An assistant professor at South Dakota School of Mines and Technology has made a new discovery in nanoparticle research that could benefit engineering, medicine, computing and more.
Shan Zhou works in the Department of Nanoscience and Biomedical Engineering at SDSMT. He found a way to make self-assembling nanopyramid structures that can change their shape and configuration through different chemical treatments. He initially made the discovery during his post-doctorate research at the University of Illinois.
"We first discovered … (these) pyramid-shape nanoparticles that tend to come together,” he said. “And we added some chemicals in the solution to play around (with) the condition a little bit, and we magically found that these nanoparticles can form into these pinwheel-shaped units.”
The structures are made out of metamaterials, which are materials not found in nature. These metamaterials can take on different functions depending on their structural configuration, and Zhou’s research focuses on using different chemical solutions to change the structure of a single metamaterial.
Zhou’s pinwheel structures also demonstrate an impressive feat in nanoscience: chirality. A chiral structure is something that cannot be mirrored perfectly onto another nanostructure of the same shape. Zhou likened it to the way our hands mirror each other.
"If we take a mirror image of your left hand, it happens to be exactly the same as your right hand,” he said. “But if you look at both of your hands, you cannot overlap with them, so if you line your fingers, they have to face in opposite directions.”
Chirality is found frequently in nature but is difficult to create in an artificial structure, since most nanostructures tend to form symmetric patterns instead, which are difficult to break.
Zhou, who came to SDSMT in 2022, is the lead author on this research. It was recently published in Nature, a renowned multidisciplinary science journal. Research teams from the University of Illinois and the University of Michigan also contributed to the findings.
Zhou said the research could benefit future engineering or computing projects because of the versatility of the design and its ability to change shape. These nanostructures could be used in combat helmets, airplanes and machine vision, which allows computers to “see,” such as in self-driving cars.
He also said the particles could be used in biomedical research, too.
“We can also design smart biosensors, because our structure is tunable, or reconfigurable,” he said. “It might be able to detect different types of virals or biomolecules, depending on how we design the structure.”
The next step of this research is to try and recreate the structures on a larger scale, with the goal being structures measuring in centimeters or more.
Along with his nanoscience research, Zhou works with microscopy studies to study nanostructures using high-resolution microscopes.
He added he welcomes any interested students to reach out to him to talk about his research.
“Contact me, and especially for local high school students, if they want to do a summer project, something like that, we have plenty of opportunities for that,” he said.
