Simple robot swarm with magnetic coupling connections can collaboratively accomplish collective tasks

The use of robotic swarms to study the properties of active matter is a common experimental approach. In such studies, robots are often required to possess capabilities in computation, storage, perception, and two-dimensional (2D) movement to execute predefined rules. Under these rules, the swarm can accomplish complex tasks, exhibit rich collective states, or demonstrate intriguing phase transition phenomena. However, this study demonstrates how a swarm of spin robots, which only respond to simple ambient light intensity, can be constructed into a collective system capable of performing practical swarm tasks such as phototactic motion, controllable folding, and object transport through weak coupling interactions between individuals. Furthermore, it is proven that this swarm exhibits strong system fault tolerance. This research aims to demonstrate that, beyond the common design of sophisticated individuals and excellent inter-individual interaction rules, appropriate structural and coupling designs can enable individuals without computational capabilities to generate complex collective behaviors and accomplish diverse swarm tasks through cooperation. This provides a research direction for experimental studies of active matter using robotic systems.