School of Physics, Soft Condensed Matter & Physics of Living Systems Seminar, Dr. Liheng Cai, University of Virginia

Synthetic rubber and biological hydrogels are dramatically different, but their properties and functions are largely determined by the structure and architecture of their common components polymers. Such a deterministic correlation poses opportunities in the field of polymer physics. In this talk, I will discuss how concepts and knowledge in polymer physics help understand biological questions, which, in turn, inspires the design of new soft materials.

First, I will discuss the biophysical roles of mucus hydrogel in human lung defense. It will be discussed how pathologically relevant biophysical parameters of mucus help understand interactions among mucus, extracellular matrix, and epithelial cells – the three major components of lung defense. Second, inspired by the structure of constituent molecules of mucus, I will show the development of a soft, thermo-reversible, solvent-free rubber with stiffness on the order of 1 kPa. The temperature triggered solid-to-liquid transition enables the elastomers a new class of soft materials for direct-ink-write 3D printing. I will also discuss immediate applications and emerging challenges stimulated by these discoveries.