Hydrodynamically driven docking of blocks for 3D fluidic assembly

In this work we develop a method for fluid dynamically driven assembly in three dimensions and demonstrate its applicability to the development of programmable matter. Towards this end, we investigate docking of a single block onto a larger structure using detailed numerical simulations and experiments. Our simulation results show that a block whose degrees of freedom are limited is able to align parallel with the docking site, a necessary condition for successful assembly, whereas an unconfined block could not. Experiments with blocks that were designed with this approach confirmed alignment parallel with the docking site in 97% of trials. To generate alignment in the other two planes, we designed blocks that self-align due to geometric interactions. We also introduced a pulsating flow to increase the probability of aligned assembly. Using this strategy, a 54% successful (fully aligned) assembly rate was achieved.