Book of Abstracts: Albany 2005
Nanoengineered Robotic Walkers from DNA
Nature provides us with numerous examples of molecular motors that ?walk? in a bipedal fashion. Molecules such as kinesin are vital parts of cell function, and they have already been adapted for nano-engineering applications (1). Such molecules, however, have certain shortcomings in the hands of nano-engineers. They generally only move in one direction, and they typically only stop when they reach the end of their track or else when they run out of fuel. This makes it difficult to direct them along complex paths: e.g., back and forth, pausing at various times, having one walker move while another stays still.
We present a method for building molecular walkers out of DNA. These walkers have been built (2), and an extremely high level of control demonstrated: the rise and fall of each foot is directed by the operator via the addition of various DNA control strands to the solution, and movement both forward and backward can easily be achieved. Further, since the system is based on the recognition of complementary strands of DNA, multiple copies of the system could operate with independent controls -- allowing movement of some walkers while others remain still or move in different directions.
Walking action can be used to generate linear or rotary movement. Potential applications of these systems include ferrying loads; synthesizing structures with wound, wrapped, or braided polymers; and representing outputs of DNA based computations.
A DNA biped, with two beige domains is shown walking along a blue, three-domain footpath. In the central region, individual bases are shown, with complementary strand segments having the same base color. The enlarged view shows two set strands with black phosphate backbones. The left set strand holds the left foot on the left foothold. The right set strand is just approaching the system and will attach the right foot to the rightmost foothold. On the end of each foot a psoralen molecule is shown in red. The psoralen is used to observe the state of the system.
This research supported by NIGMS, ONR, NSF and Nanoscience Technologies, Inc.
References and Footnotes
William B. Sherman
Department of Chemistry