Microscopic drops of fluid form basis of new technology

SANTA ANA, Calif. — University of California, Irvine is studying how fluids work on a microscopic level — the way that tiny droplets can flow through hair-thin channels to analyze information or cool an electronic component.

The research could lead to everything from faster computers to tests that give rapid detection of tuberculosis to sensation in the fingertips of artificial hands.

Through a $7.2 million grant from federal and industry sources, UCI is nurturing this technology, called microfluidics, so that it can be translated into consumer products.

"This grant is long overdue," said Abraham Lee, a co-founder of UCI's new Micro/Nano Fluidics Fundamentals Focus Center. "Some of the technology is ready to go. The infrastructure will go a long way in terms of developing products to make this a reality."

Home diagnostic tool

One of Lee's graduate students, Armando Tovar, is working on a home diagnostic device, about the size of the face of a watch, for tuberculosis, malaria and smallpox.

"You just prick someone's finger and float the drop of blood through the device," Tovar said. The blood runs through several channels, separating into components and binding with protein markers of the diseases. It works "kind of like a pregnancy test" and shows "little black spots lighting up."

Tovar said it takes from 30 minutes to two hours to get a tuberculosis diagnosis on the chip, versus 12 to 48 hours to do something similar in a lab.

"Lab on a CD"

Marc Madou, a mechanical engineer at UCI, is working on a plastic device that he describes as "a lab on a CD."

His round, palm-sized creation is etched with microchannels that — when spun many thousands of times per minute — separate the components of blood samples to analyze for bacteria or viruses. The process takes less than an hour on Madou's device but generally would require more than two days in a lab.

Lee said a primary goal of this multischool and industry collaboration is to develop product standards.

"Everyone has their own chips and different pumps and valves. It's kind of like how before USB ports, everyone had a different way to collect data," Lee said. "This center will allow us to have a critical mass to work with companies to develop more standards."

The microfluidics center is also developing more finely tuned sensors. Jeff Fisher, a UCI graduate student, is developing pressure sensors for fingertips of prosthetic hands. The sensors are on a grid that's "no bigger than a postage stamp" with a reservoir of water and zigzagging microchannels. The fluid moves in and out of channels in response to pressure, and Fisher is collaborating with other researchers to allow these sensors to send signals up the arm to nerves.

"You can integrate the channels into softer plastic and it's more like real human skin," Fisher said. The microfluidics sensors, he adds, create a feeling that comes close to what people are born with. "There are naturally different layers with fluids moving around in the fingertips."

Cooling device

In computers, heat can be the enemy of function. And global defense contractor Northrop Grumman and Irvine Sensors in Costa Mesa, Calif., are two companies interested in using microfluidics technology to cool down computer chips. Cooler systems, they believe, could increase computing speed and allow for computations that aren't now possible.

Lee said the center may start research on water monitoring by creating chips that can be dropped in rivers or dams to check levels of toxins. Fisher envisions that one day there may be a chip in a fridge that can spit out instant calorie calculations or test whether an item is spoiled.

"The applications are endless," Tovar said. "It's about how much imagination do you have to go about it."