Fig. 3: Interaction and control of Magbots.

a Effect of the rotation speed and the magnetic binding strength on the coupling and the separation between Magbots. Low rotation speed and strong binding favor the coupling of Magbots, leading to a spontaneous assembly of the swarm. Increasing the rotation speed and/or decreasing the binding strength favors the separation of Magbots (Supplementary Section 1.3.3). b Ideal assembly structures of Magbots with different binding symmetries. Twofold, threefold, and sixfold symmetric Magbots, respectively, form chain-like, honeycomb, and close-packed hexagonal (triangular) lattices. c Experimental platform for the interactive light field (Supplementary Section 1.2.2). d Schematic illustration of the interactive light field experiments. The platform is composed of an LED light board, a CCD camera, and a computer control system. The camera captures the light signals from the LED indicators on Magbots, which are processed by the computer to capture the real-time dynamic states (position and velocity information) of the Magbots. The instantaneous state information is utilized to create a real-time complicated dynamic light field that further influences the motion of the Magbots (through their photoresistors)(Supplementary Section 3.4). e Examples for the interactive light field. For the case of single Magbots, the intensity, relative position, shape, and size of the interactive light spots all can change in real time based on the instantaneous state of individual Magbots or their clusters, according to a given algorithm. f The rotation speed of individual Magbots increases with increasing light field intensity (Supplementary Section 1.3.1). g The rotation speed of Magbot clusters decreases with increasing Magbot number in the clusters (Supplementary Section 1.3.1).