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September 12, 2012
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Joanne Manaster is a university level cell and molecular biology lecturer with an insatiable passion for science outreach to all ages. Enjoy her quirky videos at www.joannelovesscience.com, on twitter @sciencegoddess and on her Facebook page at JoanneLovesScience Follow on Twitter @sciencegoddess.
From Argonne Labs comes this intriguing video demonstrating the acoustic levitation of liquids on a piece of equipment developed for NASA to simulate microgravity conditions.
“The acoustic levitator uses two small speakers to generate sound waves at frequencies slightly above the audible range – roughly 22 kilohertz. When the top and bottom speakers are precisely aligned, they create two sets of sound waves that perfectly interfere with each other, setting up a phenomenon known as a standing wave.
At certain points along a standing wave, known as nodes, there is no net transfer of energy at all. Because the acoustic pressure from the sound waves is sufficient to cancel the effect of gravity, light objects are able to levitate when placed at the nodes.”
These drops of solution remain suspended for a long period of time, thanks to the vibrational force of sound waves that keep them stationary in an air column. (Photo by Dan Harris)
To learn more how it might be used to develop pharmaceuticals, read more at Argonne’s website.
About the Author: Joanne Manaster is a university level cell and molecular biology lecturer with an insatiable passion for science outreach to all ages. Enjoy her quirky videos at www.joannelovesscience.com, on twitter @sciencegoddess and on her Facebook page at JoanneLovesScience Follow on Twitter @sciencegoddess.
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Levitation is due to non-linear effects that occur as intense sound waves hit an object. One interesting use could be to separate gases, possibly. For example, a gas molecule with a larger mass can be concentrated at nodes in an intense standing wave. At what pressure and frequency would such a separation occur?
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