With a little luck, you can jumping drops can be observed. For example, outside on the window sill when the rain starts. A drop of water approaches the surface and something jumps out in fact, again in the height, like a rubber ball. High-speed cameras show much better than the human eye can see what is going on. After the landing of the drop runs wide, runs quickly and jumps to the top.
This spring the end of drop but also can be made to rotate. And does it really quickly. A rotation speed of up to 7300 Revolutions per Minute have reached their droplets, reports Chinese scientists to Huizeng Li in the journal “Nature Communications”. “We have shown for the first time that a rectilinear motion may be converted to a push on a wettable surface in a rotary motion,” says the research head of Yanlin Song, Chinese Academy of Sciences. The phenomenon could be used for energy production.
Tiny spirals put the drops in rotation
the drop to Rotate, have changed, the researchers surfaces in a targeted manner. It is, in a sense, tiny, spiral-shaped “dikes”, which were capable of and “sticky”, while the environment was less friendly and water-repellent. In principle, different materials can be used to locally specific properties, explained Yanlin Song. His Team used anodized aluminum oxide, but also silicon and polymers.
In the video, the researchers show, what is the effect of the Spiral-levees and the Interaction of different surface properties: liquid drops fall down, spread on the surface evenly in all directions, like a pancake. In the following, however, is the return of the parts of the liquid at different speeds and on curved paths in the form of drops, wherein the spiral brings an additional Rotation. As a result of the new drops jumps to the top, and at the same time turning rapidly around its own axis.
The rotational energy, one could use
What is a nice Trick, and could in the future be used for energy. During the impact the linear kinetic energy of the drop will partially converted into rotational energy. And this could be transferred, at least in part, on the location, explained Yanlin Song. “This rotation of the pad we want to use to generate electricity.”
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not solved, it Is easier to collect rain drops in a pool and operate at the bottom of a conventional water turbine, as conventional water power plants do? “We use a new principle, the components are easier and cheaper to manufacture,” says Yanlin Song. “But what is even more important: After using the new method has already been gained energy from the drops, you can collect, you is still in a Reservoir and later through a Turbine to generate further electricity.” So at least the idea. To succeed, it is still more research work is needed.
