Investigating the motion of molecular machines on surfaces by STM: The nanocar and beyond

To build up true molecular machines and understand the mechanics of nanoscale motion and manipulation in molecular system, we have created and investigated a family of molecules based around the concept of the nanocar, which has the rolling wheels made of spherical fullerene or carborane molecules. Assisted by scanning tunneling microscopy (STM), we have successfully characterized and manipulated these molecules. In addition, we have observed the behavior of these systems when thermal energy is applied. These initial studies open a new realm of nano-sized mechanical, chemical, and electrical devices.