Reliability Assessment Using Electrical and Mechanical Characterization of Stretchable Interconnects on Ultrathin Elastomer for Emerging Flexible Electronics System

Stretchable electronics is one of the emerging technologies that empowers electronic circuits to gracefully adjust to their surroundings by elongating when subjected to external forces. Integrating stretchable interconnects with deformable materials and optimum geometries establishes a path to high-performance stretchable electronics. The amount of stretch and bend that stretchable interconnect can endure while maintaining functionality are critically important parameters. This article aims to illustrate the mechanical impact of the elastomeric substrate on the stretchable interconnect. In the present analysis, polydimethylsiloxane (PDMS) elastomeric substrate is considered. Five different stretchable interconnect structures viz. straight (St), zigzag (Zz), serpentine (Sp), horseshoe (Hs), and rectangle (Rt), are considered. The electrical parameters, viz. resistance (R), inductance (L), and capacitance (C), are extracted for all the considered stretchable interconnects to assess the conductivity of the interconnect under deformation effects. Furthermore, the Manson formulation-based strain life cycle is formulated, and a fatigue cycle test is performed using a finite element analysis (FEAs) based method on ANSYS Workbench, which confirms the mechanical reliability of the considered stretchable interconnects. The signal integrity analysis of the considered interconnects is performed at varying frequencies. Finally, the interconnect models are verified using experimental model results.