Samuel L. Foley

Physics of Asymmetrically Stressed Lipid Membranes

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Physics Ph.D. Candidate

Theoretical/Computational Soft Matter Biophysics
Advisor: Markus Deserno

Biophysics Group
Department of Physics
Carnegie Mellon University

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I am a graduate student in the biophysics theory group at Carnegie Mellon. In the Deserno group, we investigate the nano-mechanical properties of lipid membranes within the framework of continuum elasticity. We pair pencil-and-paper theory work with coarse-grained molecular dynamics simulations which provide a ripe landscape for testing the limits of currently understood membrane phenomena. Toward this end, we also develop ultra-coarse-grained lipid models which allow us to access the longest length- and time-scales possible within the limitations of computing power, putting biologically relevant system sizes within reach.

A rapidly developing area of membrane biophysics is the study of bilayer asymmetry and its role in membrane structure and function. In the course of my thesis work, I have developed a modification to a widely-used coarse-grained lipid model rendering it capable of simulating bilayers with differing tensions in the two monolayers. We then put this model to work investigating how differential stress alters first-order phase transitions in lipid membranes, shedding light on the recently-discovered "stiffening transition" observed in membrane simulations. I am presently working on how membrane curvature and its associated stresses play into all of this. My anticipated graduation date is May 2023.


samfoley (at) cmu (dot) edu


Foley, S., Varma, M., Hossein, A., & Deserno, M. (2023). Elastic and Thermodynamic Consequences of Lipid Membrane Asymmetry. Emerging Topics in Life Sciences. (DOI) (Email me for a pre-print)

Foley, S., Hossein, A., & Deserno, M. (2022). Fluid-Gel Coexistence in Lipid Membranes under Differential Stress. Biophysical Journal. (DOI) (Preprint) (SI)

Foley, S. & Deserno, M. (2020). Stabilizing Leaflet Asymmetry under Differential Stress in a Highly Coarse-Grained Lipid Membrane Model. Journal of Chemical Theory and Computation. (DOI) (Preprint) (SI)

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