Dr. Marian Gidea, who directs the graduate programs in mathematics at the Katz School, collaborated with Tamar Leiser, who wrote her honor’s thesis on piezoelectricity as a student at ’s Stern School for Women, and Katz School Mathematics Ph.D. student Samuel Akingbade.

By Dave DeFusco

At a recent presentation at the prestigious International Congress of Industrial and Applied Mathematics in Tokyo, Dr. Marian Gidea, association dean for STEM research and director of graduate mathematics at the Katz School, revealed the results of a simplified mathematical model demonstrating that oscillating steel beams made of piezoelectric materials produce more energy when their motion is regular.

The research, "," is supported by a three-year $300,000 National Science Foundation grant, which was awarded in July to investigate dynamical systems, including applications to energy harvesting, celestial mechanics and space mission design. 

Piezo is the Greek root for pressure or push, and piezoelectric describes a property of special solid materials that can convert energy from an applied pressure into an electrical charge.

The computer model was developed in collaboration with Tamar Leiser, who wrote her honor’s thesis on the subject as a student at ’s Stern School for Women, and Katz School Mathematics Ph.D. student Samuel Akingbade, as well as research collaborators from Georgia Tech and Polytechnic University of Catalunya.

The researchers created a framework in which two steel beams are hooked up to a capacitor and suspended over magnets. When the vibration of the beams is stronger than the mechanical friction, electricity is produced and stored in the capacitor.

“What we discovered to our surprise is that the answer we got was the one we should have expected,” said Dr. Gidea. “The beams that keep moving in a regular fashion, a periodic motion, going back and forth, accumulate more energy in comparison with the ones that move chaotically—that is, without any pattern.”

Energy harvesting devices, which produce electrical charges through external vibrations, can be attached to skyscrapers, trains or bridges and provide a source of unlimited renewable energy. Piezoelectric energy harvesting is also the preferred method for use with wearable devices since it is the most capable of producing the power needed at a small scale.

The steel beams in the Katz School model were coated with ceramic, the preferred material for this type of energy harvesting because of its low cost and effective piezoelectric properties. The use of piezoelectricity stands to reduce, or even eliminate, the need for frequent charging of devices and batteries. Consumers would no longer be burdened with having to be near an electrical outlet, which would in turn conserve electricity.

“This may be a critical advance for healthcare since these devices can be implanted in pacemakers to stimulate the heart,” said Dr. Gidea.