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[2012.09.12]驚奇的新發明---聲波懸浮器( acoustic levitator)


新聞翻譯概要:

美國 DOE Argonne National Laboratory 研發出利用聲波來懸浮 水滴,
並讓它於浮在中空下一段時間。其懸浮器是由兩個小型一上一下的揚聲器所組成,
並產生約22kHz頻率的聲波,當從上和下方揚聲器的聲波對齊後即可創造駐波。

因為波的節點沒有淨能量轉移,並由於較輕的物體上(如水滴)重力的影響會受到從聲波的壓力而抵銷掉,所以使得水滴懸浮起來。未來將發展應用於藥物
的無容處理(containerless processing)
  • Video :
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  • News Of New Scienist :  (英文新聞轉貼)

These drops of liquid really are floating in mid-air. It's not a trick photo and they're not in the microgravity of space. But NASA does have something to do with this wizardry: an acoustic levitator that the agency originally developed is holding the droplets in place.

The levitator consists of two small speakers, one above the other, which generate sound waves at frequencies of about 22 kilohertz - slightly higher than humans can hear. When the sound waves from the top and bottom speakers are aligned they create a standing wave. At the nodes of this wave there is no net transfer of energy and pressure from the sound waves cancels the effect of gravity on light objects like these drops.

This technique has been developed at Argonne National Laboratory in Illinois as part of a search for methods of "containerless processing" for drug development. When extracting pharmaceuticals from solution in a container, the chemicals often take their crystalline form. Take away the container, though, and many drugs retain an amorphous structure, which allows the body to absorb them more efficiently. This in turn means they require smaller doses to be effective.

"One of the biggest challenges when it comes to drug development is in reducing the amount of the drug needed to attain the therapeutic benefit, whatever it is," said Chris Benmore, who led the study. The levitating liquids can also be probed in situ with high-energy X-rays so the team can watch chemical processes in the levitating liquids.

news :
http://www.newscientist.com/blogs/shortsharpscience/2012/09/floating-drugs.html
http://www.anl.gov/articles/no-magic-show-real-world-levitation-inspire-better-pharmaceuticals

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