- An extremely tiny motor has just 16 atoms and shows groundbreaking "directional" motion.
- This tiny motor absolutely blows away previous tiny motors that were a comparatively gigantic 40 nanometers.
- The motor moves from thermal or electrical energy and is often predictably unidirectional.
Scientists have unveiled a functional motor made with just 16 atoms. The researchers, from the Swiss Federal Laboratories for Materials Science and Technology (Empa), made the tiny motor, which is less than 1 nanometer in diameter. Let’s take a very, very close-up look.
In the video, you can see an inset of real imaging of the nanomotor along with a more legible illustration of it with colors and clearer shapes. “We have realized and investigated an artificial molecular motor applying scanning tunneling microscopy, which consists of a single rotor anchored to a surface that acts as a stator,” the team writes. (The stator is just the base that the rotor attaches to in order to spin—stator like static or stationary.)
The tiny motor, its creators say, represents a shift from classical motion into quantum motion for a nanomotor of this size. It often operates in a ratchet motion, meaning that, like a socket wrench or fixed-gear bicycle pedal, it doesn’t spin “backwards” and lose energy or progress.
Even when the rotor is using quantum tunneling in order to move, that phenomenon is expected to be random in direction, not predictable, let alone predictably unidirectional.
Motor motion is provoked by thermal energy or electrical energy, with different results. Electrical energy induces consistent unidirectional rotation. Thermal energy makes the rotor move randomly, but too much electrical energy causes this more chaotic movement, too. It seems the tiny motor can be controlled by applying a steady flow of just one electron at a time. But the fact that there are differences between the two energy sources, and that the rotor is ever consistent and unidirectional, is important.
The researchers say this combination of quantum action and classical laws can tell us something about the way quantum tunneling systems work. Typically, tunneling particles don’t lose any energy, but the spinning motion here indicates the spinning rotor particles are losing energy that helps to keep propelling them “forward” in the same direction as a consequence of the Heisenberg uncertainty principle.
That’s a rich vein for future research in itself, but the cool thing about a motor this tiny that ever acts in a predictable way is it can potentially be used as a “real” motor. The team says this “degree of directionality” represents the “extreme limits” of molecular machines.
“This ultrasmall motor thus opens the possibility to investigate in operando effects and origins of energy dissipation during tunneling events, and, ultimately, energy harvesting at the atomic scales,” the scientists explain in the paper.
That means if the loss of energy within this tiny motor can be well understood and consistently recreated, the tiny motor itself could be used to generate steady energy for other tiny systems. It’s one nano-scale step for motors, but one giant leap for quantum-kind.
Caroline Delbert is a writer, avid reader, and contributing editor at Pop Mech. She's also an enthusiast of just about everything. Her favorite topics include nuclear energy, cosmology, math of everyday things, and the philosophy of it all.
