Non-technical Abstract: This project will determine the optimal design parameters for strong, resilient polymeric materials to improve their use in a wide range of applications including as smart structural materials that can heal after failure, as tissue replacements for damaged joints, and as scaffolds for the large-scale manufacture of stem cell cultures. Our study takes advantage of the unique features of protein-based polymers to create materials with enhanced toughness and resiliency. Our results will provide not only optimization criteria, but will establish the relationships between molecular structure and bulk, macroscopic material response. Building such connections between length scales is very important, and will enable other academic and industrial engineers to leverage our work to solve numerous problems in materials science. This study will engage graduate, undergraduate and community college students in materials research, while providing hands on training in state-of-the-art experimental and computational methods. The students and the PI will participate in community outreach events and visits to local elementary schools to advance a public understanding of cutting edge materials science.
This project will enable the improved design of strong, resilient polymeric materials by establishing the relationships between structure and mechanics in adhesive rigid rod polymer networks. We use a model system made of filamentous cellular proteins called microtubules with chemical and mechanical properties we can tightly control. Experimentally, we apply local forces to such networks using focused electromagnetic fields to manipulate microscale particles and we relate particle displacement to understand the local mechanical properties of the gels. Unlike most synthetic systems, protein-based networks are very rigid allowing them to retain an intrinsic memory of their initial, unloaded state. Moreover, protein-based crosslinkers are labile: their bonds break under force but can reform when the force is removed. These unique features increase biomaterial toughness and resiliency, and allow such materials to 'heal', even when they are locally loaded to failure. Through experimentation and simulation, our work will establish the microscopic origins of material response, and will guide the development of bio-inspired materials that are durable, adaptive, and self-healing. Such materials could be used as artificial tissues or as smart structural materials where shock absorption under loading is required. This work will engage graduate, undergraduate and community college students in materials research. The students and the PI will participate in community outreach events at local elementary schools to advance a public understanding of cutting edge materials science and will share our results broadly through publications, conferences, and in-person visits to local schools.
