INSIDE BINGHAMTON UNIVERSITY
Miniature pump has big potential
By : Ingrid Husisian
A low-power electrically driven pumping device, developed by a chemistry professor and his team of undergraduates, graduate students and a post-doctoral researcher, could significantly enhance the quality of life for diabetics around the world.
C. J. Zhong, assistant professor of chemistry, is leading the effort on a low-power, electrically driven pumping device that will be able to perform microfluidic analysis and potentially remain in the body, constantly measuring it for insulin and delivering precise amounts.
Zhong has dubbed it a “pumpless pump,” because it lacks mechanical parts. A wire sends an electrical voltage to two immiscible fluids in a tiny column, which could be 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.
The pumping device will be the size of a computer chip, perhaps as small as an adult’s fingernail, said Zhong. It is made of a detector, a column filled with moving liquid and an injector.
The detector, a tiny electrical wire, measures the body’s insulin level and responds by electrically charging the fluid in the column to make it move. The motion in the column triggers the injector to supply the body with more insulin from an external source. The detector works constantly, eliminating a diabetic’s need for regular blood tests. Because less time has passed between injections, insulin levels do not soar and surge as dramatically as when the diabetic person must constantly monitor blood glucose level and respond to a need for more insulin with injections. This tiny system works like a thermostat: it takes a small sample, analyzes it and tells other components how to act in response.
Zhong’s pumping device will be so small that doctors can insert it into the body, eliminating the need for round-the-clock blood tests and injections. It will be wireless, so the diabetic patient can wear a small battery pack to power it. He stresses that the pump is not an “artificial pancreas,” but is merely one part of a system that could someday be just that.
Diabetics are not the only ones who will benefit from this tiny pumping device. Every small, closed environment, said Zhong, can benefit from miniature equipment that requires little fuel and produces no waste.
“For example, there’s the space shuttle,” he said. “If you want to analyze the water quality, you can take as little a sample as possible. If it’s a long duration, the supply is going to run out, and the astronauts have to make sure the water is drinkable.”
He said the pumping device can also operate via remote control, 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-controlled portable chip devices that sit in the field.”
Making lab machinery smaller and more efficient is one of Zhong’s chief goals. He cites computers as examples of things that have evolved from being large and slow to small and fast. He hopes to create what he calls a “lab on a chip” by shrinking the machinery in a chemistry laboratory to the size of computer chips.
Smaller equipment uses fewer resources and creates less waste because less fuel is necessary to run it. Consider the difference between a Mack truck and a Volkswagen. Because Zhong’s new pump is so small, it runs only on an electrical current supplied by a tiny battery. A conventional pump could require the power of a generator, which needs gasoline and emits toxic fumes as a by-product.
The big advantage to Zhong’s device is its design. While mechanical parts need maintenance and repair, in the “pumpless pump,” an electrical current creates the motion by moving fluid through a channel — no need for lubrication, repairs or spare parts. The system is also practically weightless, especially compared to conventional pumps.
The invention is still in the prototype state, but mass production, said Zhong, is not far off. “This is going to take off very fast,” he said — perhaps within three to four years. Even so, it’s probably not fast enough for diabetics who would gladly trade lancets and blood-test strips for a tiny internal sensor attached to an insulin pump. For something so small, it could be a huge lifesaver.