Researchers create working single-atom engine in world first

15 Apr 2016

View of the vacuum chamber containing the atom trap. Image via JGU/Ag Quantum

It seems engineering things the size of atoms is all the rage these days, as a team of Swiss researchers announces it has found a way of creating a functioning engine using a single calcium atom.

The single-atom engine described by the researchers works in an almost identical way to the internal combustion engine found in cars. When the engine is running, the air within the chambers expands then cools before it then contracts and heats.

Detailing the team’s findings in a paper, the researchers from Johannes Gutenberg University Mainz (JGU) said that they had used something known as a Paul trap to capture a single electrically charged calcium atom.

To put this into perspective when comparing to previous particle-sized engine attempts, the record until now saw engines the size of 10,000 particles.

Once the team had successfully ‘caught’ an atom, electrical noise surrounding the atom would be generated, creating heat that could then be cooled using a precise laser beam.

This subjects it to the same thermodynamic cycle experienced within a typical engine, causing the single particle to move back and forth within the trap, thereby becoming its very own engine on a seemingly-unfathomable scale.

Equal in efficiency to car engine

Based on the team’s calculations, the single-atom engine generates power of 10-22 watts with an operational efficiency of 0.3pc.

If this model was increased to the size of a typical car engine, the two engines would have very similar power outputs.

Laser system

Part of the laser system used to alternately heat and cool the atom. Image via JGU/ AG Quantum

The theory behind the single-atom engine was first proposed by the current study’s first author, Johannes Roßnagel, back in 2014 as a means to investigate thermodynamic quantum effects, but Roßnagel now says this breakthrough could have other properties, too.

“By reversing the cycle, we could even use the device as a single atom refrigerator and employ it to cool nano systems coupled to it,” he said.

Sadly, no nanobots engine

And yet, speaking to Popular Mechanics, Roßnagel has thrown a dampener on anyone hoping that this technology could one day power a fleet of nanobots in the human body, as recently discussed during’s feature on a micropowered future.

Adding some possible hope, however, he added that “this improved understanding can (and will, I’m convinced) lead to a next generation of experiments and to future devices which will be interesting for various applications”.

This announcement has coincidentally coincided with the revelation that a team from Switzerland has been able to create a functioning magnet the size of an atom.

A magnet at this scale, the team believes, could lead to the creation of much smaller hard drives than current standards, but much more research has to be undertaken before that is a reality.

Colm Gorey was a senior journalist with Silicon Republic