Related ASU Web Sites
The Harrington Department of Bioengineering
Publication Date: Fall 2004
A beam of light comes in handy when looking for lost keys in a dark room. But it also can be a powerful tool for moving molecules of water. ASU scientists recently discovered that ordinary beams of light can be used to move tiny water droplets. Tony Garcia says the finding could have an important effect on the fledgling field of microfluidics.
Garcia is an ASU associate professor in the Harrington Department of Bioengineering. He and his colleagues are the first to demonstrate that a beam of light can be used to move microdroplets of water around on surfaces. They also used light to move droplets in extremely small channels, and to place them in predetermined positions for analysis.
The ASU researchers used nanotechnology techniques to make their discovery. In nanotechnology, scientists design and build devices one molecule at a time. As the overall size of these devices shrink, the nature of the surface plays an increasingly important role. Why? Because a greater percentage of the molecules in a nanotech device reside on the surface. Garcia says that the ability to manipulate surface molecules using everyday means, such as shining a light or connecting to a battery, is very important. Ordinary tools like pumps and valves are difficult to make on a nano scale.
“This discovery can speed the development of microfluidic devices,” he says. Scientists can use these tiny, sophisticated devices to analyze samples faster and more efficiently.
For example, using a microfluidic device, a laboratory technician might need only a single drop of blood to run a battery of 20 to 30 different tests. The patient would get results in the time spent waiting to consult with the physician.
“These devices also could help pharmaceutical companies screen for a new drug by allowing for tests to be run on an extremely small scale and in simultaneous fashion,” Garcia adds.
The ASU scientists are now working to design a device that can move drugs dissolved in water, or droplets of water and samples that need to be tested for environmental or biochemical analyses.—Skip DerraEngineering and Technology: Bioengineering