Streams of sound are now all you need to make objects dance in the air and combine. A levitation device is the first to use high-frequency sound waves to bring together floating particles and liquid droplets. In principle, the technique could even levitate a person or animal – although it’s not strong enough yet.
For now, such hands-free control could be used to study chemical reactions in extreme environments, to move hazardous materials and to simulate the low-gravity environment of space. At 24 kilohertz, the waves are too high-pitched to be audible to humans – but can be heard by some animals, including cats, bats and mice.
Other levitation methods use magnets or electrical fields, making mag-lev trains – and even levitating frogs – possible. But in these cases, the levitated objects must have particular magnetic or electrical properties.
Acoustic levitation imposes no such constraints. It can, in principle, float anything, says Dimos Poulikakos of the Swiss Federal Institute of Technology (ETH) in Zurich, Switzerland.
A sound wave is a pressure wave that produces a force and so has the potential to counteract gravity. To float things using sound, you need to ensure the force remains constant in a particular point in space.
This has been done previously, by using speakers or other resonators to fire pressure waves upwards and bounce them off a reflector. The original waves and their reflections then combine to create a standing wave, with a series of stationary "nodes" that stay put even as the wave oscillates.
If the standing wave has the right frequency, the force at these nodes exactly cancels gravity – and anything trapped there hovers in place.
"Scientists at Argonne National Laboratory have discovered a way to use sound waves to levitate individual droplets of solutions containing different pharmaceuticals. While the connection between levitation and drug development may not be immediately apparent, a special relationship emerges at the molecular level."
60 Years of Research Links Gluten Grains to Schizophrenia 2015-03-31 1:05
Does the consumption of gluten-containing grains contribute to psychiatric disorders such as schizophrenia?
Believe it or not, this question has been asked for well over 60 years by researchers who stumbled upon evidence that the removal of gluten from the diet results in improved symptoms, or conversely, that gluten grain consumption leads to higher prevalence of both neurological and psychiatric problems.
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Just what is your food made of, anyway? Try industrial synthesis, genetically modified mold secretions, hydrochloric acid, mercury-contaminated caustic soda, ferrocyanideâ€¦ and, of course, lots of GMO corn.
If common ingredients like â€ścitric acidâ€ť and â€śascorbic acid (Vitamin C)â€ť sound normal and familiar enough that you practically conjure up an image of the flourishing orchard they were grown in â€“ then ...
Thousands of migrants dumped on Britain as French wriggle out of border promise 2015-03-30 19:56
Thousands of migrants could be dumped on Britainâ€™s doorstep if France tears up a historic border agreement, it was claimed last night.
Officials have vowed to do â€śeverything in their powerâ€ť to wriggle out of a treaty moving the UK border to Calais.
The besieged townâ€™s mayor Natacha Bouchart is prepared to spark a major diplomatic row by opening the frontier ...
Richard III laid to rest at Leicester Cathedral 2015-03-30 18:36
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The monarch, who reigned from 1483 to 1485, was the last of the Plantagenet dynasty.
Actor Benedict Cumberbatch read a poem by Carol Ann Duffy during the service. Also in attendance was Robert Lindsay, who played Richard III in a version ...
Sweden - A new paradise for Romani beggars 2015-03-30 17:33
Thanks to the European Union and freedom of movement that follows with membership Sweden has been flooded with gypsies from Eastern Europe.
Most member states have cracked down hard on the phenomenon of organized begging with legislation and forceful evictions so the Romani (colloquially known as Gypsies) who are engaged in this venture have moved their business to the country where ...