You know how Stirling engines work, don’t you? If you don’t you can make an idea by imagining a cylinder with a fixed quantity of gas inside that expands when hot and compresses as it loses heat, creating movement and perhaps moving a piston (just like in the picture).
That’s a 200-year-old idea, but now two German researchers replicated this principle at the micro-scale.
Clemens Bechinger and Valentin Blickle from the University of Stuttgart came across the idea of replacing the cylinder with a laser containing a 3-micrometers wide piece of melamine. The entire experiment happens in water.
A second laser heats the “cylinder” and makes the melamine particle to break free, just like compressed gas. Then, the researchers modify the first laser and let the particle do the movement and spend the energy received from the second laser.
Although it might seem useless, this modern-day micro-Stirling engine could one day power devices as small and could be powered by minute sources of heat.