Interface Integrity in Stretchable Electronics

Abstract

Stretchable electronic devices enable numerous futuristic applications. Typically, these devices consist of a (metal) interconnect system embedded in a stretchable (rubber) matrix. This invokes an apparent stretchability conflict between the interconnect system and the matrix. This conflict is addressed by shaping the interconnects in mechanistic patterns that bend and twist to facilitate global stretchability. Metal-rubber type stretchable electronic systems exhibit catastrophic interface delamination, which is investigated in this research. The fibrillation process occurring at the delamination front of the metal-rubber interface is investigated through in-situ SEM imaging of the progressing delamination front of peel tests of rubber on copper samples. Results show that the interface strength is dependent on the delamination rate and the interface roughness. Additionally, the fibril geometry seems highly dependent on the interface roughness, while being remarkably independent on the delamination- rate.