Small aquatic robots that assemble into reconfigurable structures on the water

MIT researchers developed FloatForm, a system of 21-centimeter-square robotic boats that can assemble into rigid floating structures, separate, and form new configurations with limited central control. Each boat carries thrusters, sensors and magnetic latches, allowing it to move independently and connect with neighboring units.

The project draws inspiration from fire ants, which form rafts through local interactions rather than centralized direction. FloatForm similarly assigns robots a final location through a lightweight central planner, while the robots handle navigation, collision avoidance and responses to disturbances by exchanging position information with immediate neighbors. Because robots move in parallel and planning depends on local neighbors rather than the total fleet size, the approach is intended to scale more efficiently than centralized systems.

In MIT pool experiments, eight robots assembled from random starting positions, formed a target shape, detached, reassembled into another shape, and traveled across the pool as one vessel. These runs took four to eight minutes. Simulations indicated the framework could scale to 64 robots. Across 10 trials, the system completed missions without human intervention 90% of the time with four boats and 70% with eight.

A single servo-driven, origami-inspired auxetic mechanism moves permanent magnets on each side of a boat inward to release or outward to latch. The latch can hold either state without continuing motor power. The boats use four thrusters for omnidirectional movement; stabilizing fins and controller tuning addressed instability in early prototypes.

The researchers note that small boats cannot operate in heavily disturbed water. Future deployments may require stronger latches and GPS or vision sensing. Proposed uses include temporary platforms, emergency docking, offshore inspection, environmental monitoring and adaptive public space on waterways.