Intricate movements of tiny pieces of matter hold key to engineering innovation
Enhancing visualization of nanoparticle dynamics on materials’ surfaces opens paths to high-tech progress
Use of an advanced in situ electron microscope that enables atoms within nanoparticles to be closely observed under a wide range of conditions is aiding research led by Professor Peter Crozier to explore ways to improve materials used in many engineering and related technological applications. Standing with Crozier (second from left) in an Arizona State University microscopy facility are others involved in the research, material science and engineering doctoral students Yifan Wang (far left) and Blake Dorame (far right), along with doctoral student Mai Tan (sitting at left) and Piyush Haluai (sitting at right), a research engineer in ASU’s Eyring Materials Center. Photographer: Yifan Wang./caption]
How nanomaterials form, develop and hold up in stressful environments associated with working conditions in technological projects indicates their suitability, or lack of it, for engineering fields, such as catalysis and many other technology-based applications.
In technological applications such as catalysis, nanoparticles may change their form and structure during exposure to extreme heat, intense light, gases, liquids, electrical current and other kinds of stimuli.
These microscopic particles, each often consisting of a few hundred atoms, have unique properties due to their high surface area to volume ratio.
Being able to see the structural responses at the atomic level — each of which occurs at the millisecond time scale or even faster — reveals the ever-evolving changes in nanoparticles that can demonstrate possibilities for these materials’ uses in many new and existing technologies.
That’s why Peter Crozier is enthused about advances in electron microscopy that can enable closer looks at what atoms are doing in materials.
Illuminating paths to producing stronger materials
Crozier is a professor of materials science and engineering in the School for Engineering of Matter, Transport and Energy, part of the Ira A. Fulton Schools of Engineering at Arizona State University. He has been working for decades to apply new advances in transmission electron microscopy to overcoming challenges to the productive use of electrolytes and catalytic materials.
Electrolytes are substances that conduct electricity through the movement of ions instead of electrons. Catalytic materials accelerate chemical reactions without being consumed in the process, lowering the amount of energy needed to enable a reaction.
Microscopic visualizations of these substances and materials in action can help to illuminate the fundamental building blocks for producing better industrial materials, electronics and pharmaceuticals.
Getting atomic-level looks at the surface of such substances and materials is one way to observe how “nanoparticles talk to the world,” and thereby “open a new window for exploration of atomic-level structural dynamics in materials,” says Crozier, a fellow of the Microscopy Society of America whose Crozier Research Group focuses in part on using electrons to see the atomic-level dynamics of materials.
Crozier and some of his colleagues recently published a paper in the research journal Science that describes combining artificial intelligence, or AI, technology with the capabilities of electron microscopy to reveal how these tiniest bits of matter — nanoparticles — respond to various stimuli.
Enhancing that response capability has the potential to open paths to progress for advances in numerous technical processes used in a broad range of industries.
Such an accomplishment requires overcoming a challenge presented by how speedily the atomic structures of nanoparticles are altered during chemical reactions, which means that understanding the functionality of the nanoparticles in a precise way demands gathering that data at high speed.
Demystifying processes occurring at nanoparticle level
Carlos Fernandez-Granda, an associate professor at New York University, or NYU, and one of the directors of its Center for Data Science, is one of Crozier’s co-authors on the research paper. He says it’s estimated that the production chain of 90% of all manufactured products involves catalytic processes and the possibility of developing an AI method to more deeply explore the atomic-level structural dynamics of catalytic materials could be transformative.
Another of the research paper’s authors, David S. Matteson, a professor and associate chair of Cornell University’s Department of Statistics and Data Science and director of the National Institute of Statistical Sciences, is quoted in an NYU news release detailing what recent research is revealing.
“This study introduces a new statistic that utilizes topological data analysis to both quantify fluxionality and to track the stability of particles as they transition between ordered and disordered states,” Matteson says.
With that kind of progress, Crozier says, “We are closer to having the ability to better understand processes at the nanoparticle level in ways that would open up paths to improving many technological and engineering endeavors.”
NYU’s report on the research also emphasizes the outlook for widespread societal impact emanating from progress on these ongoing collaborative research efforts.
The microscopic image at left of a nanoparticle of the widely used metal platinum shows an unprocessed particle, exhibiting little to no revealing detail about its atomic structure. The image on the right is from the exact same frame after an artificial intelligence process called denoising was applied to it, making the atoms (the small white blobs) visible. This gives researchers a clearer picture of the atomic and particle dynamics of the platinum’s surface.
Enhancing revelatory powers of microscopy
Recent research findings also point the way to overcoming complications because of the capability of electron microscopy to image structures with high spatial resolution and millisecond temporal resolution is often limited by what experts describe as poor signal-to-noise ratios, which obscure viewing millisecond movements at the atomic levels.
Using an AI-powered noise filter, called a deep denoising framework by researchers, Crozier’s team was able to enhance image clarity to see what was happening on metal nanoparticle surfaces more quickly than ever.
“We are now able to study the process to understand how it might impact technologies like catalysis,” he says.
In catalysis — which is essential for energy production, pollution control and chemical manufacturing — electron microscopy enables engineers to see exactly how catalysts behave under various conditions, potentially leading to the development of more efficient energy, chemical and information processes.
“We can see what atoms on a material’s surface are doing. At one point, they are in migration all over the place. Then a little later, the surface structure goes through a period of relative calm, when all the atoms are arranged in ordered, beautiful patterns,” Crozier says.
“Later this ordered structure dissolves and the atoms move chaotically again.,” he says. “This surface pattern or motif is constantly changing on the 1/100th of a second time frame.”
Showing the evolution of particle of platinum as its shape changes with time, the image captures a transition of matter taking place in a fraction of a second as the surface atoms of the material move constantly. Understanding the intricacies of such atomic-level movement provides scientist and engineers data to inform their research to learn how this process can be harnessed to develop technological innovations.
Potential for far-reaching technological progress
For electronics and computing, understanding how atoms move and reorganize under stress could help create more durable semiconductors and storage devices that maintain performance under extreme conditions.
These new ways to see more clearly and closely how materials behave at the atomic level could boost development of more effective medicines, more fast-acting computers and more robust high-performing fertilizers for agriculture.
ASU researchers have also been aiding efforts to combine capabilities in election microscopy and AI to see the structures and movements of molecules that are one-billionth of a meter in size at an unprecedented time resolution.
The recent work in advancing knowledge about the architecture of materials at the atomic level builds on earlier research involving nanoparticles by Crozier and some of his colleagues reported in “Dancing atoms reveal potential capabilities of materials.”
The latest progress is expected to help widen paths to developing newer advances in materials engineering that will result in a more promising array of beneficial practical applications.
Beyond that, Crozier says, such discoveries heighten the potential for groundbreaking achievements that could set the stage for expanding scientific knowledge to enable advanced capabilities in many branches of engineering.
