School of Mechanical Engineering:Tomer Markovich
SCHOOL OF MECHANICAL ENGINEERING SEMINAR
Wednesday, December 4, 2019 at 14:00
Wolfson Building of Mechanical Engineering, Room 206
Active Matter: `active thermodynamics’ and the dynamics of biopolymer gels
CTBP, Rice University and DAMTP, University of Cambridge
Active materials are composed of many components that can convert energy from its environment (usually in the form of chemical energy) into directed mechanical motion. Time reversal symmetry is thus locally broken, leading to a variety of novel phenomena such as motility induced phase separation, reversal of the Ostwald process and flocking. Examples of active matter are abundant and range from living matter such as bacteria, actomyosin networks and bird flocks to Janus particles, colloidal rollers and macroscale driven chiral rods. Nevertheless, in many cases experiments on active materials exhibit equilibrium like properties (e.g., sedimentation of bacteria). In the first part of the talk I will try to answer the important question: how do we know a system is `active’? And if it is, can we have generic observables as in equilibrium thermodynamics? Can we measure how far it is from equilibrium? In the second part of the talk I will focus on examples of activity in biopolymer gels, such as the cytoskeleton of living cells. I will show some of the effects of active motors with emphasis on chiral motors. The latter does not have a unique hydrodynamic description, which one can utilize to gain access to the microscopic details of the complex motors using macroscopic measurements. I will also discuss non-motor activity and demonstrate how it can result in contractility, e.g., in the process of cell division.
Dr. Tomer Markovich is Postdoctoral Research Associate in the Center for Theoretical and Biological Physics (CTBP) at Rice University working with Professor Fred MacKintosh. He obtained his PhD in Physics at Tel Aviv University under the supervision of Professor David Andelman in 2017. Prior to his current appointment, Tomer was a Blavtanik Postdoctoral Fellow in the Department of Applied Mathematics and Theoretical Physics (DAMTP) at the University of Cambridge working with Professor Michael Cates.