Stach Group
The Stach Group is a team of postdoctoral researchers, Ph.D. students, and undergraduates working across microscopy, materials chemistry, and device physics.
Robert D. Bent Professor of Engineering · Department of Materials Science & Engineering · University of Pennsylvania
Eric Stach is the Robert D. Bent Professor of Engineering in the Department of Materials Science and Engineering at the University of Pennsylvania, having joined in the Fall of 2017. He also serves as Director of the Laboratory for Research on the Structure of Matter (LRSM) and, since 2024, as Scientific Director of the Singh Center for Nanotechnology.
Before his appointment at Penn, he held several different positions, including Electron Microscopy Group Leader at the Center for Functional Nanomaterials, Brookhaven National Laboratory; Associate and then Full Professor at Purdue University; and Staff Scientist and Principal Investigator at the National Center for Electron Microscopy, Lawrence Berkeley National Laboratory.
His research interests focus on developing and applying electron microscopy techniques to solve a wide range of materials problems, with the most recent emphasis on catalysis, energy storage materials, solar photovoltaics, and nanostructure growth.
He is a Fellow of the American Physical Society, the Materials Research Society, and the Microscopy Society of America, and recently completed a term as President of of the Board of Directors of the Materials Research Society (in 2025). He has received several awards, including being named an ISI Highly Cited Researcher (Cross Field) in 2018, the Microscopy Society of America's Eli F. Burton (Young Scientist) Award, and Purdue University's Faculty Scholar, Early Career Research Excellence, and Reinhardt Schumann, Jr. Undergraduate Teaching Awards.
He is the author of over 300 peer-reviewed publications and has given over 250 invited lectures at conferences and university, government, and corporate laboratories. He is also a co-founder and was the Chief Technology Officer of Hummingbird Scientific for over 20 years, a nanotechnology company that enables advanced experimentation for electron and ion microscopes. He is a co-founder of Agni Semiconductor with Deep Jariwala and Troy Olsson.
Staff Scientist · PhD, IISc Bangalore (2021)
Dr. Rajeev received his Ph.D. in Materials Science from the Indian Institute of Science (IISc), Bangalore in 2021. During his Ph.D. he worked in the Nanomaterials & Microscopy group, designing synthesis protocols for 2D nanostructures with specific applications and characterizing them using transmission electron microscopy. He then held a brief postdoctoral appointment at the Functional Thin Films and Electron Microscopy Lab at CeNSE, IISc, investigating thin-film oxides by TEM. He joined the University of Pennsylvania as a Postdoctoral Research Associate in June 2022.
His research focuses on understanding the reaction mechanism for CO2 sequestration in minerals and other gas-phase catalytic reactions using in situ (S)TEM imaging and spectroscopy. He is also interested in phase transformation and atomic inter-diffusion using in situ (S)TEM methods. Beyond in situ techniques, he works with electron energy-loss spectroscopy (EELS) and 4D-STEM.
Postdoctoral Research Associate · PhD, Seoul National University (2024)
Jongbeom Kim earned his Ph.D. in Materials Science and Engineering from Seoul National University in 2024. He joined the University of Pennsylvania as a Postdoctoral Research Associate in November 2024.
He develops advanced electron and ion microscopy techniques to study soft materials under cryogenic conditions. As a trainee in Penn's MRSEC IRG2 — Bioinspired Engineering of Condensed Protein Mesophases and Cell Collectives — he studies the microscopic structural properties of liquid-crystal polymers and biomolecular condensates driven by liquid-liquid phase separation.
Cheng-Yu received a Bachelor's degree in 2019 and a Master's degree in 2021, both in Materials Science and Engineering from National Taiwan University. He joined the group at Penn in the Fall of 2022.
During his Master's studies, his research focused on reconstructing 3D microstructures by electron tomography using HAADF-STEM images. At Penn he is researching the degradation processes of supported nanocatalyst systems through in situ TEM imaging, combined with automated image analysis via machine learning.
Yinuo received a Bachelor's degree in 2021 from the Qingdao University of Science and Technology and a Master's degree in 2023 from the University of Pennsylvania. She joined the Stach group at Penn in the Summer of 2023 and is co-advised by Dr. Troy Olsson in the ESE department.
During her Master's studies, her research focused on improving the ferroelectric switching performance of AlScN thin films by manipulating deposition gas flow. At Penn she works on strategies to lower the coercive field and improve the endurance of AlScN memory devices, and on understanding the failure mechanism of thin-film memory devices through electron microscopy.
Erika joined the group in the Fall of 2022, after receiving her Bachelor's at Harvard University in the Spring of 2022.
Prior to Penn, Erika focused on optimizing the growth of transparent conductive oxides through molecular beam epitaxy and sputtering, or a combination of both techniques, guided by analysis using XRD and AFM. At Penn, her current focus is on exploring the surface attachment of molecular catalysts using STEM.
Swarnendu completed his Bachelor's in Metallurgical Engineering from Indian Institute of Technology (BHU) Varanasi, India in 2023. He joined the Stach group at Penn in the Fall of 2023.
Before joining Penn, Swarnendu focused on studying microstructural evolution and phase transformation in Inconel 625 produced by Laser Directed-Energy Deposition, analyzing XRD, SEM, and TEM data.
George received a Bachelor's degree in 2022 in Materials Science and Engineering from the University of Pennsylvania. Before joining the Stach group in the Fall of 2023, he worked as a Research Engineer for Nelumbo Inc.
During his Bachelor's degree, his research was in synthesis and STEM characterization of metallic core-shell nanoparticles for heterogeneous catalysis. His current focus is on high-pressure in situ TEM and machine learning for beam-sensitive materials as a Soft AE fellow.
Naishu is completing her Bachelor's in Artificial Intelligence at the University of Pennsylvania, and joined the Stach group at Penn in the Fall of 2025.
Naishu's work focuses on developing tools that improve access to and understanding of scientific literature. Her current work involves building a domain-specific literature chatbot that supports semantic search and grounded question-answering, with the goal of making technical research more accessible and easier to navigate.