Dynamics of Active Colloids

Date

Apr 3, 2019

Time

11:10 AM - 12:10 PM

Speaker

Cecile Cottin-Bizonne

Affiliation

iLM Lyon

Series

TUD Vorlesungsserie - Microswimmers

Language

en

Main Topic

Chemie

Other Topics

Biologie, Physik, Mathematik, Chemie

Host

Juliane Simmchen, Veronika Magdanz, Benjamin Friedrich

Description

The behavior of self-propelled particles, that are intrinsically out of equilibrium, is rather fascinating and opens new questions. Here we study experimentally the dynamics of active colloids: from the behavior at low density up to crowded conditions. Our system is a monolayer of micron-size gold-platinum Janus particles in water. Upon addition of hydrogen peroxide, the colloids become self-propelled due to the different chemical gradient on both sides. If at low density they behave as perfect hot gas, at intermediate densities we observe a new collective phenomena: the formation of clusters. Measuring the aggregation and fragmentation rates we have rationalized the cluster size distribution and fluctuations. In the dense regime, we notice an unexpected non-monotonic behavior as the activity level rises up.

Links

• Microswimmer's lecture series

Last modified: Apr 1, 2019, 10:44:18 AM