Active Matter Seminar

Speaker: Abby Plummer, Boston University

Title: Shape morphing with swelling hydrogels and expanding foams

Abstract: Materials that increase in size offer intriguing possibilities for shape-morphing applications. Here, we explore two such systems—swelling polyacrylamide hydrogels and expanding polyurethane foams. The hydrogels swell by absorbing water into crosslinked polymer networks. They can therefore be modeled by coupling solvent migration with the deformations of a hyperelastic solid. In contrast, the foams initially behave as liquids with viscosity and volume increasing in time, responding elastically only when close to solidification. We investigate how these expanding materials are sculpted by complex environments with obstacles and trenches.