Pacific Institute for the Mathematical Sciences - PIMS

The Swim Pressure of Active Matter

One of the distinguishing features of many living systems is their ability to move, to self-propel, to be active. Through their motion, either voluntarily or involuntarily, living systems are able self-assemble: birds flock, fish school, bacteria swarm, etc. But such behavior is not limited to living systems. Recent advances in colloid chemistry have led to the development of synthetic, nonliving particles that are able to undergo autonomous motion by converting chemical energy into mechanical motion and work – chemical swimming. This swimming or intrinsic activity imparts new behaviors to active matter that distinguish it from equilibrium condensed matter systems. For example, active matter generates its own internal pressure (or stress), which can drive it far from equilibrium and free it from conventional thermodynamic constraints, and by so doing active matter can control and direct its own behavior and that of its surroundings. In this talk I will discuss our recent work on swimmers and on the origin of a new source for stress that is responsible for self-assembly and pattern formation in active matter.

Bio: John Brady is Chevron Professor and Executive of Chemical Engineering at the California Institute of Technology. Previously, professor Brady studied at the University of Pennsylvania (B.S. 1975), and Stanford University (M.S. 1977 and Ph.D. 1981) followed by a postdoctoral fellowship at ESPCI and a faculty position at MIT. He is a member of the National Academy of Engineering (1999), recipient of the Bingham Medal from the Society of Rheology (2007) and the Fluid Dynamics Prize from the American Physical Society (2011) amongst many other awards for his work in fluid mechanics.

Light Reception from 2:30pm - 3:00pm at the PIMS Lounge: ESB 4133

Lecture Room: ESB 2012