At the boundary between classical motion and the quantum tunneling effect, a team of researchers from Empa (Swiss Federal Laboratories for Materials Science and Technology) and EPFL (Federal Polytechnic School of Lausanne) have developed a molecular motor consisting of only 16 atoms ( 100,000 times finer than a hair) and turns reliably in one direction.
Less than a nanometer
The motor measures less than a nanometer . Like a large-scale motor, the 16-atom motor consists of a stator and a rotor, that is, a fixed part and a moving part. The rotor rotates on the surface of the stator. It can occupy six different positions.
In the macroscopic world, a ratchet (a mechanism that allows a gear to turn to one side but prevents it from turning the other way) moves up the flat edge and locks in the direction of the steep edge. In contrast, an atomic motor, as it operates at the microscopic level, requires less energy to climb the steep edge of the sprocket than it does on the flat edge. Therefore, movement is practically possible only in one direction.
A few years ago, a chemically driven nanomotor with 78 atoms had already been built , allowing a tiny computer to navigate a human body looking for tumors at their earliest stage, for example. Ben Feringa, from the University of Groningen, in the Netherlands, built another engine even smaller: 58 atoms , and also powered by solar energy.
These molecular motors also exist in nature, for example in the form of myosins : motor proteins that play an important role in living organisms in the contraction of muscles and the transport of other molecules between cells.