Sep. 14, 2012 at 12:36 PM ET
Scientists have figured out how to use sound waves to levitate droplets of liquid. While the phenomenon is gee-whiz cool in its own right, the technique could lead to the development of new drugs that the body efficiently absorbs.
The contraption consists of two small speakers that generate sound waves at frequencies slightly above the audible range, roughly 22 kilohertz. The speakers are aligned one above the other so that their sound waves interfere with each other and create what’s called a standing wave.
At points along the standing wave known as nodes, the acoustic pressure from the sound waves is sufficient to cancel out the effect of gravity, enabling light objects such as droplets of liquid to levitate when placed there, according to a press release from Argonne National Laboratory.
As seen in the video below, there are several nodes between the speakers, allowing Argonne researchers to levitate several droplets at once.
The phenomenon was originally pioneered at NASA to simulate microgravity conditions. Chris Benmore, an Argonne X-ray physicist, and colleagues turned to the technique to figure out how to get the chemical compounds of drugs into a state that is more readily absorbed by the body.
At the molecular level, the lab explained, pharmaceutical structures fall into two categories: amorphous or crystalline. Amorphous drugs are more highly soluble and have a higher bioavailability, meaning they can be given at lower doses to get the desired effect.
The problem is getting a pharmaceutical from a solution into an amorphous state is difficult. If a solution evaporates while it is in contact with a container, it is far more likely to solidify in its crystal form.
One way to “amorphize” the drug, the researchers reckoned, was to evaporate a solution without it touching anything. The acoustic levitator was the solution.
What’s more, the samples can be studied with the lab’s high-energy X-ray beam while it is being processed, allowing the researchers to understand the conditions that make for the best amorphous preparation.
The lab is currently pursuing a patent for their technique and partnering with academic researchers to determine which drugs their technique will impact most strongly.
— via Talking Points Memo