Extreme miniaturization: Molecular-level devices and machines

A device is something invented and constructed for a special purpose, and a machine is a particular type of device in which the component parts can display changes in their relative positions as a result of some external stimulus. Progress of mankind has always been related to the construction of novel devices. Depending on the purpose of its use, a device can be very big or very small. In the last fifty years, progressive miniaturization of the components employed for the construction of devices and machines has resulted in outstanding technological achievements, particularly in the field of information processing. A common prediction is that further progress in miniaturization will not only decrease the size and increase the power of computers, but could also open the way to new technologies in the fields of medicine, environment, energy, and materials.