New 'self-calibrating MEMS' bringing accuracy to nanotech

Researchers have demonstrated tiny machines that could make possible super-accurate sensors and motors, with far-reaching applications from computer storage to altimeters, detecting petroleum deposits to measuring DNA-binding forces.

The machines are called self-calibratable micro-electromechanical systems, or MEMS. Although MEMS are in commercial use, the new device is the first of its kind capable of self-calibration, a step critical for applications requiring high performance and accuracy, said Jason Vaughn Clark, an assistant professor of electrical and computer engineering and mechanical engineering at Purdue University.

"Self-calibration is needed because each MEMS device is slightly different due to variations that occur in manufacturing," he said. "Small variations in microstructure geometry, stiffness, and mass can significantly affect performance. Because of this variability, no two MEMS behave identically. Since conventional methods to measure MEMS properties are usually impractical, expensive, have unknown accuracy and large uncertainty, enabling MEMS to calibrate themselves is a game-changing innovation."

Clark previously developed the self-calibration theory. He and doctoral student Fengyuan Li have now created the device and conducted experiments to validate the theory. Findings are detailed in a paper to appear later this year in the IEEE Journal of Microelectromechanical Systems, or JMEMS.

The peer-reviewed work received a grade of A for "innovation" and an A for "importance to the field," which testifies to the significance of the research, Clark said.

"I think it's important to note that in 1990 MEMS pioneer Richard Muller said research on the mechanical properties of the materials in these devices is needed to provide the engineering base that will make it possible to exploit fully this technology," he said. "And during a 2007 visit to Purdue, physics Nobel laureate John Hall said that without accurate and precise measurements, no reliable form of science or engineering is possible."