Acoustic Levitation: Sound Waves Make Drug Droplets Float In Mid Air

I never heard of the phrase ‘acoustic levitation’ before today, but it simply refers to the use of sound waves to levitate things. In this particular case, scientists at Argonne National Laboratory have figured out a way to levitate drops of solutions which all contain pharmaceutical drugs. This is a fascinating breakthrough – not because watching levitated drops of pharmaceuticals looks like a magic show (although it is definitely real), but because this will allow for further enhancement of drug research and development.

The relationship between acoustic levitation and drug development is not immediately obvious, but it exists. I’m going to oversimplify the explanation for the sake of this article, but you can always click over here on the Argonne National Laboratory for all the geeky details.

According to physicist Chris Benmore who leads this research, “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.” Because of how they are developed, most drugs are crystalline, which means they aren’t fully absorbed into the body. This means we are taking a higher dose than necessary just so a percentage of that will be absorbed into our bodies.

In order to fix that, drugs need to be in an amorphous state, not a crystalline state. This would have to happen while the drug is in a liquid form, and it would have to happen without it touching anything. Those two things together made it seem impossible since a liquid is always touching something. However, that is where acoustic levitation comes in. Levitation is referred to in this community as “containerless processing.” Acoustic levitation will greatly assist in the further development of better, more effective pharmaceuticals that can be administered in smaller doses.

In order for this acoustic levitation to work, the speakers are turned on at 22 kilohertz. At that point, each drop of the drug solution is carefully placed for amorphous preparation. It can then evaporate without touching anything. Right now this is a tedious process since only a few drops can be worked with at one time, but it’s definitely a step in the right direction. All this science aside, I’d love to play around with drops of water and try to make them levitate like this!