Momentum - The Magazine for Virginia Tech Mechanical Engineering Vol. 2 No. 2 Summer 2017 | Page 24

STORY, BY ELEANOR NELSEN
PHOTO, BY TIM SKILES
INSTITUTE FOR CRITICAL TECHNOLOGY AND APPLIED SCIENCE
COLLABORATIVE
EFFORT
VT teams with Korean institutes for
high-performance materials research
Magnetoelectric materials, which convert magnetism to electricity and vice-ver-
sa, are promising for sensors, computer memory, wireless data transmission and
charging, and biomedical tools, such as MRI scanners.
By combining techniques developed in labs halfway around the world from each
other, researchers at Virginia Tech, the Korea Institute of Materials Science (KIMS),
and the Korea Institute of Science and Technology (KIST) have developed a rapid
method for manufacturing these materials that makes them unusually effective.
The research is led by Shashank Priya, the Robert E. Hord Jr. Professor of Me-
chanical Engineering and associate director for research and scholarship at the
Institute for Critical Technology and Applied Science, and Jungho Ryu, principal
researcher at KIMS.
Magnetic fields are readily available from the wires and appliances all around
us: any device or wire that carries an electric current generates a magnetic field
around itself. Priya and Ryu have designed a magnetic material that converts
these ubiquitous magnetic fields into electricity.
The researchers' magnetoelectric material has two components: a magneto-
strictive material that converts a magnetic field into deformation or vibration and
a piezoelectric material that converts deformation or vibration into electricity.
When the two materials are sandwiched together and a magnetic field creates a
mechanical deformation in the magnetostrictive material, it transmits that defor-
mation to the piezoelectric material next door. Electricity is produced as a result.
The effect also works the opposite way, converting electricity to magnetism.
The effectiveness of the conversion process, called interface coupling, measures
the degree to which a change in one material is transmitted to the other one.
“If all the strain that is generated could be transferred to the other side, that
would be perfect coupling,” Priya said.
The better the contact between the two materials at the interface, the better
the coupling.
MOMENTUM SUMMER'17
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