As manufacturers and researchers reach the limits of silicon’s physical and chemical properties, UVA Engineering’s Multifunctional Materials Integration (MMI) initiative seeks to find more advanced semiconductor materials.
By Charlie Feigenoff
Since the invention of the transistor 50 years ago, advances in computing have been swept along on a river of silicon. As the most common material for semiconductors, silicon has many advantages, not the least of which is its abundance. But at last that stream is beginning to slow as manufacturers and researchers reach the limits of silicon’s physical and chemical properties.
Finding successors for semiconductor materials like silicon and the interfaces between these materials is the goal of UVA Engineering’s Multifunctional Materials Integration (MMI) initiative. Indeed, the purpose of the initiative is not simply to replace standard semiconductor materials and interfaces but to find even better ones that offer higher energy efficiency and as yet unachievable performance and functionality. Such designer materials could set the stage for advances in such varied areas as 5G wireless networks, hardware for the Internet of Things, high-density data storage and artificial vision.
“At UVA, we have expertise, spanning individual departments and schools, to begin reinventing the information age and to take this research from atoms to applications,” said Patrick Hopkins, associate professor of mechanical and aerospace engineering. Hopkins is one of 40 faculty members from a range of disciplines who make up the MMI group. They are engaged in a remarkable, grassroots process of finding common ground, securing funding and launching this University-wide initiative.
A True Grassroots Collaboration
The initiative was inspired by UVA Engineering Dean Craig Benson’s realization that cross-disciplinary collaboration was the key to the gaining the critical mass the Engineering School needs to target pressing, complex societal problems. After hearing each other give presentations at the Engineering School research retreat in 2015, Hopkins and his colleague in Mechanical and Aerospace Engineering, Xiaodong (Chris) Li, Electrical and Computer Engineering Professor Steven Bowers, and Materials Science and Engineering professors Petra Reinke and Leonid Zhigilei realized they could consolidate their proposals into a powerful cross-cutting initiative.
“Advances in new and energy efficient technology cannot be achieved anymore by insular thinking but require cross-disciplinary collaboration,” Reinke said. “The research retreat was an excellent initiation point — an intellectual melting pot of ideas. It became clear to us that we needed to team up and share our vision in a team effort to do impactful work.”
Zhigilei agreed. “A unique characteristic of the MMI initiative is its highly interdisciplinary nature, which pushes us out of the comfort zone of our disciplinary areas of expertise and, at the same time, enables a broad range of very promising collaborative activities,” he said.
As the initiative gained momentum, the researchers were able to home in on a distinct, modular vision of what they wanted to accomplish. In essence, semiconductor devices consist of layers of materials with different properties. The MMI group wished to design tool sets consisting of newly designed advanced materials and interfaces. They would then combine these elements to create devices, which in turn could be integrated in novel ways to form systems with revolutionary properties.
The goal of the initiative is to exploit every opportunity to sidestep the tradeoffs that limit the usefulness of existing materials and interfaces and that constrain breakthroughs in design. Multifunctional Materials Integration faculty members envision applications that are not grounded in a particular domain, but can measure and control electricity, heat, light, magnetics, charge and electron spin simultaneously.
A Supportive Institutional Environment for Crosscutting Research
As the initiative gained focus and momentum, its members realized that there were gaps in the expertise on Grounds needed to realize the vision. Four of the Engineering School’s new faculty members last year joined the Multifunctional Materials Integration group, and three faculty have been hired so far to join the initiative during the 2017-18 academic year: Jon Ihlefeld, who will be jointly appointed to the Materials Science & Engineering and Charles L. Brown Electrical & Computer Engineering departments; Nikhil Shukla, who will be jointly appointed to the Electrical & Computer Engineering and Materials Science & Engineering departments; and Yi Xu, with a joint appointment in Electrical & Computer Engineering and UVA’s Department of Physics.
Furthermore, as faculty members from the College of Arts and Sciences and the School of Medicine joined the MMI initiative, the conversation expanded to include a list of critical voids beyond UVA Engineering. “Hiring across the University could take MMI to an entirely new level,” Hopkins said.
The University also recognized the potential of this initiative. It recently allocated $9.1 million for a comprehensive renovation and redesign of the University of Virginia Microfabrication Laboratory (UVML), which includes a 3,500 square-foot clean room. A group of MMI faculty members led by Arthur Lichtenberger, director of the UVML, also competed successfully for a $10M University Strategic Investment Fund (SIF) grant for a suite of state-of-the-art tools for the UVML and two other pan-University facilities that support this research. These are the Nanoscale Materials Characterization Facility and Far Infrared Terahertz Laboratory.
“This suite of major equipment is critical to providing the transformational facilities required to be a key international player in the field,” Lichtenberger said. “It will enable us to drive the disruptive MMI technological advances with high visibility and deeply significant societal impact.”
For Steven Bowers, the electrical and computer engineering professor who was one of the founding members of the MMI group, the mixture of grassroots development and top-down support will be vital to the initiative’s success. “I think this kind of synergy where you simultaneously have technical ideas and collaborations coming from the faculty and supporting resources being provided from the top levels of a university is quite rare,” Bowers said. “It makes this initiative very special.”
The Next Step
As Hopkins points out, MMI has become large enough that it can no longer function effectively on an ad hoc basis. “We see many opportunities coming out of MMI for securing major center-level grants,” he said. “To prioritize and seize these opportunities, we need to have an organizational structure.”
The group is also considering the creation of an interdisciplinary curriculum for undergraduates built around MMI. As materials scientist Leonid Zhigilei said, “Not only does the MMI Initiative open up new opportunities for attracting externally-funded research projects to the Engineering School and the University, but it also creates a practically relevant educational environment for our students.”
What the MMI initiative has accomplished to-date is impressive. Already discussions among MMI faculty have generated almost a dozen collaborative grant proposals in areas as diverse as 2-D materials interfaces and laser-based nanomanufacturing.
For Bowers, the MMI initiative has been a wonderful opportunity. “As an assistant professor who is just starting out, I have been able to interact and learn from a wide range of researchers from different departments,” he said. “In a traditional school with large departmental boundaries, this would have taken me years.”