Crystalline alloy boosts piezo MEMS operation
11/30/2011 8:36 AM EST
MANHASSET, NY -- Researchers have successfully integrated a new, highly efficient piezoelectric material into a silicon microelectromechanical system.
A large research team led by scientists from the University of Wisconsin-Madison developed a way to incorporate PMN-PT into cantilevers on a silicon base for MEMS construction.
The researchers demonstrated that a crystalline alloy of lead, magnesium niobate and lead titanate could deliver two to four times more movement with stronger force using only 3 volts than most rival materials studied to date.
The PMN-PT material also generates a similarly strong electric charge when compressed, which is advantageous in sensing and energy harvesting applications.
To confirm that the experimental observations were due to the piezoelectric's performance, NIST (National Institute of Standards and Technology) researcher Vladimir Aksyuk developed engineering models of the cantilevers to estimate how much they would bend and at what voltage. Aksyuk also made other performance measures in comparison to silicon systems that achieve similar effects using electrostatic attraction.
"Silicon is good for these systems, but it is passive and can only move if heated or using electrostatics, which requires high voltage or large dissipated power," said Aksyuk. "Our work shows definitively that the addition of PMN-PT to MEMS designed for sensing or as energy harvesters will provide a tremendous boost to their sensitivity and efficiency."
Other researchers included scientists from Penn State University; the University of California, Berkeley; the University of Michigan; Cornell University; and Argonne National Laboratory.
The research work “Giant piezoelectricity on Si for hyperactive MEMS” appears in the November 18 issue of Science.