4. Molecular movements and manipulations

4.1 Nanomachines

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,...