Scientists levitate water, but unlike Harry Potter no wands are
needed. Instead, scientists used sound waves to levitate droplets
of water.
How does it work?
Scientists used an acoustic levitator. The levitator is made of
two small speakers which create two sets of sound waves at 22
kilohertz, which humans can't hear.
The two sets of sound waves that interfere with each other. The
pressure generated by these two sound waves is high enough to
counteract the effects of gravity. This allows light droplets of
liquid to levitate, if scientists put them in the right place
amongst the sound waves.
What's the point of levitating water?
Liquid levitation can help scientists to make medicines with
fewer side effects. Medicines come in two categories - amorphous
and crystalline.
Amorphous medicines are absorbed by the body quicker, so you can
take a lower dose. But, amorphous medicines are difficult to
make.
When scientists make medicines, they first make a liquid
solution of the medicine. The water needs to evaporate off from the
liquid, to produce a solid medicine. If the liquid touches the
sides of a container, it can crystallise. Crystalline medicines are
harder for the body to absorb, so a bigger dose is needed. A bigger
dose of medicine can cause more side effects.
If scientists can levitate their liquid medicine solution, the
medicines won't crystallise. Instead, the water will evaporate,
leaving an amorphous medicine behind.