Report

Teaser, summary, work performed and final results

Periodic Reporting for period 2 - ASCIR (Active Suspensions with Controlled Interaction Rules)

Teaser

The main scope of this project is to identify rules in interacting particle systems which allow to understand the formation of living matter in swarms, flocks and swirls. Using a novel experimental approch, where such interaction rules can be implemented, we are aiming to...

Summary

The main scope of this project is to identify rules in interacting particle systems which allow to understand the formation of living matter in swarms, flocks and swirls. Using a novel experimental approch, where such interaction rules can be implemented, we are aiming to investigate the conditions of emergent phenomena in experimental systems, i.e. in the presence of thermal noise but also imperfections regarding particle properties (shape, velocity etc.). Apart from a better understanding of communication in living systems, our work might provide useful information regarding minimal interaction rules in microrobotic systems which are considered as future autonomous systems to deliver e.g. drugs or other loads within liquid environments.

Work performed

Within the period covered by the report, we were able to design and fabricate two working experimental setups where the above defined goals can be accomplished. Based on the configuration of nearby particles, were are now able to allocate each particle its individual velocity and (most recently) also alignment, very similar to the response of living systems. Apart from purely viscous liquids, first experiments in viscoelastic fluids, the latter comprising natural environments of many bacteria, were performed.

Final results

Our setup provides a radically novel approach to tailor particle interactions in active colloidal systems. We believe, that this approach can be also transfered and applied to Brownian particles. Rather than imposing interactions based on their physical properties, i.e. surface functionalization, electric charge or magnetic properties, with our setup, we are able to create almost arbitrarily shaped interaction potentials in such systems. Most importantly, those effective potentials must not necessarily isotropic or even reciprocal.