to the target tissue through the exposed NWs. After their integration, a high conductivity of ≈35 700 S cm−1 is obtained, and the impedance is decreased by ≈88.9% (at 1000 Hz) in comparison with the original Ag NW-based nanocomposite (i.e., without integration of the NM). The soft bioelectrode using the stretchable conductor successfully records electrograms from the rat heart, recognizes various arrhythmic events, and applies feedback pacing.