Colonial Architectures for Centimeter-Scale Underwater Robot Swarms

Abstract

Micro underwater robots offer scalable and low-cost access to environments that are difficult to study with conventional vehicles, but severe communication constraints, limited onboard power, and low swimming speed restrict the capability of these miniature systems. Inspired by colonial organisms such as salps and siphonophores, this work explores physically connected swarms of small underwater robots that form larger structures with improved collective performance. We present a modular platform of centimeter-scale robots capable of three-dimensional propulsion, onboard sensing, and autonomous behavior, with magnetic interfaces that enable reversible connections into prescribed morphologies. Experiments demonstrate autonomous assembly and disassembly, quantify the propulsive benefits of chain aggregates, and show that mechanically coupled robots can distribute sensing, actuation, and control across the collective. Results indicate that certain colonial architectures can greatly improve swimming speed, locomotion efficiency, and task performance compared to individual robots, suggesting a path toward more capable centimeter-scale underwater swarms.