In the new system, known as a three-dimensional AC electro-osmotic pump, tiny electrodes with raised steps generate opposing slip velocities at different heights, which combine to push the fluid in one direction, like a conveyor belt. Simulations predict a dramatic improvement in flow rate, by almost a factor of twenty, so that fast (mm/sec) flows, comparable to pressure-driven systems, can be attained with battery voltages. Experiments in the lab of Todd Thorsen, assistant professor of mechanical engineering, have recently demonstrated the effectiveness of the design.
"It's just a huge improvement with a very simple idea," said Bazant.
Thorsen's group is working toward integrating the pumps into a portable blood analysis device, which soldiers could carry onto the battlefield. If exposure to chemical or biological weapons were suspected, the device could automatically and rapidly test a miniscule blood sample, rather than sending a large sample to a lab and waiting for the results. The chips are so small and cheap to make that they could be designed to be disposable, Bazant said, or they could be made implantable.
Potential applications are not limited to military use - imagine going to a doctor's office and getting test results immediately. The technology could also be useful for first responders. If emergency personnel knew immediately whether a person had suffered a heart attack or a stroke, they could start the appropriate treatment right away.
Labs on a chip can also be used in traditional chemistry or biology labs to speed up processes such as DNA testing or screening for the p
Source:Massachusetts Institute of Technology