Date: Wednesday, Jan 24

Time: 15:00-16:00

Location: Lab4, Level E, L4E26

Speaker: Prof. Andres Concha, Adolfo Ibáñez University

Title :  Bioinspired magnetic active matter and the physical limits of magnetotaxis

Abstract:

Magnetotactic bacteria (MTB) are endowed with an exquisite orientation mechanism allowing
them to swim along the geomagnetic  eld lines. This mechanism consists of a chain of bio-synthesized
magnetic nano-crystals that endow MTB with a permanent magnetic moment. Although the physics
behind the minimum size of this biological compass is well understood, it is yet unclear what sets its
maximum size. Here, by using a macroscopic experiment inspired in these microorganisms, we show
that larger magnetic moments will drive the collective behavior of MTB into a phase where bacteria
are unable to swim freely, in detriment of their evolutive  fitness. Simple macroscopic experiments,
numerical simulations, and analytic estimates are used to explain the upper limit for the size of
the chain of nano-crystals in MTB. Our macroscopic bio-inspired experiment, and physical model
provide an exquisite platform to explore the phases of magnetic active matter.