This is the type of DNA-based walking machine that will be explored at the new CBC Center for Molecular Cybernetics. The particular walker shown here was actually demonstrated in 2004 by Caltech chemists Jong-Shik Shin and Niles A. Pierce. (J. Am. Chem. Soc, vol. 126, no. 35, 2004.) All the various DNA strands involved in its operation are synthesized artifically. Rising in a vertical double helix are the orange and black strands that form the body and legs of the walker itself. Along the bottom is the multicolored spiral of a DNA-based "track," which also carries a series of green, purple, red and blue "attachment" strands. The motion of the walker is powered by two types of free-floating "fuel" strands, colored yellow and pink, which alternately come in, intertwine with the appropriate leg and attachment strand, and then detach to allow the walker to take the next stride.

Credit: Niles A. Pierce, California Institute of Technology