By Liz Sheeley
Professor Xin Zhang (ME, MSE, ECE, BME), recipient of the 2018 Charles DeLisi Award and Distinguished Lecture, presented “Tailoring Electromagnetic and Acoustic Waves with MEMS and Metamaterials” on April 12. The award recognizes faculty members with extraordinary records of well-cited scholarship and outstanding alumni who have invented and mentored transformative technologies that impact quality of life.
Zhang began her talk by describing microelectromechanical systems (MEMS)—depending on her audience she explains MEMS with different analogies from a car to a phone to elements of biology. MEMS integrates mechanical elements, sensors, actuators, and electronics onto a common silicon chip through microfabrication technology.
“I have three MEMS research platforms that are all driven by important real-world applications such as sensors for harsh environments, biosensing on a cellular level, and infrared detectors,” said Zhang. The talk focused on the photonics and optical applications of MEMS.
Zhang uses metamaterials to develop sensors and actuators with novel features. These materials are synthetic composites of tiny structures that can exhibit properties that natural materials cannot. Researchers can fill holes for specific needs by designing their own “material” and thus create devices with novel capabilities.
Metamaterials are used to affect waves of sound, light and electromagnetic radiation such as microwaves. “Their unique property lies in their structure and not in their chemical composition so with the proper design at a certain frequency you could gain properties like negative refraction,” said Zhang. “With this kind of artificial material we can focus light and create phenomena not possible with natural materials such as cloaking or invisibility.”
These materials can lead to tuning sound waves to focus them on specific areas or to specific people. If three people are in a room and only one wants to watch TV, the sound waves could be focused to only that specific person and only let them hear the TV.
“In addition to using metamaterials for research, I wanted to discuss the various applications of metamaterials for what society needs,” said Zhang. “I think that’s the mission of engineering.”
The DeLisi Lecture continues the College’s annual Distinguished Lecture Series, initiated in 2008, which has honored several senior faculty members. The previous recipients are Professor Joyce Y. Wong (BME, MSE), Professors John Baillieul, (ME,SE), Malvin Teich (ECE) (Emeritus), Irving Bigio (BME), Theodore Moustakas (ECE, MSE), H. Steven Colburn (BME), Thomas Bifano (ME, MSE), Christos Cassandras (ECE, SE), Mark Grinstaff (BME, MSE, Chemistry, MED) and M. Selim Ünlü (ECE, BME, MSE).
Widely considered the father of the Human Genome Project, DeLisi was an early pioneer in computational molecular biology, and also made seminal contributions to theoretical and mathematical immunology. He currently serves as Metcalf Professor of Science and Engineering, and continues to direct the Biomolecular Systems Laboratory, where more than 100 undergraduate, graduate and post-doctoral students have trained.
As Dean of the College of Engineering from 1990 to 2000, he recruited leading researchers in biomedical, manufacturing, aerospace and mechanical engineering, photonics and other engineering fields, establishing a research infrastructure that ultimately propelled the College into the top ranks of engineering graduate programs. In 1999 he founded—and then chaired for more than a decade—BU’s Bioinformatics Program, the first such program in the nation.