Ann Conkle
May 11, 2012

Portable diagnostics shaken, not stirred

As researchers aim to shrink diagnostic tools, one question is how to easily move and mix small samples of liquid. But, University of Washington researchers have now built and patented a surface that moves drops along certain paths to conduct medical or environmental tests. The team used nanotechnology manufacturing techniques to build a surface with tiny posts of varying height and spacing. When a drop sits on it, it makes so little contact with the surface that it's almost perfectly round and even a small jiggle can move it. Researchers used an audio speaker or machine to vibrate the platform, moving individual drops along predetermined paths to mix, modify or measure their contents. "All you need is a vibration, and making these surfaces is very easy. You can make it out of a piece of plastic," Böhringer said. "I could imagine this as a device that costs less than a dollar -- maybe much less than that -- and is used with saliva or blood or water samples."