Wetenschapsforum

Heat engine may be world's smallest


Physicists in the Netherlands have built a heat engine that might be the tiniest ever created. Based on "piezoresistive" silicon, and smaller than a typical biological cell, the engine could find applications in watch mechanisms or as a mechanical sensor.


Engines come in a variety of sizes. The smallest include biological engines such as the flagella that bacteria use for locomotion, which are driven by chemical reactions, or manmade electrostatic engines, which drive ions with electric fields.


But heat engines, which usually rely on the expansion and contraction of liquids or gas, are trickier to downscale. As the devices get smaller, engineers find it harder to design structures that can handle the high pressures and fluid velocities required for a reasonable power output. The efficiency also tends to decrease, because it requires large temperature differences as given by the famous Carnot heat-engine equations. For these reasons, liquid- or gas-driven heat engines rarely get smaller than around 107 µm3.


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Lees verder: http://physicsworld.com/cws/article/news/44794


Bron: Physicsworld.com


Wetenschappelijk publicatie: Steeneken, P. G., K. Le Phan, et al. (2011). "Piezoresistive heat engine and refrigerator." Nat Phys advance online publication. DOI: 10.1038/nphys1871


Steenekens werkt bij NXP Eindhoven btw.