SUMMARY

Flexible hybrid electronics (FHE) is a classification of assemblies that describes rigid component islands bridged by interconnects printed onto compliant polymer substrates. They boast continued performance integrity in cases that require repeated elongation, including repeated stretching. The last 20 years have demonstrated exponential growth in the application of such designs in industries such as healthcare, energy harvesting, and smart home systems, driving the need for high volume, low cost, manufacturing approaches. Screen printing composite materials such as polymers with conductive particle inclusions offers electrical function with stretchability, but the performance limits of these materials have yet to be fully explored. This dissertation investigates the evolution of electrical performance of silver-filled polymer inks subjected to uniaxial strain. A procedure combining uniaxial elongation with in situ electrical and optical measurements is presented. Digital Image Correlation (DIC), and other image processing techniques, are employed to identify strain localizations in printed conductors, and subsequent reduction of cross-section thickness due to necking or cracking. This strain-induced damage is correlated to measured electrical resistance. Pre and post-mortem cross sectioning provide insights into the architecture of printed composite conductors. Profilometry measurements are used to identify limitations of the screen printing process, and subsequent size effects as they relate to failure strain thresholds.