Development of a thin-film stretchable electrical interconnection technology for biocompatible applications

Stretchable electronics technologies have gained a lot of interest for reasons such as user comfort and reliability. Key aspect in these technologies is the fabrication of stretchable electrical interconnections. These are realized by patterning an intrinsic, non-stretchable gold film into a sequence of horseshoe shapes, acting as “2D” springs when embedded into PDMS. Polyimide is used as a supporting material, successfully enhancing reliability during mechanical loading. This was illustrated by application of various cyclic uni-axial strains to test structures which were fabricated in this technology. A lifetime over 130´000 and 500´000 cycles has been shown at strains of respectively 20% and 10%.