materials science and engineering

A Microscope as a Shovel? UConn Researchers Dig It

excerpted from UConn Today by
Kim Krieger – UConn Communications

Bryan Huey’s lab used the tip of an Atomic Force Microscope (AFM) as a chisel to scrape away the surface of bismuth ferrite and map the electric landscape of the interior. (Image courtesy of the Huey Lab)

Using a familiar tool in a way it was never intended to be used can open up a whole new method to explore materials, report UConn researchers in the Proceedings of the National Academies of Science. Their specific findings could someday create more energy efficient computer chips. But more broadly, their approach should spur scientists worldwide into trying to use this new approach for a wide range of other materials and eventual applications.

Image courtesy of Jack Dumala, Daniel Schwartz, UConn SquaredLabs
Image courtesy of Jack Dumala, UConn SquaredLabs

The research is based on Atomic force microscopes (AFM), which materials scientists and other researchers use to carefully trace an ultra sharp tip across the surface of all kinds of materials. The tip can ‘feel’ where the surface is, and sometimes can also sense properties like electric and magnetic forces emanating from the material. Then, in the same way a farmer methodically drives a plow back and forth or up and down a rolling field, an AFM can scan the hills and valleys at the surface of a material, developing maps of its holes and protrusions, and even its properties, all at length scales a thousand times smaller than a grain of salt.

Unlike the farmer’s plow, AFMs are generally designed to barely touch the surface in order to prevent damage to the sample (churning up the field). But sometimes it happens anyway.

A few years ago, Yasemin Kutes and Justin Luria, graduate student and postdoc members of UConn materials scientist Bryan Huey’s lab, dug into solar cells they were studying. At first thinking this was an irritating mistake, they noticed that the properties of the material looked different from pictures of the original surface alone. That wasn’t too surprising—for materials used in real-world applications, often the surface is actually engineered to have different properties. Yet before, there had simply been no way to measure such underlying properties with the resolution offered by AFM.

In fact, in the 30 years since AFMs were invented, only a handful of groups worldwide have reported such measurements. This was usually either to finely shape a surface, or to map where electricity flows in a part of a computer chip or in a solar cell like at UConn. But another graduate student in Huey’s group, James Steffes, was inspired to take advantage of this discovery for an entirely different class of materials and materials properties. Could he intentionally use the tip of an AFM like the farmer’s plow, progressively digging deeper into the material, and at the same time map the electrical or magnetic properties for deeper and deeper layers of a ‘functional ceramic?’

The answers, as Steffes, Huey, and their colleagues report in the highly competitive journal PNAS, are yes and yes. To demonstrate the approach, they dug into a sample of bismuth ferrite (BiFeO3), which is a room temperature multiferroic provided by project collaborator Ramamoorthy Ramesh of UC Berkeley. Multiferroics are materials that support both electric and magnetic properties at the same time. For example, “BFO” is antiferromagnetic—it responds to magnetic fields, but overall does not exhibit a North or South magnetic pole—and ferroelectric, meaning it has switchable electric polarization. Such ferroelectrics usually comprise tiny ‘domains’ that all have similarly oriented electric fields. Think of a whole bunch of tiny batteries, clusters of which are aligned with their positive terminals pointing in one direction, alongside other clusters pointing another direction. These are very valuable for computer memory, because the computer can flip the domains, ‘writing’ data into the surrounding material. These domains can be fine enough to be serious contenders for replacing the enormous market of thumb drives and other solid state memory that is now in every smartphone, tablet, camera, and most computers.

But when a material scientist “reads” or “writes” such data in BFO, they can normally only see what happens on the surface. Yet they really need to know what lies beneath as well—if that is understood, it might be possible to engineer more efficient computer chips that run faster and use less energy than those available today. That’s a very important goal for society—already ~5% of all energy consumed in the US goes just to running computers.

domains in the bismuth ferrite changed in shape with depth
A new domain. The researchers were able to show how the domains (tiny sections of material with the same electric polarization) in the bismuth ferrite changed in shape with depth. (Image courtesy J. Steffes, B. Huey)

So Steffes, MSE Department Head Huey, and the rest of the team used an AFM tip to meticulously dig through a film of BFO and measure the interior piece by piece. They found they could map the individual domains all the way down, exposing patterns and properties which weren’t always apparent at the surface. Sometimes a domain narrowed with depth until it vanished, or split into a y-shape, or merged with another domain. No one had ever been able to see inside the material in this way before. It was revelatory, like looking at a 3-Dimensional CT scan of a bone for the first time, when you’d only been able to read 2-D x-ray films before.

“The systems we have in the IMS are special in many ways, including one we are now developing to advance Tomographic AFM even further thanks to a $1M grant from the National Science Foundation alongside support from UConn, the School of Engineering, and UConn. But worldwide there are something like 30,000 AFMs already installed. A big fraction of those are going to try Tomographic AFM in 2019 as our community realizes that we have literally just been scratching the surface all this time” predicts Huey. He also thinks more labs will buy AFMs if 3D mapping works for their materials, and some microscope manufacturers in this substantial high-tech industry will shift their focus to volumetric instead of surface scanning.

Steffes, who drove the project for his PhD research, has subsequently graduated from UConn with his PhD and is applying his skills and knowledge at computer chip maker GlobalFoundries. Researchers at Intel, muRata, and others are also intrigued with what the group discovered, as they seek new materials to extend computing and mobile devices beyond the current state of the art. Meanwhile, Huey’s current team of postdoc, graduate, and undergraduate researchers are continuing to use AFMs to dig into all kinds of materials, from concrete to bone to a host of other computer components. Huey says, “Working with academic and corporate partners, we can use our new insight to understand how to better engineer these materials to use less energy, optimize their performance, and improve their reliability and lifetime—those are examples of what Materials Scientists strive to do every day.”

 

State Legislators Visit UConn Innovation Partnership Building

State legislators visit IPB
Legislators view the Titan Themis at the Innovation Partnership Building (IPB) on Dec. 10, 2018. (Peter Morenus/UConn Photo)

Returning and newly elected state legislators met with university officials at the Innovation Partnership Building (IPB) this week to tour the unparalleled facility and to discuss many of UConn’s core research and educational programs. The tour group included Sen.-Elect Dan Champagne, Rep.-Elect Gary Turco, Rep. Chris Ziogas, Rep.-Elect Jason Doucette, and Rep. Greg Haddad.

Pamir Alpay, executive director of the IPB, led the group on a building tour, focusing on key research areas, specialty equipment and how IPB activities impact and support the state’s economic development. Legislators got a firsthand look at the Advanced Characterization Lab, which houses 11 electron microscopes in addition to X-ray equipment and optical microscopes. Pictured above, microscopy specialist Haiyan Tan demonstrated one of the most sophisticated and powerful electron microscopes in the world, the Titan Themis, which is capable of analyzing samples at the atomic level. Read the full UConn Today story.

UConn Partners in $12.5M DOE Research Center on US Nuclear Security

CREDDS
Materials science and engineering graduate student Marco Echeverria (seated) and Rajesh Kumar, postdoctoral researcher in materials science and engineering and the Institute of Materials Science. (UConn Photo)

The U.S. Department of Energy’s National Nuclear Security Administration (DOE/NNSA) has designated four new Centers of Excellence at universities across the nation. The NNSA is the agency behind the Nation’s Stockpile Stewardship Mission (SSM), which works to strengthen the US nuclear security enterprise by advancing relevant areas of science and ensuring a robust pipeline of future nuclear scientists.

Avinash Dongare, associate professor from UConn’s Department of Materials Science and Engineering and the Institute of Materials Science, will serve as one of the principal investigators for one of these new centers, the Center for Research Excellence on Dynamically Deformed Solids (CREDDS), which has received $12.5 million over five years. The CREDDS center is led by Michael Demkowicz of Texas A&M University and also includes the University of Michigan and the University of California Santa Barbara with Amit Misra, chair of materials science and engineering, and Irene Beyerlein serving as the other principal investigators.  Read the full UConn Today story.

Professor S. Pamir Alpay Elected ACerS Fellow

Dr. S. Pamir Alpay accepts ACerS Fellowship Appointment
Dr. S. Pamir Alpay (right) accepts his Fellow of The Society award from the ACerS President Michael Alexander (left) at the Society’s annual banquet.

Materials Science and Engineering’s own Professor S. Pamir Alpay, Executive Director of the Innovation Partnership Building at UConn Tech Park, has been elevated to Fellow status by the American Ceramic Society (ACerS), a great honor and distinguishment given to individuals who have impacted the ceramics engineering industry through scholarship and enterprise.

Professor Alpay was given this honor at the ACerS Annual Honor and Awards Banquet, in Columbus, Ohio in October. His research in ceramics involves multiscale modeling, electrothermic heating and cooling, HVAC systems, dielectrically tunable oxides and other practical applications of ceramic materials.

The ACerS Fellowship is one of the many honors Professor Alpay has been given this year. He was named General Electric Endowed Professor in Advanced Manufacturing by the UConn Board of Trustees for his extensive work with industry partner collaborations and was given The UConn American Association of University Professors 2018 Excellence in Research & Creativity: Career Award for his continued scholastic service.

The MSE Department is proud to call Professor Alpay one of our team.

Professors, Professionals and Students Mingle and Celebrate at MSE Banquet

Students, alumni and faculty of the University of Connecticut Department of Materials Science and Engineering celebrated their, and their peers’ accomplishments at the annual MSE banquet, held at the Alumni Center at the end of the Spring semester.

The event featured speeches, awards and connections between students and their instructors, as well as graduated professionals working within the field of materials sciences. Over two dozen graduate students also joined in, bringing the attendance total to 100. Read the full story from MSE

MSE Banquet 2018

 

 

Dr. S. Pamir Alpay Named Executive Director of UConn Tech Park

Dr. S. Pamir Alpay
Dr. S. Pamir Alpay

UConn’s Innovation Partnership Building (IPB) at the UConn Tech Park has new leadership. Professor of Materials Science and Engineering, Dr. S. Pamir Alpay will serve as Executive Director of the state-of-the-art facility and associated industry partnerships, effective immediately. Dr. Alpay replaces Dr. Radenka Maric, who served in the role until her promotion to Vice President for Research at UConn and UConn Health this past July.

“We are thrilled to have someone with Pamir’s extensive experience as a scientist and collaborator leading the Tech Park,” says Dr. Maric. “Having already worked closely with several of the companies associated with the Tech Park and currently leading the UTAS Center for Advanced Materials which will be housed at the IPB, I am confident that Dr. Alpay will be able to hit the ground running as Executive Director. We are excited to see him build on the progress already achieved by centers located at the IPB, the School of Engineering, and the Institute of Materials Science.” read the full story from the UConn Innovation Portal

High Expectations for 1st Symposium on Computational Research

Postdoctoral researchers from the Institute of Materials Science and the Materials Science and Engineering Department will hold their 1st Symposium on Computational Research on Thursday, July 27. IMS News asked Dr. S. Pamir Alpay, Head of the Materials Science and Engineering Department and postdoctoral researcher, Dr. Sanjeev Nayak, coordinator for the symposium, about their expectations for the first year of the event:

Dr. S. Pamir Alpay
Dr. S. Pamir Alpay

How did the idea of this symposium come about?
As new students joined our group, there was a requirement to introduce them to the field. But, materials science and engineering is such a vast subject covering all the disciplines of STEM, it was desirable to have them see beyond the research interests of the group. Hence, a thought came that we should arrange a symposium. From another perspective, there existed no formal postdoctoral researcher’s activity in the IMS/MSE and we know their important contribution in research. This symposium was planned such that IMS/MSE postdoctoral researchers could take the lead, discuss their research and create an active and brainstorming session. The IMS/MSE postdoctoral members from modeling and theory division voluntarily came forward and hence the symposium touches the theoretical aspect.

What are your expectations for the symposium and what does success look like?
Our expectations for this symposium are at the individual research level. For example, if someone is stuck in a bottleneck situation pertaining to one’s research, it would be easy to seek help from a more experienced researcher in that field. We expect that the students and researchers would make themselves known to one other so that each would know where to find help. Maintaining a list of participants of this (and future) symposium will provide that necessary contact information. Our measure of success is simple, more active engagement with people and a sense of collective academics. The tone of this symposium is at the level of idea-exchange and concept development. If we can set a playground for conceptual development, naturally we would be doing creative research. We are glad that people from departments like, Mechanical Engineering, Chemistry, Physics, Mathematics, Statistics, Computer Sciences, and Electrical and Computer Engineering have signed-up for the symposium.

Dr. Sanjeev Nayak
Dr. Sanjeev Nayak

As this is being billed as the 1st, what are your expectations for future symposia?
We believe that isolated events cannot accomplish the broad goals and hence we encourage annual meetings of this kind. This year’s program is an IMS/MSE postdoctoral activity and attendees have signed up from various departments of UConn and one guest from the Roger Williams University, Rhode Island. We can see that this type of symposium on fundamental research raises a lot of interest among researchers. Our effort for future symposia would be to accommodate selected experts from universities, national labs and industries from across the nation. Such gatherings will help our young members to assimilate, build up networks and possibly also find jobs.