Big vision for tiny particles: Dr. Mahua Biswas creates building blocks of future tech in nano lab

You don’t need a microscope to grasp the enormous impact of nanotechnology on our daily lives.

“It’s the reason why a new phone is sleeker, smaller, and more efficient,” said Dr. Mahua Biswas, Illinois State University assistant professor of Physics. “It’s the future—nanometer scale materials provide superior optical and electrical properties compared to their bulk versions.”

Biswas is fabricating these nanoscale patterned materials as building blocks for futuristic technology—thousands of times smaller than the width of a human hair follicle—through an innovative and tedious process using an atomic layer deposition tool, a spin coater, a centrifuge, and furnaces, among other tools. In her Moulton Hall laboratory, Biswas and her undergraduate student research group whip up inorganic nanostructures and nanopatterns derived from various nanostructured polymers, a substance commonly known as plastics.

The researchers meticulously document the fabrication process and the characteristics of their newly created structures, which have the potential to be utilized in emerging applications such as compact circuit boards, data storage devices, and solar cells. For specialized analysis, Biswas and her students visit Argonne National Laboratory, one of the largest federal research facilities near Chicago, where Biswas is a visiting research scientist.

“It’s like a race right now for achieving better technologies,” Biswas said. “Those of us in the nanotechnology field are always trying to improve by experimenting with new materials, and we want to make the technologies we’re already using even better.”

As an undergraduate electronic engineering major in India, Biswas was drawn to the physics of semiconductor sciences and devices. “It’s the basis of all electronic devices—like transistor diodes,” Biswas said. “You really need to understand the physics well and know about the materials used to make semiconductor devices. That was the part that I loved.”

After spending one year working for an engineering firm, Biswas left to pursue a Ph.D. in Ireland where her supervisor was researching semiconductor physics involving zinc oxide nanostructures.

“In 2006, zinc oxide was considered as one of the most promising materials for the future semiconductor industry,” Biswas said. “The cherry on top was I was introduced to nanostructures of zinc oxide which shows superior optical properties.”

In collaboration with her supervisor, Biswas created nanostructured zinc oxide and studied the optical behavior of the material. She moved to the U.S. for postdoctoral work at the New Jersey Institute of Technology and Argonne National Laboratory before joining the faculty ranks. In fall 2020, she arrived at Illinois State.

“This job really gave me what I was searching for, because in our department, the teaching and research balance is really good,” Biswas said. “All of us in the department are doing cutting-edge research, and that is also part of the student development process because students need to get that exposure.”

Last spring, Biswas earned Illinois State a $179,285 National Science Foundation (NSF) LEAPS-MPS grant to research nanostructures made of nitrides using a process called sequential infiltration synthesis (SIS). She and her research group will attempt to become the first to successfully develop nanopatterns of nitrides using polymer as templates.

“All the research already happening with nitrides nanopattern growth involves high temperatures,” Biswas said. “Let’s say you want to make an LED (light-emitting diode). A nitride is a very good LED material. You’ll want to make it on a substrate, which is flexible—most likely polymer, a plastic. That’s very difficult currently, because the current methods the industry is using for growing nitrides need a high temperature, which isn’t compatible with any soft substrates like polymers.” This is just one aspect of the difficulties in utilizing small-scale nitride materials for emerging technologies.

Using a low-temperature method, the Biswas group will deposit nitride into a template made of nanopatterned polymer. “Not many groups are doing low-temperature nitride growth because it’s very difficult to do, but that’s the challenge we are taking on,” Biswas said. “In my proposal, I showed why I think it’s possible.”

The Biswas group will be aided in its research by a state-of-the-art electron microscope purchased through an NSF grant (see sidebar) for which Biswas served as the principal investigator. Known as a field emission scanning electron microscope (FESEM), the instrument takes images of nano-sized objects and enables users to detect intimate details and properties.

“We used to have to travel to Urbana-Champaign to image our samples, which is not at all productive,” Biswas said. “Now, we can make something, go to the next room to image it, and see, ‘OK, this is not working, let’s try the next condition.’ So that’s a huge thing in terms of productivity and student involvement.”

Undergraduate students have played a significant role in Biswas’ lab. During summer 2021, physics students Amelia Korveziroska and Marcos Perez ’22 drove to campus nearly every weekend to make silicon nanoparticles for a project sponsored by an Office of Student Research undergraduate grant.

Their samples were initially characterized under an optical beam in Associate Professor of Physics Dr. Uttam Manna’s lab and sent to University of Chicago researchers who are studying optical trapping. Perez likened the concept of trapping to a science fiction movie.

“You know how they have tractor beams that can lift someone off the ground into the UFO? So, you can basically make tractor beams but for really small things,” Perez said. “You can make light move physical objects.”

University of Chicago researchers use lasers in their efforts to trap and manipulate nanoparticles, including those created by Korveziroska and Perez. Biswas said they are in the process of writing a manuscript on that work.

“From day one, these two students were really motivated,” Biswas said. “They wanted to do it. Now, you look at how much they are doing and how much they are contributing.”

Perez and Korveziroska co-authored an article with Biswas that appeared in the Journal of Applied Physics. They have also presented their research at the American Physical Society conference and the American Chemical Society conference, both in Chicago.

“Actually being here in the lab, papers being published, and the possibility that things I’ve made could maybe one day influence tomorrow—sometimes it’s amazing to think about,” said Korveziroska, a junior physics engineering major who aspires to work for NASA. Over the summer, she participated in a Research Experiences for Undergraduates (REU) program at the Harvard-Smithsonian Center for Astrophysics.

Biswas credits Perez and Korveziroska for helping her establish Illinois State’s nanomaterials lab, which she aims to grow with her NSF grant.

“I would like to have a vibrant experimental research group for a really long time in the department,” Biswas said. “Students will get exposed to this research. And for doing that, I always need to come up with new research ideas to keep getting funding to do these projects and to continue successfully publishing papers.”

Staying steps ahead of cutting-edge technology pushes Biswas to envision the future. Her previous work with sequential infiltration synthesis to make nano patterns for magnetic materials was utilized in developing Western Digital memory storage devices.

“But the early-stage research we’re doing now is considered as the fundamental research for developing a technology,” Biswas said. “The device you have right now—scientists did research for that decades earlier. So, the research we’re doing now—you’ll probably see the result in another 20 years.

“That’s what we do as fundamental researchers. We try everything, and then we give the best to industry.”

And that nanotechnology, the best of the best, perhaps produced in Biswas’s lab might end up in your pocket someday.

Magnifying research

Nanoparticles are so tiny that a specialized electron microscope is required for magnification. Until now, that involved compiling samples at Illinois State University and driving an hour off campus to perform an analysis.

Thanks to a $403,900 National Science Foundation grant for which Illinois State Assistant Professor of Physics Dr. Mahua Biswas was the principal investigator, the once-lengthy trip has been shortened to a quick walk. Planned to be installed in Moulton Hall, a state-of-the-art field emission scanning electron microscope (FESEM) takes images of nano-sized objects of different kinds and magnifies otherwise undetectable details and properties.

Research possibilities reach across fields for students and faculty, with the following units planning on utilizing the electron microscope: Department of Physics; Department of Chemistry; School of Biological Sciences; Department of Geography, Geology, and the Environment; Department of Technology; and University Galleries.

“This grant will change the long-term future of research on campus across departments,” Biswas said.

As students are trained on the FESEM, they will be empowered to take further ownership of their research projects. Biswas said she is also in contact with local educators interested in utilizing the electron microscope to expand learning opportunities for K–12 students.