Mechanical and electrical testing of encapsulated stretchable substrate interconnect models for emerging flexible electronic systems

Abstract

Flexible electronics (FE) technology incorporates stretchable interconnects to enable devices those conform to irregular surfaces, bend and stretch without sacrificing functionality. These interconnects are crafted of specialized materials and designs those can withstand mechanical deformations with facilitating seamless integration of electronic components. Serpentine structures are widely used in flexible and stretchable interconnect. However, understanding their mechanical properties under different design parameters is crucial for optimal performance and reliability. In this work, through finite element analysis (FEA), the mechanical behaviour of serpentine interconnect structures with varying geometric parameters, along with and without encapsulation layer is novely investigated. The silver (Ag) material is used as conductor, while both substrate and encapsulation layers are formed using polydimethylsiloxane (PDMS). Also, the effect of mesh analysis is performed on the stretching of the considered interconnect models. Further, the Coffin-Mansons law based fatigue cycle test and the conductivity of the interconnect are analyzed. Finally, the simulation results are validated with experimental results. This research provides essential insightful observations on the interplay between design parameters, mechanical and electrical behaviour for the development of robust stretchable interconnect geometry in flexible electronic systems.