Directed light beams are a promising means of control for microscopic agents, whether they are microrobots or phototatic microorganisms such as Volvox and ciliates. Given the simple reactive behaviors common to most microagents, there is likely to be a certain universality in light-beam algorithms that can usefully ‘herd’ such collectives around. Here, we develop three light-beam control algorithms to herd light-sensitive agents around a two-dimensional environment, each making varying assumptions about agent behavioral capacities. We test them with small swarms of Kilobot robots, which are about 3cm in size. These robots are convenient macro-scale demonstrators of possibilities at the micro-scale. The algorithms are tested in simulation and found to achieve the desired herding goals. Waypoint following missions were implemented using single robots and multiple robots to demonstrate more complex trajectories and highlight the effects of multiple robots interacting. One of the algorithms was tested with real robots and is shown to perform well, owing to good robustness to projection inaccuracies. Future swarm engineers could refer to a common toolbox of broadly effective light-based swarm control algorithms, which can be selected according to agent capabilities.

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