Miniaturization and the Future of Robot Technology
The field of miniaturization is rapidly advancing in various industries, including the realm of robot technology. The trend towards creating ever smaller units is especially prevalent in the medical and pharmaceutical sectors where minuscule robots may soon be able to transport medication to precise locations within the human body. To lay the foundations for the development of these technologies, a team of researchers at Johannes Gutenberg University Mainz (JGU) has taken a new approach by analyzing the behavior of robotic collectives based on the model of active Brownian particles. The team’s findings, published in Science Advances, suggest an alternative route to achieve programmable active matter.
Collective Robotic Units for Complex Tasks
Researchers are exploring new ways to tackle complex tasks on the micro- and nanoscale that individual robots struggle to accomplish. As devices and components reach the physical limits of miniaturization, one potential solution is to use collectives of robotic units instead of single robots. “The small size of a microrobot places limitations on its task-solving capabilities,” explains Professor Thomas Speck, who led the study at Mainz University. “However, a collective of these robots working together could successfully carry out complex assignments.” Statistical physics, which analyzes models to describe emergent collective behavior, becomes relevant in understanding how these robot collectives interact, similar to how birds flock together.
The research team studied the collective behavior of commercially available walkers, small robots propelled by internal vibrations transmitted to tiny legs. Each robot has slightly different leg characteristics, resulting in circular orbits with unique radii. Resembling little beetles, these robots change direction when they collide with one another.
“Our goal was to analyze and describe the collective behavior of these robots and explore potential applications,” explains Frank Siebers, the lead author of the study. “As physicists, we were also interested in understanding the underlying phenomena.” The researchers observed two effects when the collective of robots had variations in their orbits, indicating greater diversity. Firstly, the robots required less time to explore their environment. Secondly, when confined within a space, they displayed a self-organized sorting behavior. Depending on their orbital radius, the robots either accumulated at the walls of the container or clustered together in the interior.
Insights from Statistical Physics
This collective behavior of robotic units holds implications for various practical applications. For example, exploiting this behavior could enhance the speed at which robots transport and interact with payloads. Professor Thomas Speck suggests that “by utilizing statistical physics, we can uncover new strategies for collectives of robots.”
The field of active matter models and robotics encompasses both living and nonliving systems, where collective behavior or movement can be observed. One well-known example is the coordinated movement of bird flocks. “In this study, we applied the theory underlying our understanding of clustering and swarming to robotic systems,” says Frank Siebers of JGU.
The research was funded through the Collaborative Research Center/TRR 146 on Multiscale Simulation Methods for Soft Matter Systems, a collaborative project involving Johannes Gutenberg University Mainz, TU Darmstadt, and the Max Planck Institute for Polymer Research. The conclusions drawn by the researchers were based on experimental outcomes and model computations performed on JGU’s supercomputer, MOGON II. Principal investigator Professor Thomas Speck held a professorship at the JGU Institute of Physics from 2013 to 2022 and now leads the Institute for Theoretical Physics IV at the University of Stuttgart.