A robust polymer microcable structure for flexible devices

This letter reports a parylene cable structure that can significantly increase the robustness of flexible devices based on a silicon-island structure. In our previous work, it has been observed that the flexible cables connecting silicon islands could experience stress concentration at the edge of the silicon islands and fracture the metal traces. To address this issue, a micro cushion structure based on parylene micro-channels is proposed to minimize the stress concentration. This structure also improves the overall mechanical strength of the cables, and provides a simple method to encapsulate metal traces reliably.