Soft matter thin sheet science spans materials with many applications, from biological to technological and beyond. In alignment with the goals of MRSEC IRG2, Anna Gaffney’s research probes how these sheets respond to mechanical forces. By altering the material properties of thin sheets and applying large scale lateral deformations, one can impose and study a range of collapse behaviors. Specifically, their group can tune through out-of-plane and in-plane collapse modes via material composition or temperature. As a 5th year Biophysical Sciences PhD candidate, Anna’s research unites the experimental physical chemistry of Ka Yee Lee’s lab in the Dept of Chemistry and the computational mechanical engineering of Luka Pocivavsek and Nhung Nguyen of the SurgBioMech lab in the Dept of Surgery to form a collaboration that utilizes phase-separated lipid monolayers as a model system for studying the collapse of soft matter thin sheets under compressive forces.

In the past year, she has used finite element analysis (FEA) to identify a hyperelastic material model that reproduces the in-plane collapse morphology of lipid monolayers (observed experimentally via fluorescence microscopy) by inducing shear bands. In the following year, they plan to extend this 2D simulation into the third dimension, to further develop this material model to capture out-of-plane collapse modes. She will also utilize MRSEC AFM facilities to capture nanoscale height and stiffness heterogeneity of lipid monolayers, informing the physical understanding of her material model. While conducting this research, Anna is excited to involve high school student researchers and take part in mentorship and outreach activities within MRSEC.

Malcolm Slutzky was born and raised in New Jersey. He first engaged in soft matter physics research during the spring before his first year of college and has worked with a variety of soft materials, including elastic hydrogel microfibers, viscoelastic oleogels, colloidal fluids, and porous media. Since coming to the University of Chicago two years ago, Malcolm has conducted research in Heinrich Jaeger’s lab, studying the ability of shear-thickening dense suspensions (most notably, oobleck) to solidify and fracture under low-velocity impact.

With his MRSEC fellowship, Malcolm plans to investigate the training capabilities of soft shear-jammed solids. For example, can a dense suspension be prepared in such a way that it is more or less likely to fracture? Is it possible to tailor the stress at which a suspension will fracture, using a mechanical or chemical training protocol? Dense suspensions are typically utilized for impact mitigation purposes, such as in bike helmets and wearable protective gear, so this research has the potential to be of value to the general public, as well as the soft matter community.

To learn more about the MRSEC Graduate Fellowships, including how to apply and future application deadlines, click here.