Intelligent nanomechanical devices that operate in an autonomous fashion are of great theoretical and practical interest. Recent successes in building large scale DNA nanostructures, in constructing DNA mechanical devices, and in DNA computing provide a solid foundation for the next step forward: designing autonomous DNA mechanical devices capable of arbitrarily complex behavior. One prototype system towards this goal can be a DNA mechanical device that is capable of universal computation, by mimicking the operation of a universal Turing machine. Building on our prior theoretical designs and a prototype experimental construction of autonomous unidirectional DNA walking devices that move along linear tracks, we present in this paper the design of a nanomechanical DNA device that autonomously mimics the operation of a 2-state 5color universal Turing machine. Our autonomous nanomechanical device, which we call an Autonomous DNA Turing Machine, is thus capable of universal computation and hence complex translational motion which we define as universal translational motion.

Imagine a host of nanoscale DNA robots move autonomously over a microscale DNA nanostructure, each following a programmable route and serving as a nanoparticle and/or an information carrier. The accomplishment of this goal has many applications in nanorobotics, nano-fabrication, nanoelectronics, nano-diagnostics/therapeutics, and nanocomputing. Recent success in constructing large scale DNA nanostructures in a programmable way provides the structural basis to meet the above challenge. The missing link is a DNA walker that can autonomously move along a route programmably embedded in the underlying nanostructure -- existing synthetic DNA mechanical devices only exhibit localized non-extensible motions such as bi-directional rotation, open/close, and contraction/extension, mediated by external environmental changes.