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.”


Artificial Skin Could Give Superhuman Perception

Islam Mosa James Rusling Abdelsalam Ahmed
Left to right: Islam Mosa, James Rusling, Abdelsalam Ahmed

A new type of sensor could lead to artificial skin that someday helps burn victims ‘feel’ and safeguards the rest of us, University of Connecticut researchers suggest in a forthcoming paper in Advanced Materials.

Our skin’s ability to perceive pressure, heat, cold and vibration is a critical safety function that most people take for granted. But burn victims, those with prosthetic limbs, and others who have lost skin sensitivity for one reason or another, can’t take it for granted, and often injure themselves unintentionally.

Chemists Islam Mosa from UConn, and James Rusling from UConn and UConn Health, along with University of Toronto engineer Abdelsalam Ahmed, wanted to create a sensor that can mimic the sensing properties of skin. Such a sensor would need to be able to detect pressure, temperature and vibration. But perhaps it could do other things too, the researchers thought.

“It would be very cool if it had abilities human skin does not; for example, the ability to detect magnetic fields, sound waves, and abnormal behaviors,” said Mosa.

Read the full UConn Today story

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

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.

UConn, UMass Lowell, Georgia Tech to Collaborate with Industry on 3D Printing Research Supported by NSF

Polymeric structures febricated using 3D printing
Multi-material micro-lattice polymeric structures fabricated using 3D printing. (Kavin Kowsari/UConn Photo)

UConn, the University of Massachusetts Lowell (UMass Lowell), and Georgia Institute of Technology (Georgia Tech) announced a collaboration to establish SHAP3D, a National Science Foundation (NSF) Industry-University Cooperative Research Center (IUCRC), to address emerging challenges of additive manufacturing, also commonly referred to as 3D printing.

IUCRCs bridge the gap between early academic research and commercial readiness, supporting use-inspired research leading to new knowledge, technological capabilities and downstream commercial applications of these technologies.

“This Center will address the grand challenges that prevent the entire 3D printing field from moving forward,” says Joey Mead, Distinguished University Professor and David and Frances Pernick Nanotechnology Professor in the Department of Plastics Engineering at UMass Lowell. Mead serves as the center director of the Center for Science of Heterogeneous Additive Printing of 3D Materials (SHAP3D).  Read the full UConn Today story.

Meet Garvit Agarwal, 2018 Graduate Student of The Year

Garvit Agarwal is a Ph.D. student studying atomistic and mesoscale modeling of dynamic defect structure evolution during high strain rate loading. He is the recipient of the 2018 Graduate Student of the Year Award, for his exceptional work and dedication to the field of materials science and academic excellence since he joined us in 2014.

“I feel really honored to win the graduate student of the year award,” Garvit said. “I am extremely thankful to my adviser, Dr. Dongare, who not only gave me the opportunity to work on the novel research project but also constantly guided me and taught me a lot of things during the past four years of my graduate career at UConn.”

Associate Professor Avinash Dongare, Garvit’s advisor, said Garvit’s passion and work ethic helped contribute to his accomplishments.

“It’s great to see Garvit mature and grow as a researcher over the last four years,” Dr. Dongare said. “He is very passionate about learning new skills and is keen to put in the hard work required. It is very important for students to get as much exposure as possible while they are still in graduate school and Garvit is certainly making the most of it. His hard work and perseverance has opened up a lot of opportunities for my group to collaborate, and he is a leading researcher in the making. He certainly deserves the Graduate Student of the Year Award.”  Read the full MSE story.

Dr. Cato Laurencin Gives Plenary Lecture at MS&T 18 Conference

Dr. Cato Laurencin Plenary Session at MS&T 18
Dr. Cato Laurencin spoke at MS&T 18 about new avenues for regenerative engineering using MSE principles and new technology.

Dr. Cato T. Laurencin, the University of Connecticut’s 8th University Professor in school history and Professor of Materials Science and Engineering gave the American Ceramic Society’s Edward Orton Jr. Memorial Lecture at the 2018 Materials Science & Technology Conference on October 16. His presentation led the Plenary Session for the scientific meeting.

The prestigious Orton Lecture, which is given by an individual with national recognition in their field, is named in honor of General Edward Orton, Jr., founder of the American Ceramic Society. Laurencin, who is a pioneering expert in the field of regenerative engineering, gave a speech entitled “Regenerative Engineering: Materials in Convergence.”

In the lecture, Laurencin spoke about how different materials, including ceramics, in conjunction with new technologies, are leading to major advances in regenerative engineering:

“Polymer and polymer-ceramic systems can be utilized for the regeneration of bone. Novel systems using graphene-ceramics provide new possibilities for bone regeneration. Hybrid matrices possessing micro and nano-architecture can create advantageous systems for regeneration, while the use of classic principles of materials science and engineering can lead to the development of three dimensional systems suitable for functional regeneration of tissues of the knee,” Laurencin said.  Read the full UConn Today story.

Governor Malloy Visits UConn/REA Resource Recovery Systems Project

Gov. Dannel Malloy, Dr. Richard Parnas, and student Dylan Ramirez
(l-r) Gov. Dannel Malloy, Dr. Richard Parnas, and student Dylan Ramirez

Dr. Richard Parnas of the IMS Polymer Program enjoyed a visit from Governor Dannel Malloy to the site of UConn’s collaborative project with the Greater New Haven Water Pollution Control Authority and REA Resource Recovery Systems LLC on September 27, 2018.

The visit celebrated the first milestone of the project, where the brown grease waste stream from the East Shore wastewater treatment plant is converted to biodiesel fuel in a process patented by Dr. Parnas and which REA licenses from UConn. Dr. Parnas and REA installed a mini-refinery at the East Shore treatment plant with capability to produce approximately 400,000 liters per year of biodiesel fuel from the brown grease.

That system serves as a 1/10 scale demonstration of a typical commercial system the company can install at many of the thousands of wastewater treatment plants throughout the world. For ease of installation, the entire demonstration system was constructed inside of 2 CONEX shipping containers at ProFlow, Inc. of North Haven, CT. Future plans include the installation of a turbo-electric generator to demonstrate a pathway to converting the waste stream to power at a cost much less then required with current biodigester technology.  Read the full story from Westfair Communications.

George Rossetti Article on Piezoelectric Ceramics Featured in August 2018 MRS Bulletin

August 2018 MRS BulletinMSE professor Dr. George A. Rossetti, Jr., in collaboration with Dr. Dragan Damjanovic (Swiss Federal Institute of Technology in Lausanne), has published an article in the August 2018 issue of the Materials Research Society (MRS) Bulletin. The paper, “Strain Generation and Energy-Conversion Mechanisms in Lead-Based and Lead-Free Piezoceramics,” analyzes the origins of piezoelectric activity in technologically important ceramic materials used as actuators and sensors. Concepts discussed in the paper are featured on the journal cover.

Piezoelectric ceramics (piezoceramics) convert electrical into mechanical energy, and vice-versa. They are found in many products encountered in everyday life, including spark igniters, buzzers, ultrasonic cleaners, inkjet printers, fuel injectors and medical ultrasound diagnostic equipment, just to name a few. They are also vital to the sonar systems used in submarines and other undersea vehicles.

For over 60 years, the most important piezoceramic materials have been based on the ferroelectric solid solution lead zirconate-titanate (Pb[Zr1-xTix]O3or PZT). About 15 years ago, however, legislation in Europe and elsewhere restricting the use of lead-containing materials in electronics triggered an effort to find lead-free piezoceramics that could replace PZT in many, if not all, applications. Read the full MSE story.