PhD Candidate Wins Student Presentation Award at Fall MRS Meeting

From left to right: Ruku Borah, Shane Arlington, Megan Bokhoor, Michael Flickinger, and Tim Weihs.

From left to right: Ruku Borah, Shane Arlington, Megan Bokhoor, Michael Flickinger, and Tim Weihs.

Preetom (Ruku) Borah, a PhD candidate in the Department of Materials Science and Engineeringearned a Student Presentation Award for his lecture in the Advances in Reactive Materials Engineering Symposium at the 2023 Materials Research Society (MRS) Fall Meeting & Exhibit, held in Boston, Massachusetts in late November. 

Borah works in the lab of Tim Weihs, a professor of materials science and engineering and director of the Materials Science in Extreme Environments University Research Alliance (MSEE URA), where he focuses on approaches to counteracting chemical warfare agents (CWAs). 

Borah’s winning presentation described key findings from experiments with diisopropyl methyl phosphonate (DIMP), a gas simulant. In one study, he ignited a combination of metallic powders to diffuse the effects of DIMP. He found that by controlling the combustion of these powders in the presence of DIMP vapor, the simulant showed signs of decomposition, suggesting neutralization of the gas. The signs of neutralization point toward the possibility of alternate ways to diffuse chemical agents, he said. 

Next, Borah plans to identify ways to control the decomposition of DIMP using various mixtures of aluminum, magnesium, and zirconium.  

“The goal going forward is to see, now that we’ve demonstrated the capability to neutralize DIMP with one chemistry, how can we tune that decomposition?” says Borah. “The next step is to test multiple chemistries, seeing what’s going to improve or detract from that decomposition.”

Faculty team receives U.S. DoE award for SciML research under CAIMEE

An interdisciplinary team of Whiting School faculty members has been chosen to receive a U.S. Department of Energy Award.

This four-year, $4.8 million grant from the Department of Energy’s Office of Science promotes research on scientific machine learning focused on greater predictive capabilities for scientific simulations. The award will be managed by the Hopkins Extreme Materials Institute as part of its Center on Artificial Intelligence for Materials in Extreme Environments (CAIMEE).

The team is led by Michael Shields and includes Dimitris Giovanis, Somdatta Goswami (soon joining WSE as a faculty member), Lori Graham-Brady, Yannis Kevrekidis, and Tamer Zaki.

Shields, Giovanis, Graham-Brady, Kevrekidis, and Zaki are HEMI fellows, and Graham-Brady is the director of CAIMEE.

Their project, “Physics and Uncertainty Informed Latent Operator Learning,” seeks to address two of the primary challenges to widespread adoption of scientific machine learning (SciML) methods and their applications in the physical, natural, and engineering sciences: scaling of SciML methods to large-scale problems with highly complex physics and the simultaneous quantification of uncertainty.

It aims to develop novel physics-informed neural operators that exploit the underlying low-dimensional structure of high-dimensional physics-based models which will focus on applications in fracture mechanics of additively manufactured composites and high-speed fluid flow.

Rethinking the building blocks of soil mechanics

Understanding how granular materials and rocks react under stress is crucial to projects ranging from building stable roads and bridges to formulating pills and cosmetics. Soil and rock mechanics are also integral to academic fields such as civil engineering, materials science, geology, and seismology.

When granular materials experience stress, they can start to behave in a fluid-like manner. This behavior is known as plastic flow, and plasticity theories attempt to explain this and related phenomena. Although plasticity theories have been developed and used for decades, there have been no direct stress or strain measurements to validate them, in part because of the significant challenges in directly measuring stress deep within a deforming material.

Using advanced imaging techniques and a unique experimental approach, researchers at the Hopkins Extreme Materials Institute have collected data that is among the first of its kind. Ryan Hurley, assistant professor of mechanical engineering in the Whiting School of Engineering, leads a research group studying the mechanical behavior and failure mechanisms of various geomaterials. Hurley and his collaborators (including mechanical engineering doctoral students Brett Kuwik and Kwangmin Lee and former HEMI postdoctoral fellow Ghassan Shahin) have recently had their findings published in Proceedings of the National Academy of Sciences.

During this study, the team performed triaxial compression tests on synthetic quartz sands, with x-ray imaging and diffraction offering some of the first known in-situ grain stress and local strain measurements.

Using a specialized triaxial compression instrument developed in Hurley’s lab, the researchers placed quartz sand samples under confining pressures between 20 and 35 MPa—2900 to 5000 pounds per square inch (PSI)—and analyzed them using synchrotron x-ray tomography and 3D x-ray diffraction at the Advanced Photon Source at Argonne National Laboratory.

“Results from this study provide the first direct confirmation of some of the fundamental postulates we use when studying the plastic deformation of sands,” said Hurley. “On the other hand, our results contradict prior assumptions such as the existence of ‘dead zones’ outside of regions of localized straining, indicating that some fundamental ideas about plastic flow in granular materials may need to be revisited.”

The team says these findings provide an opportunity for scientists to begin evaluating certain assumptions about how granular materials such as sand respond to stress, re-evaluate old ideas, and validate and expand upon existing models in soil and rock mechanics.


3D x-ray images of sand before and after axial straining, along with renderings of the sample. Sand particles are colored by their motion (instantaneous rotations) and stress. See Hurley’s paper in this edition of PNAS for additional details.

Rebecca Schulman named 2023 Vannevar Bush Faculty Fellow

headshot of Rebecca Schulman

Rebecca Schulman, an associate professor in the Department of Chemical and Biomolecular Engineering, has been named one of 10 2023 Vannevar Bush Faculty Fellows by the U.S. Department of Defense. The five-year, $3 million individual award aims to facilitate the progression of fundamental research, encourage collaboration between researchers and national defense experts, and enable investigators to pursue breakthrough discoveries in their fields.

Schulman, who holds secondary appointments in chemistry and computer science, is a HEMI fellow exploring the interfaces of materials science, biochemistry, circuit design, soft matter physics, and cell-free synthetic biology. Her project, “Self-organizing Biomaterials Using Biomolecular Networks,” will investigate how engineers can build complex machines and materials by applying similar principles to those used in biological development.

“Genes build living things by hierarchically organizing molecules, organelles, cells, tissues, and organs,” said Schulman. “Our project will investigate whether engineers might adopt similar ideas.”

Schulman is looking forward to her fellowship term and expressed gratitude for the people who have assisted her in her efforts so far. Preliminary data and concepts for this fellowship were obtained through an AI for materials seed project funded through the Center for Materials in Extreme Dynamic Environments.

“I am excited about the opportunity to deeply explore new ideas and take risks,” said Schulman.

News flash: Study decodes secrets of impacts in space

Impacts by debris and meteoroids pose a significant threat to satellites, space probes, and hypersonic craft. Such high-velocity impacts create a brief, intense burst of light, known as an impact flash. These flashes contain information about both the target and the object that caused the impact. For example, scientists have studied the impact of meteoroids on the moon by monitoring and analyzing impact flashes on its dark side.

A team of Johns Hopkins Whiting School of Engineering researchers led by mechanical engineering doctoral student Gary Simpson, Professor of Science and Engineering K.T. Ramesh, and colleagues have discovered that impact flashes are created by the fragmentation of an ultra-fast jet of material ejected from the colliding bodies. Their results appear in PNAS Nexus.

Working in the Hopkins Extreme Materials Institute’s HyFIRE lab, the team shot stainless steel spheres into an aluminum alloy plate at a speed of three kilometers per second—about 6,700 miles per hour, or more than nine times the speed of sound. The resulting impact flashes were photographed using ultra-high-speed cameras and high-speed spectroscopy, which measures the color and brightness of the light.

Immediately after impact, a luminous disc is seen expanding around the impacting sphere. Only a few millionths of a second later, the disc takes on an almost floral shape, as fragments ejected from the impact crater form an ejecta cone, with petal-like projections at the outer edge.

“We found that minuscule, condensed fragments from the jet interact with the atmosphere to create an extremely bright radiating cloud of vapor, which expands at a speed of over ten kilometers per second, or more than 22,000 miles per hour,” said Simpson. “The material making up the target and the size of the jetted particles can be inferred from the flash.”

Other authors of the study include Justin Moreno, HEMI associate staff engineer, and Matthew Shaeffer, HEMI senior staff engineer. Both are faculty members in applied biomedical engineering at the Whiting School’s Engineering for Professionals program.

HEMI fellow Paulette Clancy to be appointed Edward J. Schaefer Professor in Engineering

Paulette Clancy will be appointed the Edward J. Schaefer Professor in Engineering as of July 1.

Clancy, who serves as department head and professor in the Department of Chemical and Biomolecular Engineering, is a HEMI fellow specializing in computational materials processing. Her research group studies advanced organic materials, algorithm development, machine learning, and renewable energy materials. Clancy is also the director of research (discovery and inquiry) for Johns Hopkins AI-X Foundry and associate director of the Johns Hopkins Center for Integrated Structure-Mechanical Modeling and Simulation (CISMMS).

The Edward J. Schaefer Professorship in Engineering was endowed by Edward J. Schaefer ’23 and his wife, Hildegarde Schaefer. He was instrumental in opening a discrete school of engineering at the university.

Thomas Gernay receives National Science Foundation’s Early CAREER Award

Thomas Gernay, assistant professor in the Department of Civil and Systems Engineering, has been honored with the National Science Foundation’s Early CAREER Award.

This award recognizes early-career researchers who have demonstrated a significant level of promise and excellence.

Thomas is the founder and leader of the Multi-Hazard Resilient Structures research group at Johns Hopkins. Thomas has been developing innovative means to advance the resilience of the built environment against fire. His pioneering project, titled “Performance-Based Fire Design for Cold-Formed Steel Structures,” has received a five-year grant that will enable more precise modeling of the effects of fire on cold-formed steel structures.

This project will revolutionize our understanding of the field of fire design and materials science.


HEMI launches the Center on Artificial Intelligence for Materials in Extreme Environments

The Johns Hopkins University announces the establishment of the Center on Artificial Intelligence for Materials in Extreme Environments (CAIMEE), a new center within the Hopkins Extreme Materials Institute dedicated to the development of new materials and structures for use in extreme environments through the use of artificial intelligence and machine learning.

Materials in extreme environments present numerous research challenges that CAIMEE aims to solve by leveraging robotics, novel experimentation, accelerated computational models, and data-driven design iterations. Directed by Lori Graham-Brady, associate director of HEMI and professor in the Department of Civil and Systems Engineering, CAIMEE brings together 12 PIs and collaborators from several institutions to overcome these barriers. Jaafar El-Awady, a professor in the Department of Mechanical Engineering, will serve as CAIMEE’s co-director.

The center has a mission of enabling the development of materials with properties tailored for sustainable performance in extreme environments like those encountered by the Department of Defense, the Department of Energy, and the National Aeronautics and Space Administration. According to the announcement from Dean Ed Schlesinger, the new tools and technologies to be employed by CAIMEE researchers will revolutionize the way materials design decisions are made and will provide comprehensive data and information for sustainable materials development in extreme environments.

This new center is a significant development in the field of research and will have a direct impact on the development of essential materials for critical applications. It is expected that CAIMEE’s work will significantly contribute to the growth of innovations and discoveries that will help governments and industries tackle critical problems.

Sabine Stanley named next vice provost for graduate and professional education

HEMI Fellow Sabine Stanley, a planetary physicist whose research aims to answer fundamental questions about the nature and interior structure of planets in our solar system and beyond, has been named vice provost of graduate and professional education at Johns Hopkins University.

“We are fortunate to be able to call on someone with Sabine’s leadership and administrative experience to build on the great foundation that Nancy has created,” said Provost Sunil Kumar.

Sabine is passionate about graduate and postdoctoral training and has extensive experience in teaching and mentoring students.

Stanley joined the university in 2017 as a Bloomberg Distinguished Professor in the Department of Earth & Planetary Sciences at JHU’s Krieger School of Arts and Sciences and in the Space Exploration Sector of the Applied Physics Lab. She is a renowned physicist whose work focuses on planetary magnetic fields, dynamo theory, and planetary interiors and evolution.

Stanley received a BSc degree in physics and astronomy from the University of Toronto and MA and PhD degrees in geophysics from Harvard. She will assume her provost’s office role beginning May 1.

“I’m excited to take on this role and work with the provost’s office and all the schools to support our graduate student and postdoctoral training missions,” said Stanley.

Portions of this article was excerpted from The Hub. You can view the full story here.