Flexible Wearable Electronics: A Wide Spectrum of Test Techniques

Starting with uniaxial stretch, bend, fold, and twist test techniques, I will discuss some of the innovative multi-axial test techniques that are under development in our lab. I will present how these test techniques with their in-situ capabilities can be adapted to complex surfaces associated with, for example, the human body, aerospace, and automotive structures, food and pharmaceutical items, energy harvesting and storage elements, entertainment and communication devices, and other internet-of-things. I will also discuss how the reliability assessment and accelerated test protocols, established for rigid electronics, need to be re-examined for flexible electronics, as the failure modes in flexible electronics are different. I will conclude the talk by providing specific case studies for flexible and wearable electronics where innovative characterization techniques and new test protocols are necessary. Selected physics-based computational models, as well as failure analysis images, will be presented to provide additional insight.