SU uses $1.4 million grant for Piezoelectric Research

A research project on piezoelectric materials has resulted from combining conventional approaches with creative methods in the Department of Physics at Southern University.
The research project is being conducted in the Electronic Materials Research Laboratory (EMRL) that was established for a piezoelectric research project in the department in 1996. The project is supported by a $1.4 million grant from the Office of Naval Research. Out of this amount, $200,000 is the indirect cost to SU.
Piezoelectric materials, such as barium titanate, can change electrical properties when pressure is applied on them. Ferroelectric is a kind of piezoelectric material that has extraordinarily high dielectric constant. Ferroelectrics are extensively used to fabricate capacitors, the key electronic component in television sets, computers and other electronic instrument.
“In modern technology, miniaturizing and keeping high efficiency of a device is a key factor that determines its feasibility and applicability. Among other electronic constituents in an electronic device, capacitor is one of the most important components in any such device,” said Dr. J. T. Wang, the project’s director.
Dielectric constant is, in turn, the crucial factor to determine the size of capacitor. And searching for the materials with high dielectric constant is one of the research goals, Wang said.
According to Wang, the objectives of the project are: to search for new ferroelectric-piezoelectric materials; to find the means to improve the function of existing materials for naval and civil applications; to provide update research topics to the students.
“Piezoelectric materials have characters that can convert mechanical energy into electrical energy, and vice versa. Therefore, they are essentially for building transducers: sensors and actuators,” said Chen Zhang, a postdoctoral fellow working in EMRL
Zhang gave an example that acoustic wave (mechanical energy) can turn into electrical oscillation (electrical energy) through sensors. On the other hand, an electrical signal can turn into mechanical motion (mechanical energy) such as acoustic wave or other mechanical action through an actuator.
“Both sensors and actuators have very wide application in the modern technologies,” Zhang said.
Wang also stated that the Navy particularly needs this technology.
“As you know that in air radar is a powerful tool to gain navigation information. Under water, however, is another story, because electromagnetic wave cannot penetrate water. Acoustic detection may be the only mean to accomplish the job,” Wang said.
According to Wang, piezoelectric devices can detect very weak signal under water from a distance away, that is sensing and also it can generate acoustic wave (sonar) to propagate in the water for a long distance.
Zhang said that when the wave impacts the object, it can reflect back and be detected. The detected signal carries information that we need. The ultrasonic medical diagnosis device is also based on the same principles. The materials have many other applications in remote control, night vision, medical diagnosis, smart materials and optical telecommunications.
“As far as to search for better piezoelectric materials concerned, element substitution is one of the main techniques to find a good composition,” Zhang added.
The project research has succeeded in finding some new materials with improvement dielectric properties of a kind of new materials while its productions cost is lowered.
“Some materials manufacture companies have expressed their interest in our research results, because of this feature of the new materials,” Wang said.
Wang and his co-workers have had more than 20 peer-viewed papers have been published in various journals. They have also presented their research works in many national and international conferences on behalf of Southern University.
More than 25 students have done excellent research in this project. Manfor Chinkhota, an undergraduate student major in ceramics, was awarded first and forth places for his presentations on his research work under this project at two conferences in 2001 and 2002, separately.
The research project collaborates with Pennsylvania State University, Temple University’s Center for Advanced Microstructure and Devices, Louisiana State University (CAMD-LSU), the Chinese Academy of Sciences, Beijing University of Sciences and Technology, and Xiamen University in China.
Wang said for the EMRL at SU to go further steps in research on electronic materials, an X-Ray diffraction meter that is an essential tool for materials research will be set up in the lab.
“This machine might further enhance the research activities of faculty and students university-wise,” he said.