A tiny pump promises big time performance

BU invention could ’sweeten’ diabetes therapy within five years

C.J. Zhong hopes that within the next three to five years diabetics the world could see their quality of life enhanced by his tiny invention-a chip-sized pump with no moving parts. The device is also expected to find its way into myriad industrial and environmental applications, where it could mean huge savings in manufacturing and monitoring processes.

Zhong’s patent on the low-power, electrically driven pumping device is one of the reasons the State University of New York has broken into the U.S. Patent and Trademark Office’s list of the top 10 patent-producing U.S. universities, jumping to 8th in 2002 from 17th in 2001.

Zhong was among four Binghamton researchers honored last week by State University of New York Chancellor Robert L. King for their contribution to the advancement of humanity through groundbreaking research. Zhong was recognized with a First Patent Award for his device. (See related story.)

An assistant professor of chemistry at Binghamton since 1998, Zhong refers to the invention as a “pumpless pump” because it lacks mechanical parts. The pumping device is the size of a computer chip and could be fabricated at a scale comparable to an adult’s fingernail. The device comprises a detector, a column filled with moving liquid, and an injector. The pumping action is achieved when a wire sends an electrical voltage to two immiscible fluids in a tiny column, perhaps as small as the diameter of a hair. Applying opposite charges to each side of the column causes the fluids to oscillate, thereby simulating the action of a pump. In some ways, the tiny system works like a thermostat: it takes a small sample, analyzes it, and tells other components how to act in response.

Zhong’s device has significant potential in the treatment of diabetes because it is small enough to be inserted into and remain in the body where it would conduct microfluidic analysis, constantly measuring the need for insulin and, then, delivering precise amounts of insulin at the appropriate times. Because the detector would remain constantly at work, the device could eliminate the need for regular blood tests. Moreover, because less time would have passed between infusions of insulin, it is likely that insulin levels could be better maintained, without soaring and surging as dramatically as they sometimes do with present day treatment strategies. While his device is not an “artificial pancreas,” Zhong says that it could well prove to be an integral part of a system that could someday become just that.

Diabetics are not the only ones who will benefit from the tiny pumping device, developed by Zhong and his research team of undergraduate and graduate students and a post-doctoral researcher. Any small, closed environment could benefit from tiny equipment that requires little fuel and produces no waste, he said.

“For example, there’s the space shuttle,” Zhong said, “If you want to analyze the water quality, this would allow you to take as small a sample as possible.” That would make it possible for astronauts on an especially long mission to ensure the potability of their water supply without significantly depleting their supply by repeated testing, he added.

Zhong’s pumping device can also be operated by remote control, working where human hands cannot — or should not reach. “One of the labs we’re working with on this project is interested in dealing with metal contaminants from nuclear waste,” said Zhong. “Their current technology is to go in the field, take samples of contaminated soil, and analyze them back in the lab. What we want to do is make remote controllable portable chip devices that sit in the field.”

Making lab equipment smaller and more efficient is one of Zhong’s chief research goals. It’s a goal he sees as highly achievable.

“Look at the computer,” he said. “Twenty years ago, it was huge. Now it’s tiny.” He eventually hopes to create what he calls a “lab on a chip,” by shrinking down all of the equipment in a chemistry lab to the size of computer chips. Smaller equipment not only uses fewer resources, he said, but creates less waste.

“Large equipment typically generates significant waste,” he said, “But if you use a miniature instrument, there’s almost no waste.” For example, because his new pump is so small, it runs on an electrical current supplied by a tiny battery. A conventional pump requires the power of a generator, which needs gasoline and emits toxic fumes as a byproduct.

Regardless of the size at which it is produced, the design of Zhong’s device has any number of advantages over current technologies. “Mechanical parts need maintenance and repair,” he said. “This is basically a fluid pumping mechanism,” with no need for lubrication, repairs, or spare parts. Produced at the scale of a chip, it is also practically weightless, especially compared to a conventional pump.

Right now, Zhong’s invention is still in the prototype stage, but the weightless, maintenance-free and implantable “pumpless pump” probably is not too far off, he speculated. “We are not there yet, but this is going to take off very fast,” he said. “Perhaps three to four years.”

That might not seem soon enough for diabetics who would gladly trade lancets and blood test strips for a tiny internal sensor attached to an insulin pump. But Zhong’s miniature invention nevertheless seems likely to soon be making life much sweeter for many in the health care, manufacturing and environmental arenas.