Michael E. Cates
University of Cambridge
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Primary Section: 33, Applied Physical Sciences Membership Type:
International Member
(elected 2021)
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Biosketch
Mike Cates is a theoretical physicist working on the statistical mechanics of soft matter. His work has mainly focused on the relationship between the constituent objects (polymers, colloidal particles, surfactant molecules, mesogens…) that comprise a system and its emergent properties, especially flow behavior. Recently he has become interested in active soft matter in which the constituent objects (such as bacteria or autophoretic colloids) continuously convert energy into motion. Cates was born and raised in Bristol, England. He graduated in Physics and Theoretical Physics from the University of Cambridge in 1982 and completed his PhD studies there in 1985. After Postdocs at Exxon Corp. and the University of California at Santa Barbara, he returned to Cambridge, joining the faculty of the Cavendish Laboratory in 1989, before moving in 1995 to the Chair of Natural Philosophy in the University of Edinburgh. He returned to the Department of Applied Mathematics and Theoretical Physics in Cambridge to take up the Lucasian Professorship in 2015. Cates is a Fellow of the Royal Society (London) and the Royal Society of Edinburgh, and a Foreign Member of the US National Academies of both Engineering and of Sciences.
Research Interests
Mike Cates’ research group currently work on numerous topics that include the following. (1) The theoretical rheology of viscoelastic surfactant solutions: here self-assembled polymer-like objects entangle, break and re-form. Cates was the first to combine models of entanglement with reversible breaking in the 1980s, but since then the entanglement theories have moved forward substantially allowing a new generation of models to be developed for the breakable case. (2) The theoretical rheology of dense suspensions: here the work is now focused on the non-Brownian regime, where frictional contacts between particles strongly influence flow behavior and are in turn dependent on the state of stress, causing startling phenomena such as discontinuous shear-thickening. This builds in part on Cates’ earlier work on Brownian suspensions, in which thermal forces keep particles separated. (3) The physics of active matter: Here interacting, self-propelled particles exhibit new types of irreversible collective behavior that are forbidden in thermal equilibrium. Such features include the liquid-vapor phase separation of purely repulsive particles (predicted in 2008), steady-state circulating currents, and characteristic life-cycles for phase-separated clusters and droplets. A recent focus has been on the local entropy production, defined informatically via the statistical probability of forward and backward trajectories, in turn computable from field-theoretic descriptions of active matter by path-integral methods.
