Mesh Interconnects for Silicone Embedded Stretchable Silicon Electronics

A process development for stretchable silicon electronics encapsulated in a layer of polydimethylsiloxane is presented. Stretchability is achieved by segmenting the normally rigid silicon substrate into small islands (<2×2 mm²) and connecting these by flexible metal interconnects. The metal interconnects have a mesh shape providing stretchability and improved reliability. The mesh-shaped interconnects have been simulated and measured as free standing before being integrated in the final stretchable system design. PDMS (polydimethylsiloxane) encapsulation using either Elastosil or Sylgard, having good chemical and mechanical resistance, provides protection of the final system but it also helps during fabrication. The fabricated samples (ID array silicon islands with mesh interconnects embedded in Elastosil) have been mechanically and electrically tested and provide reversible stretchability to around 100%.