Event

Prof. Dr. Markus Baer (PTB BS): Collective dynamics in active fluids: From pattern formation to control of mesoscale turbulence

Veranstalter:in : FB01, Prof. Dr. Claus Lämmerzahl
Ort : Hörsaal H3, Geb. NW1, Otto-Hahn-Allee 1
Beginn : 08. Juni 2023, 16:00 Uhr
Ende : 08. Juni 2023, 17:00 Uhr

Prof. Markus Bär
Physikalisch-Technische Bundesanstalt, Berlin and Braunschweig, and Institute for Theoretical Physics, TU Berlin

Collective dynamics in active fluids: From pattern formation to control of mesoscale turbulence

Active fluids are constituted by a large number of active agents embedded in passive liquid. These agents consume energy in order to move or exert mechanical forces. Examples include self-organising biopolymers like actin in cells as well as suspensions of microswimmers like bacteria or active colloids. The talk surveys a variety of surprising examples of collective dynamics in active fluid from mechano-chemical waves in giant amoeba cells to so-called mesoscale turbulence at low Reynolds number in bacterial suspensions. With the help of corresponding agent-based and continuum models, we were able to show that this mesoscale turbulence is caused by the interplay of active motion, local alignment of swimmers and longer-range hydrodynamic interactions. Control of turbulence, i. e. a transfer into ordered collective swimming, can be achieved by suitable arrays of small periodic obstacles.