MaxPlanckInstituteForIntelligentSystems
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Researchers build world's smallest steam engine that could
Wanna create your very own microscopic steam engine? Just take a colloid particle, put it in water, and add a laser. That's a CliffsNotes version of what a group of German researchers recently did to create the world's smallest steam engine. To pull it off, engineers from the University of Stuttgart and Max Planck Institute for Intelligent Systems tweaked the traditional approach introduced by Robert Stirling nearly 200 years ago. In Stirling's model, gas within a cylindrical tube is alternately heated and cooled, allowing it to expand and push an attached piston. Professor Clemens Bechinger and his team, however, decided to downsize this system by replacing the piston with a laser beam, and the cylinder's working gas with a single colloid bead that floats in water and measures just three thousandths of a millimeter in size. The laser's optical field limits the bead's range of motion, which can be easily observed with a microscope, since the plastic particle is about 10,000 times larger than an atom. Because the beam varies in intensity, it effectively acts upon the particle in the same way that heat compresses and expands gas molecules in Stirling's model. The bead, in turn, does work on the optical field, with its effects balanced by an outside heat source. The system's architects admit that their engine tends to "sputter" at times, but insist that its mere development shows that "there are no thermodynamic obstacles" to production. Read more about the invention and its potential implications in the full press release, after the break.
Researchers produce cheaper, 'cooler' semiconductor nanowires
Advances in nanowires may occur on a pretty regular basis these days, but this new development out of Germany's Max Planck Institute for Intelligent Systems could have a particularly big impact on one all-important area: cost. As PhysOrg reports, manufacturing semiconducter nanowires at an industrial scale is currently very expensive because they need to be produced at extremely high temperatures (600 to 900 degrees Celsius), and the process used to manufacture them generally uses pure gold as a catalyst, which obviously adds to the cost. This new process, however, can use inexpensive materials like aluminum as a catalyst, and it can produce crystalline semiconductor nanowires at temperatures of just 150 degrees Celsius. Of course, that's all still only being done in the lab at the moment, and there's no indication as to when it might actually be more widely used.
