Paper strips serve as laboratory.

• Position: Microfluidics

A technique that uses inexpensive paper to make "microfluidic" devices for rapid medical diagnostics and chemical analysis has been invented by researchers at Purdue University, West Lafayette, Ind. The innovation represents a way to enhance commercially available diagnostic devices that use paper-strip assays like those that test for diabetes and pregnancy.

"With current systems that use paper test strips you can measure things like pH or blood sugar, but you can't perform more complex chemical assays," notes Babak Ziaie, professor of electrical and computer engineering and biomedical engineering. This new approach offers the potential to extend the inexpensive paper-based systems so that they are able to do more complicated multiple analyses on the same piece of paper. It's a generic platform that can be used for a variety of applications."

Current lab-on-a-chip technology is relatively expensive because chips must be designed specifically to perform certain types of chemical analyses, with channels created in glass or plastic and tiny pumps and valves directing the flow of fluids for testing. The chips are being used for various applications in medicine and research, measuring specific types of cells and molecules in a patient's blood, and monitoring microorganisms in the environment and in foods, and separating biological molecules for laboratory analyses--but the chips, which roughly are palm-size or smaller, are difficult to design and manufacture.

The new technique is simpler because the testing platform will be on a disposable paper strip containing patterns created by a...