Microminiature steam engine successfully made in Germany

German engineers have successfully made a microminiature steam engine with its width at only a few thousandth of a millimetre wide, local media reported on Tuesday. \"The machine is so small that its motion is hindered by microscopic processes which are of no consequence in the macroworld,\" said the researchers at the University of Stuttgart and the Max Planck Institute for Intelligent Systems. \"This experiments give an insight into the energy balance of a heat engine operating in microscopic dimensions,\" the research staff said, adding that there are no thermodynamic obstacles to prohibit this in small dimensions. The whole technical process differs from that of a steam engine on the macro level, as a plastic bead able to float its water and then a focused laser beam has to be used in the bead to control its motion. Technicians used another laser to heat the water, in a simulation of the coal fire of a typical steam engine. The bead is roughly 10,000 times larger than an atom and can only be observed with microscopes. Technicians used the lasers to turn on and off quickly enough to get the bead to expand and contract just as functioning as a piston.