Active matter at work: from Szilard engine, to active polymers and reactive films

Speaker: Paolo Malgaretti (Helmholtz Institute Erlangen-Nürnberg for Renewable Energy, Erlangen, Germany)

Abstract:

Active matter is a peculiar “state” of matter where, via continuous energy consumption, the equilibrium is broken at small length scales. This makes active matter different from standard equilibrium states of matter, which require no energy input, and from driven systems which are typically brought our of equilibrium by acting on the macroscopic scale.

In this seminar I will review some recent results in which we have characterized the active state of colloids, polymers, and thin liquid films. In particular, I will discuss how the active state of colloidal particles can lead to the design of novel information-based engines (similar to Szilard engines) which cannot be attained with passive colloids [1]. Then I will characterize the collective dynamics of active colloids when they form one chains, also called active polymers, and I will show how the interplay of the activity and the conformation of the polymer can lead to counter-intuitive dynamics within porous materials [2,3]. Finally, I will show that a suspension of active colloids can destabilize thin films and deform the shape of droplets [4].

[1] Szilard engines and information-based work extraction for active systems, Physical review letters 129 (22), 228005

[2] Globule-like conformation and enhanced diffusion of active polymers, Physical review letters 121 (21), 217802

[3] Coil-to-globule collapse of active polymers: a Rouse perspective, Molecular Physics 123 (7-8), e2384462

[4] Chemically reactive thin films: dynamics and stability, Advanced Materials Interfaces 12 (9), 2400835

This seminar will take place in room D1.110