Molecular movements and manipulations

Recent work on nanomachines has been spectacular, and is in full swing. The aim is to study molecules specially synthesized to perform an electrical and/or mechanical function on the nanometric scale. At this scale, it's very difficult to know and see whether a molecule is sliding or rolling, how fast it's moving, or whether its motion is quantized or not. The very notion of torque in the macroscopic mechanical sense is itself a matter of debate. The realization of basic functions, such as the "on-off" function, or the realization of a "molecular ratchet" enabling displacement and/or rotation in one direction only, are particularly important issues when considering the development of molecular motors. This would, for example, enable magnetic molecules to be rotated,...