November 4, 2005

Biomedical Engineer Shrinks Laboratory to a Chip

Dr. Glenn Walker shows a lab-on-a-chip device in his right hand. This device could eventually replace the 96-well tray (shown in his left hand), which is commonly used for laboratory testing. (Photo: Becky Kirkland)

Even in a world that seems obsessed with the miniaturization of everything from computers to cellphones, the idea of shrinking a laboratory to the size of a chip seems a little too much like science fiction. But in the Tiny Biotools Laboratory at North Carolina State University, Dr. Glenn Walker, assistant professor of biomedical engineering, is making it a reality. An expert in microfluidics, he has developed lab-on-a-chip (LOC) technology that will revolutionize laboratory testing.

In his office Walker opens a glass dish that sits on his desk; it is about the size of the palm of his hand. Inside is a small glass slide with an even smaller chip attached to it. Tiny hoses protrude from the top of the chip like thin spaghetti. Walker holds up a 96-well tray typically used in laboratories for running multiple tests. “This,” he says, gesturing to the chip, “replaces this,” gesturing to the tray. “We can run the same tests on this small chip. And we”ve found that when we use the microfluid technology, the results are more accurate,” he adds.

Walker”s recent work has focused on creating microfluidic versions of high throughput screening systems for toxicity assays, but the technology can be applied to many other laboratory tests, allowing researchers and technicians to conduct many times more tests and experiments simultaneously while reducing the volume of chemicals needed by 99 percent.

	The lab-on-a-chip device shown here allows researchers to conduct many times more tests and experiments simultaneously while reducing the volume of chemicals needed by 99 percent. (Photo courtesy Dr. Glenn Walker)

According to Walker, there are several advantages to LOC technology. Fluids at the microscale have unique properties that allow them to perform unique functions. For example, surface tension can be used to guide fluid flow. This phenomenon can be used to create “virtual walls,” as others in the field have demonstrated. Imagine a pipe with water in it, and then take away the walls of the pipe. The water will not spill out but will keep flowing like it is in the pipe—this is the power of microfluidics. And the behavior of the fluids is more predictable, making results from biological and chemical experiments accurate.

When testing a drug on cells in a traditional lab, scientists need enough medium and sample to fill several vials to run just a few tests. But using LOC technology, researchers can run multiple tests with just a fraction of the sample and medium. For example, one test of five concentrations of a chemical on cells would traditionally require tens of thousands of cells with a few milliliters of chemicals diluted by hand into different concentrations. The LOC technology will allow a researcher to run the test using a few hundred cells and a few microliters of chemicals. And the LOC can be designed to automatically make hundreds of different chemical concentrations. The reduced cost and greater accuracy make this technology the next revolution in drug testing and research.

The chip component of the LOC is made from micromolded polydimethylsiloxane (PDMS), which is bonded to a glass slide. The micromolding process can be adapted to a wide variety of plastics and is an attractive way for devices to be mass-produced.

“These devices will change the way that toxicity assays are performed,” says Walker. “It will make the process much less expensive, more efficient and more accurate.”

— weston —

Media contact:
Jennifer Weston, (919) 515-3848, weston@ncsu.edu

Technical contact:
Dr. Glenn Walker, (919) 513-4390, gmwalker@ncsu.edu

/ News Index / News Archives Index /