Programmable 3D Stochastic Fluidic Assembly of cm-scale modules

Self-reconfiguring modular robotic systems offer a potential route to achieving programmable matter, i.e. a substance the shape and properties of which can be tuned as required to achieve a variety of tasks. However, most modular robotic system designs rely on deterministic module motions which place significant power, control, and actuation requirements on the individual modules. This leads to relatively large modules and low target structure resolution. Here we experimentally demonstrate an alternative approach based on stochastic assembly, in which modules assemble into target structures in a fluidic tank. This system employs ambient fluid motion for module transportation. Assembly is directed by controlling the fluid flow through an active assembly substrate with an array of valves. Different valving programs are used with feedback from pressure sensors to achieve the completely automated hierarchical assembly of non-planar 3D structures.