Interconnect Design-Enabled Stretchable Interdigital Electrode Array for Curved Electronics

As wearable and skin-friendly electronic devices become more popular, there is an increasing demand for devices that can smoothly conform to curved surfaces. However, the fabrication of electronic devices that can stretch or compress to fit these curved surfaces without wrinkles is still a challenge to the traditional planar techniques. In this work, we investigate and compare the stretchability and conformability of the “island-bridge” configuration with three different types of interconnects. The serpentine design with appropriate thickness and spacing is found to significantly excel in stretchability and conformability based on both calculations and experimental results. We propose a complete process for fabricating a stretchable interdigital electrode (IDE) array with serpentine interconnects on a polyimide base. These electrodes can sustain their electrical functionality even under 40% strain. Finally, a piezoresistive sensor array is provided on a dome using this stretchable IDE array. The sensor array exhibits outstanding performance both at the individual sensor level and across the array, demonstrating the viability of stretchable serpentine interconnects for curved electronics.