To be able to control and manipulate the nano-world as we control and manipulate objects that are our size is the goal of nanotechnology.  To scale down the machinery that we use everyday.  Image being able to harness the power of an engine that was made of only one atom.  

That is precisely what German researchers did when they constructed a single-atom hear engine, the smallest heat engine ever built.  (See the video below on how heat engine work.)  They were able to measure its energy output at 3.4x 10-22 watts.  By mass, making it as efficient as a car engine.  They published their findings results in the journal Science.

Heat engines took hold during the Industrial Revolution because of their ability to convert thermal energy into mechanical energy.  Recently there has been a push to construct smaller and smaller thermal machines.

The designed the single-atom engine to act like a normal-sized engine.  By using a trapped calcium ion that could only move along one axis, they were able to generate motion by creating temperature differences.  The resulting motion was an action that is similar to a piston in an engine.

This single-atom engine was measured to have an efficiency of just 0.28%.  Well behind the efficiency of a car engine which are about 25-30% efficient.  While this might seem incredibly low, it actually falls inline with the theoretical expectations.

Although a daily use of this technology is not likely, it does open some doors in applied and theoretical physics.  The single-atom engine could potentially power other nanotechnologies possibly single-atom refrigerators.  

“A whole lab of lasers, electronics, and vacuum chambers is needed to run this single atom engine,” noted Dr. Roßnagel. “However, we do fundamental research and try to get a better understanding of the thermodynamics of single particles.

“This improved understanding can (and will, I’m convinced) lead to a next generation of experiments and future devices which have interesting applications.”