K. Andre Mkhoyan From soccer balls to atomic-scale structures
There are special rooms for the instruments that K. Andre Mkhoyan uses. The walls are padded to dampen acoustic vibrations, the air is cooled so temperatures never vary more than one to two degrees, and the floors are concrete to lessen any sudden human movements or unexpected seismic activity.
Mkhoyan, the Ray D. and Mary T. Johnson/Mayon Plastics Chair in CSE’s Department of Chemical Engineering and Materials Science, specializes in advanced transmission electron microscopy (TEM). Instead of using visible light, his microscopes are capable of producing high-resolution images of a specimen with a beam of electrons—and at magnifications of up to 10 million times what the unassisted eye can see.
“To see human hair very nicely, you will need about 1,000 times magnification because human hair is about 75 microns or 75,000 nanometers,” he explained. “One nanometer is a billionth of a meter or one millionth of a millimeter. In my research, we want one level higher. We want to go to the atomic scale, which is 10 times higher than nanometer.” In other words, Mkhoyan can really see the flaws that could compromise the integrity of a structure. Finding these discrepancies, or defects, in commonly used materials is one direction that really excites him today. Why? Because what makes one material more desirable versus another depends on its properties.
“Let’s say you have a piece of metal and it has a crack or some holes on it,” he explained. “Now, imagine those defects inside the metal. Every material has plenty of them on an atomic level. What this means is some atoms are missing or they may be in the wrong position. Knowing where those defects are allows us to better understand their role or sometimes take advantage of them. We can use a defect as a way to improve the material.”
Recently, his research team was the first to observe metallic lines in a crystal. The discovery is significant because it could lead to even more smart devices and windows, ones that have a touch-sensitive surface, are transparent to light and conduct electricity.
“We need to understand what a material looks like first to help drive technology,” said the Armenian-born Mkhoyan, who joined the University of Minnesota in 2008. “I always like to look at defects as spices in the food. If you sprinkle the right amount of the defects into a new structure, like spices into your soup or meal, it will give you all of the flavor you need or the functional properties you want.”
Arriving at his current career wasn’t easy. Mkhoyan spent a whole summer in his early teens “meditating on” whether to pursue his dreams of becoming a soccer player or a scientist.
“I needed to choose one or the other because there was a really good boarding school for physics and math on the other end of town,” he recalled, “and it was absolutely incompatible with soccer.”
His decision eventually led to graduate school in the United States and his first full-time job as a physicist at Bell Labs, in Murray Hill, N.J., where he was introduced to TEM. “Nanotechnology was starting to be a really important topic and I really enjoyed that type of science,” he said. “I also always had a fascination with photography. So it felt like a good idea then to combine both my joys in life and make a career out of it.”
Mkhoyan—who hasn’t missed a World Cup soccer final in 30 years—oversaw the 2014 renovation of his lab in the University of Minnesota’s Characterization Facility. His role included securing funding and designing the rooms to hold key instruments, which are available to anyone whose work spans from nanotechnology to medicine.
However, advanced microscopes are complicated instruments. Mkhoyan said some take one month to learn; others, half a year or a year to use properly. “I think it’s fair to say Minnesota is one of the most well-equipped in electron microscopes,” he said. “There are not that many universities that can say that. We are definitely on the forefront of this type of research and facility.”
-Published in the University of Minnesota College of Science and Engineering Inventing Tomorrow Magazine (Fall 2021)