Self-Assemble of Water Floating Active Units

In this paper, a novel model of active floating units which can self-assemble on the water surface is proposed. We focus especially on the shape of the unit, which is an essential factor of aggregation but difficult to deal with existing frameworks. After several experiments, a unique self-assembling behavior was observed by exploiting several physical-level forces; 6 units which have a cake-cut shape gather into a cluster and form a propeller-like pattern, which is unique to the configuration. This kind of hierarchical behavior is considered crucial to achieve morphogenesis of a multi-unit system. The results shown here provide a good starting point for speculation about the level of autonomy of a unit in the complex environment when the system creates a self-assembling pattern.