CAREER: Dynamics of Fragile Interfaces

This Faculty Early Career Development (CAREER) grant will develop bio-inspired models and experimental approaches for soft materials used in biomedical devices, such as silicone implants, that in operation require the outer surface of the device to slide against living cells and tissues. Some current designs may induce inflammation by unintentionally increasing friction, with some aggressively-textured soft implants linked to cases of chronic inflammation and even cancers.

This project investigates the dynamics of soft material interfaces guided by the hypothesis that sliding surfaces in nature reduce friction through a delicate balance of fracturing and rapidly re-healing crosslinks between macromolecules in aqueous solutions. This work will develop biomedically-relevant material systems of different polymer network density and structure, with the long-term goal of creating low-friction interfaces for soft biomedical devices.

This project will train undergraduate and graduate students in interdisciplinary research across biology, engineering, mechanics, and physics. These research efforts will be strengthened by engaging students from underrepresented groups through high school outreach activities, including hands-on demonstrations and workshops for local science teachers, undergraduate research opportunities in partnership with minority-serving institutions, and diversity-focused scientific seminars for graduate students and postdoctoral scholars.

These research efforts address a gap in knowledge and understanding of lubricity in soft aqueous gels and biotribology using engineering tools with molecular specificity, materials characterization techniques, and custom-built instrumentation. The specific research objectives are: (1) develop new models of aqueous gel networks that fracture whilst retaining low shear, (2) synthesize new materials and surface architectures based on hydrogels and weak, self-healing crosslinks to test these hypotheses with in situ experiments, and (3) develop reliable, responsive, and resilient biotribological interfaces for multifunctional purposes and (4) design responsible biodegradable materials by exploring degradation properties and behavior for sustainability purposes.

Establishing and demonstrating the utility of fragile interfaces to provide robust protection and lubricity will extend the study of the mechano-dynamics of fragile interfaces into new fields from biology to chemistry, and medicine using solid mechanics tools.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.