Two UW-Madison College of Engineering professors have been honored with 2015 Romnes Faculty Fellowships, which honor and support promising young faculty at UW-Madison. Electrical and Computer Engineering Professor Irena Knezevic and Materials Science and Engineering Professor Padma Gopalan will each receive an unrestricted $50,000 award for research, supported by the Wisconsin Alumni Research Foundation (WARF). The fellowships will support the researchers as they build upon UW-Madison’s leadership in computing technology and advanced materials.
As the semiconductor industry strives to make smaller and more compact products, it is becoming increasingly important to understand the physical laws on a very small scale. This crucial intersection of electronics, quantum mechanics, and computing is where Knezevic focuses her research. Knezevic explores the physics of how heat, electrical charge, and light travel in the nanoscale environments of computing and laser technology, and how those physics impact a device as a whole.
Recent projects in Knezevic’s group have included developing mathematical modeling tools intended to help laser makers get the most out of the quantum mechanics at work in the technology. “A small segment of the whole laser requires quantum mechanics to describe, and the rest of it is classical. We’re looking at how the laser works as a whole system, how the quantum-mechanics part couples with the entire structure,” Knezevic says.
Knezevic says the Romnes Fellowship funding might help her group convert the code of the laser-modeling work into more accessible tools for industry and other researchers. The funding will also bolster Knezevic’s efforts to contribute to a greater understanding of how near-field electromagnetic radiation interacts with nanoscale systems and how highly disordered, or rough, nanostructures conduct heat.
“This fellowship will help us explore the exciting connection between thermal transport at the nanoscale and quantum chaotic physics in general,” Knezevic says.
Gopalan is planning to use the fellowship’s monetary support to develop research in the field of bioinspired materials design. Bioinspired design of materials focuses on using the natural tenets of the biological world to create and develop material solutions within a variety of fields, including medicine, electronics, and composites.
Gopalan’s group is currently focused on two areas of research: synthesizing new polymers that self-assemble, and developing coating materials. New funding through the Romnes award could open up these areas of expertise to new possibilities and applications, specifically in bioinspired materials design.
Bioinspired materials design brings light to the vast and all-encompassing nature of self-assembly.
“Self-assembly is such a universal concept that it percolates through electronic materials to biomaterial to everything else,” says Gopalan. “Just developing that fundamental understanding in each of those and identifying the relevant problems to answer is quite challenging. That’s why my research is quite diverse if you look at it.”
Gopalan, who conducts research in self-assembly of polymeric materials and polymeric coating, sees bioinspired materials design as an opportunity to bring together the disparate pockets of the engineering world.
“We all have our little corners of expertise,” Gopalan says. “But it’s probably time to pull all of that together, to have a much broader overview of how we can actually mimic these highly complex biological systems, which not only have structural properties, but have very specific biological functions.”
According to Gopalan, bioinspired materials design is a way to make practical use of a wide range of fundamental scientific knowledge, and to design something with a complex, “hierarchical” structure.
She uses the specific example of the iridescent blue color of butterfly wings, where it is the microstructure that leads to the color and not an actual pigment. Likewise an abalone shell is a complex composite, consisting of inorganic minerals as well as organic elements, such as proteins. Gopalan notes that the shell’s mixture of soft and hard materials together creates an incredibly strong structural material. The way these elements interact with each other in nature can establish a platform for creating structurally useful materials across a wide range of modern disciplines.
Many of the structures nature has created—for example, the honeycomb lattice of a honeybee hive—have an inherent harmony that can be mimicked in science. Gopalan specifically looks to the self-assembly process, and how certain systems in nature are driven toward a “minimum energy state.”
“Many of these natural systems, whatever the soup of life that they come from, drive the structural formation to the minimum energy state,” Gopalan says. “What we’re trying to do with synthetic systems is pretty much the same.”
The concept of self-assembly and the driving forces for self-assembly are similar regardless of whether the medium is nature or synthetic systems, such as the various polymers that Gopalan works with. Self-assembly describes the process through which components or molecules arrange themselves in a certain way with or without being stimulated by an outside source.
In addition to future research plans in bioinspired materials and self-assembly, Gopalan has continued to develop a collaborative project with Harvey D. Spangler Professor of Biomedical Engineering William Murphy. The collaboration involves developing a 2D coating material that will provide a stable environment for the differentiation of stem cells into osteoblasts.
This process requires a long-term stable environment that Gopalan and her group have been able to accommodate with certain coating materials.
“We have shown the coatings to be stable in biological and cell culture mediums for over a month, but now we have to take the next step to see if we can actually trigger the stem cells to form bones,” she says. “That’s the next leg of this project that we’re getting into right now.”
Lexy Brodt, Scott Gordon