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Contact

35 Gilman Hall
Berkeley, CA 94720
Email: maibaum (at) cal.berkeley.edu
Phone: 510.643.7128
Fax: 510.643.1566

Research

Mechanical coupling of the cell membrane with the actin cytoskeleton

The cellular membrane behaves much like a fluid elastic sheet on sufficiently large length scales. In particular, it resists deformations that change the membrane's area and curvature, which results in a ground state that is essentially spherical. However, it is coupled to the actin cytoskeleton that can generate forces and membrane deformations. Together with Phill Geissler and Dan Fletcher, I study the nature of this coupling. We have found that the membrane can play an active role in actin network reorganization.

Large length scale simulations of fluctuating surfaces

Together with Andrea Pasqua, I am developing a new model to simulate fluctuating surfaces such as cellular membranes. We are trying to bridge the gap between current coarse-grained representations of lipid molecules and the continuum description of elastic sheets. Our model allows us to study processes involving cellular membranes over length scales of hundreds of nanometers, and is capable to reproduce the fluctuation behavior or lipid bilayers.

Dynamics of phase transformation processes

Far away from criticality, phase transformation proceeds by nucleation and growth of domains that resemble the new stable phase. Classical nucleation theory (CNT) and kinetic theories of domain dynamics form the basis of our understanding of this process. My research tries to make quantitative connections between these complementary approaches. I am particularly interested in the dynamics of phase transformation near the classical limit of stability, where the classical theories are expected to break down.

Phase separation processes in lipid bilayers

Giant unilamellar vesicles consisting of mixtures of lipids and cholesterol form a convenient platform to study the dynamics of phase separation processes in a two-dimensional fluctuating environment. The presence of deformation modes changes the dynamics of the separation process as compared to bulk mixtures. Furthermore, the coupling of external factors such as membrane-bound actin filaments can influence the resulting separation patterns as well as the transition temperature.

Emergence of slow dynamics in supercooled liquids

A long-standing mystery in the field of condensed matter physics has been the dramatic change in the dynamical behavior of supercooled liquids as they approach the glass transition temperature, while their static properties remain approximately constant. Together with David Chandler and various members of his research group, I have studied this phenomenon using Molecular Dynamics simulations of binary liquid mixtures. The emerging picture from these studies emphasizes the role of dynamical heterogeneities in glass forming systems, which can be faithfully modelled using kinetically constrained lattice models. Please take a look here for a more detailed description of this ongoing effort.

Publications