Armadillo-inspired Micro-foldable Metal Electrode with Negligible Resistance Change under Large Stretchability

Stretchable electrodes are one of the essential building blocks for stretchable electronics. However, most of reported stretchable electrode show considerable conductivity decrease under large strechability. Until now, it is still a big challenge to develop appropriate geometric structures to realize stretchable metal electrodes with negligible conductivity change under large stretchability. Here, inspired by the armadillo, we develop a novel micro-foldable structure on polydimethylsiloxane (PDMS) using a suspended plasma etching method. This novel structure could endow accomplished stretchable electrodes with excellent properties including high metallic conductivity (>40000 S cm-1) at release and stretched state, slight resistance change (13%) at large tensile range (190%), fully-covered conductive area, excellent cyclic operation stability (over 10000 times), and robust interface adhesion strength (>0.28 MPa). These above-mentioned figures of merit are very prominent compared to the reported stretchable gold electrodes, indicating the superiority of this novel micro-foldable structure. Furthermore, these stretchable electrodes show excellent performance in electromyography (EMG) signals detecting, stretchable conducting wires and capacitive stretchable sensors. This work paves a novel and efficient avenue toward stretchable electronics