Stretchable and Flexible Snake Skin Patterned Electrodes for Wearable Electronics Inspired by Kirigami Structure

Herein, snake-skin-patterned electrodes, with high versatility and excellent biocompatibility, are developed by combining the Kirigami structure and biomimicry. The snake-skin electrode has excellent stretchability owing to the integration of the Kirigami structure and patterning. The snake skin patterns are optimized through finite element analysis (FEA) simulations to determine the most stretchable pattern structure. Based on the FEA results, we fabricated the optimal pattern on a polyurethane (PU) substrate by sputtering the AgPdCu alloy target. Even at high strains of 30% and 50%, the electrode exhibits much better stretchability compared with the electrode without the snake skin pattern. The best stretchable electrode exhibits a resistance change (Delta R) of less than 1.5 when it is severely stretched at up to 50% strain. Additionally, the dynamic stretching fatigue test, reveals that it exhibits stable conductivity, thus proving the effectiveness of using snake-skin pattern for stretchable electrodes. The bending, rolling, folding and twisting tests confirm that the electrode has outstanding flexibility, too. A wearable temperature sensor with a snake-skin-patterned electrode exhibits stable and highly sensitive temperature sensing properties. In addition, light emitting diodes connected to the stretchable electrode exhibits stable brightness despite severe deformation of the electrodes.