Representation of single-molecule nanocars on a flat metallic surface. A National Science Foundation-funded research team led by James Tour of William Marsh Rice University designed and synthesized this class of molecular machines that resemble macroscopic vehicles and are designed to convert energy inputs such as heat, electric fields or light into controlled motion on a surface, ultimately leading to transport of nanocargo.
Designed to be studied at the single-molecule level by scanning probe microscopy (SPM), these so-called nanocars are composed of a chassis connected to wheel-terminated axles. The rotation of the nanocar wheels induces a directional rolling of the nanocars on a surface. C60 fullerene wheel-based nanocars allowed the demonstration of the directional rolling mechanism of a nanocar on a gold surface by scanning tunneling microscopy (STM). Functional nanocars for transporting atoms and molecules and new molecular wheels have also been developed. Complementary single molecule imaging techniques such as STM, atomic force microscopy (AFM), and single molecule fluorescence microscopy, as well as molecular dynamics, have been used to study these nanocars. [Research supported by NSF grant ECCS 07-08765.]
(Date of Image: July 2009)
Credit: James Tour, Rice University