Abstract
Control of the structure of matter has been a major challenge to humankind for its entire history. The finer the features that that we are able to engineer, the greater the level of control that we have. Here, we summarize progress made in the bottom-up control of structure that is based on the self-assembly of nucleic acids. Nucleic acids are unique among molecular systems in that their intermolecular interactions can be programmed, from the perspectives of both affinity and of structure. Structural DNA nanotechnology has been based on directing the cohesion of branched DNA motifs by the same cohesive interactions used by genetic engineers. As a result, multiply-connected objects, periodic and aperiodic arrays and nanomechanical devices have been produced by these systems. Current experiments are directed at using nucleic acid systems to scaffold the spatial assembly of other species.