Richard Brown, professor and interim chair, Electrical Engineering and Computer Science, explained that a microsensor of this size and capability is possible because of MEMS (microelectromechanical systems) technology. Yet the single-chip sensor (right) that he developed doesn’t require the micromachining of silicon that much of MEMS does.

His work goes back to his PhD dissertation at the University of Utah. He developed an array of sensors with integrated electronics and the process to make them. His work continued when he arrived at the University of Michigan. It received attention, he said, but the sensors weren’t commercially viable due to short lifetimes, signal drift and manufacturing technology. He’s solved the problems, and the sensors are being sold commercially for the chemical analysis of water.

While they still “won’t live forever,” they’re inexpensive enough—well under $10 each to manufacture—to be disposable. Unlike macro sensors that cost in the $150 range, they don’t require any maintenance.

Applications abound, Brown said. They include bedside clinical diagnostics (monitoring blood sugar, electrolytes, blood gases), industrial applications (monitoring water hardness and pH to protect machinery), swimming pools and spas (monitoring chemical levels) and drinking water (monitoring for arsenic, mercury, lead and other contaminants). “In every case, sensors change the sensing activity from one that ought to have a chemist doing it—and that takes quite a bit of time and expense—to something that’s quick and simple, that anyone can do.”