Evaluation of Electromechanical Reliability of Flexible and Stretchable Electronics

Flexible and stretchable electronics (FSE) is an emerging technology with immense potential for multidisciplinary applications. Advancements in FSE rely on design optimization, material innovation, and process development. Key features of FSE systems include single- and multilayer conductors with complex geometries and architectures, vertical interconnect accesses, soft, flexible, and rigid multimaterial interfaces, and encapsulation. During routine use, FSE systems experience mechanical stresses such as flexing, stretching, and twisting, necessitating reliability evaluations that simulate realistic stress conditions and accurate assessments of electromechanical behavior. Customized experimental procedures, grounded in fundamental mechanical testing principles, have been developed to address application-specific requirements. This review highlights advances in electromechanical testing methodologies for printed FSE under tensile, bending, and torsional stress conditions, focusing on test coupon design, experimental procedures, and results. Future research should prioritize evaluating the reliability of fully integrated FSE systems, including those developed sustainably, while deepening understanding of the material properties and fundamental physics of failure.