Playing with Active Matter on ArXiv

One exemplar of the HEXBUGS used in the experiment. (Image by the Authors of the manuscript.)
Playing with Active Matter
Angelo Barona Balda, Aykut Argun, Agnese Callegari, Giovanni Volpe
arXiv: 2209.04168

In the last 20 years, active matter has been a very successful research field, bridging the fundamental physics of nonequilibrium thermodynamics with applications in robotics, biology, and medicine. This field deals with active particles, which, differently from passive Brownian particles, can harness energy to generate complex motions and emerging behaviors. Most active-matter experiments are performed with microscopic particles and require advanced microfabrication and microscopy techniques. Here, we propose some macroscopic experiments with active matter employing commercially available toy robots, i.e., the Hexbugs. We demonstrate how they can be easily modified to perform regular and chiral active Brownian motion. We also show that Hexbugs can interact with passive objects present in their environment and, depending on their shape, set them in motion and rotation. Furthermore, we show that, by introducing obstacles in the environment, we can sort the robots based on their motility and chirality. Finally, we demonstrate the emergence of Casimir-like activity-induced attraction between planar objects in the presence of active particles in the environment.

Angelo Barona Balda defended his Master Thesis on 10 June 2022. Congrats!

Angelo Barona Balda defended his Master thesis in MPCAS at the Chalmers University of Technology on 10 June 2022 at 13:00. Congrats!

Title: Playful Experiments with Macroscopic Active Matter

Active matter is a substance or system composed of individual agents that consume energy. These agents use the energy to vibrate, self-propel, or apply force to their surroundings.

As it is such a strong theoretical resource, professors use active matter as a gateway to introduce students into non-equilibrium research. However, it is difficult to intuitively explain the behavior of microscopic particles. To better visualize it, academics frequently use simulations , both in classrooms and in research.

In this study, we use the HEXBUGS to replicate active matter simulations performed in previous research papers. We create experiments that are didactic, understandable, and easy to reproduce. Through this, we prove that HEXBUGS behave like active particles.

Name of the master programme: MPCAS – Complex Adaptive Systems
Examiner: Giovanni Volpe
Supervisor: Giovanni Volpe, Aykut Argun
Opponent: Noel Hall, Kasper Hall

Place: Origo 5.102
Time: 10 June, 2022, 13:00

Angelo Barona Balda joins the Soft Matter Lab

(Photo by A. Argun.)
Angelo Barona Balda joined the Soft Matter Lab on 10 January 2022.

Angelo is a master student in Complex Adaptive Systems at Chalmers University of Technology.

During his time at the Soft Matter Lab, he will investigate the behaviour of active matter via experiments with toy robots (HEXBUG nano®).