Smallest heat engine yet
THE journal Science reports German scientists have built the world’s smallest heat engine, using only one atom.
Much bigger heat engines have helped shape modern society by transforming thermal energy into mechanical force.
The researchers, led by Professor Kilian Singer, now professor at the University of Kassel, used a Paul trap to capture a single electrically charged calcium atom. This atom can be heated with the help of electrically- generated noise and cooled by using a laser beam.
As a result, the atom is subjected to a thermodynamic cycle. This means that the particle moves back and forth within the trap, thus replicating the stroke of a typical engine. The atom not only acts in the same way as an engine but also stores the energy.
The researchers say their single particle engine can generate power of 10- 22 Watts and operates at 0,3% efficiency. If scaled up, its output would be equivalent to that of a car engine. The cycle can also be reversed to cool nano systems.
The aim of nano- engine research is, however, to provide insight into thermodynamics at the single- particle level, which is currently a very hot topic in research. The VW Foundation funds the project. — WR.