A precisely controlled DNA biped walking device

We present an experimental realization of a molecular walking motor built from DNA. The device consists of a biped and a well-defined track where it walks. Input DNA strands act as a convenient interface to allow precise control of the biped walking forward or backward. Psoralen molecules are attached to the ends of the feet in synthesis. When irradiated, the psoralen molecules cross-link strands covalently, allowing unambiguous determination of the state of the walker.