The research objective of this grant is to elucidate failure mechanisms of solvent-filled thin films for use in micro-patterning applications. Solvent-filled thin film systems such as sol-gels are frequently vulnerable to cracking during the drying process, and failure is difficult to predict due to evolving film mechanical properties. In this study, failure criteria will be determined via two non-contact experimental methods specifically tailored towards ultra thin film studies: laser spallation adhesion tests and fluorescence-based digital image correlation measurements. Experimental results will then provide the input data for a finite-element model to predict failure characteristics for more complicated loading regimes.
A mechanics-based analysis for predicting failure onset for solvent-filled thin film systems will provide valuable information to the multiple disciplines that utilize microfabrication techniques. In particular, this work will improve reliability assessment and failure prediction for industrial spray coating applications. Additionally, the ability to control thin film crack formation, width, and density will provide the foundation for a potentially transformative micro-patterning method, offering a low-cost technique for creating hierarchically distributed micro-scale networks. In addition to providing educational development opportunities for both graduate and undergraduate students through intensive research experiences, this work will be integrated into a module for the INSPIRE Program at the University of Louisville, an established summer enrichment program for local high school students targeted towards groups currently unrepresented in engineering.