Symmetrical orientation of spiral-interconnects for high mechanical stability of stretchable electronics

Recently, interconnect based stretchable electronic devices have attained growing interest due to its application for various state-of-the-art technologies. Here, we report an engineered design of spiral interconnects for a series of stretchable networks referred to as the symmetrical series; wherein spirals connect to the island in the symmetry manner. A systematic analysis of Si-based spiral interconnects by numerical modeling, and experiments show that our design provides higher stretchability of 165% in comparison to the conventionally used nonsymmetrical design. The reason for high mechanical reliability is attributed to the favorable unwrapping profile of spiral interconnect due to the nature of forces acting on it during the stretching process. In contrast, for the nonsymmetrical series, the nature of tensile forces produces the rotation, and resultant tilting of spiral arm results in low stretchability of 150%. As a result, nonsymmetrical interconnect fails at earlier stages of stretching. Our study demonstrates the significance of the orientation of spiral interconnects linked to the island to attain the high performance of stretchable electronic devices.