Previous APMS Colloquia
Fall 2021
Thursday, December 9, 4:00-5:00 pm
Jaime Diaz (NAU)
Simulating Energy Transfer In Photosynthesis Using Quantum Computations
Jorge Muñoz (NAU)
The impact of nanostructure on chiro-optical materials: Atomic Force Microscopy of TiO2+Au Nanohelices
Jake Navas (NAU)
Quantum Tomography
Thursday, December 2, 4:00-5:00 pm
Joel Johnson (NAU)
Optomechanical Cooling in Liquid-core Optical Fiber
Blake Rogers (NAU)
Optimizing Gold Seeds for Nanorod Synthesis
Thursday, November 4, 4:00-5:00 pm
Prof. Claire E. White (Princeton Univ.)
- Associate Professor of Civil and Environmental Engineering and the Andlinger Center for Energy and the Environment
The materials science of sustainable cements
Abstract: With the world facing a climate crisis due to increasing CO2 emissions, there is pressing need to develop and implement sustainable construction/engineering materials across the globe. Alkali-activated materials (AAMs) are one such sustainable alternative to conventional Portland cement concrete; yet questions remain regarding the long-term behavior of AAMs. Furthermore, for Portland cement, the use of extensive clinker substitution to reduce CO2 emissions has led to changes to the underlying chemistry of the main binder gel (calcium-silicate-hydrate, C-S-H, gel), where it is uncertain how these novel supplementary cementitious materials augment the long-term behavior (e.g., gel stability and pore structure) of the cement binder. In this talk, I will outline how fundamental materials science research is being used to address the long-term behavior unknowns of AAMs and certain Portland cement-based systems, where we are linking key experimental techniques with atomistic and larger length scale simulations. In particular, to assess gel stability in calcium-rich AAMs, we have used density functional theory (DFT), synchrotron-based X-ray pair distribution function (PDF) analysis and nuclear magnetic resonance (NMR) to investigate the influence of alkali and alumina incorporation on the structure and thermodynamics of C-S-H gel. The DFT results point toward a clear upper limit for sodium incorporation, beyond which the stability of the phase is compromised, while the experimental results show how alumina can be utilized to combat the destabilizing effects of sodium. We have also used DFT to uncover the early stage formation behavior of C-S-H gel and the influence of sodium and alumina, which has led to a tentatively proposed formation mechanism of the gel.
Bio: Claire White is an associate professor in the Department of Civil and Environmental Engineering and the Andlinger Center for Energy and the Environment, and is the acting associate director for research in the Andlinger Center for Energy and the Environment. She holds associated faculty status in the Departments of Chemical and Biological Engineering, and Mechanical and Aerospace Engineering, the Princeton Institute for the Science and Technology of Materials, High Meadows Environmental Institute, and Princeton Institute for Computational Science and Engineering. She completed her graduate studies in 2010 at the University of Melbourne supported by an Australian Postgraduate Award from the Australian government. After receiving her PhD, she worked as a postdoc at Los Alamos National Laboratory and was awarded a Director’s Postdoctoral Fellowship to research the atomic structure of low-CO2 alkali-activated materials. In 2013 she joined Princeton University.
White’s research focuses on understanding and optimizing engineering and environmental materials, including sustainable cements and materials for carbon capture, utilization and storage. One main thrust of her research portfolio entails the discovery and control of the chemical mechanisms responsible for formation and long-term degradation of low-CO2 cements and related systems. A second thrust is the development of new 2D materials for carbon capture with significantly reduced energy requirements for material regeneration. This research spans multiple length and time scales, utilizing advanced synchrotron and neutron-based experimental techniques, and includes the use and development of atomic and mesoscale simulation methodologies. Professor White is the recipient of a number of awards including an NSF CAREER Award, the RILEM Gustavo Colonnetti Medal, and the Howard B. Wentz Jr. Junior Faculty Award (Princeton University), and has been listed numerous times on the Princeton Engineering Commendation List for Outstanding Teaching.
Thursday, October 28, 4:00-5:00 pm
Prof. Douglas Shepherd (Arizona State Univ.)
- Assistant Professor, Department of Physics
Scalable, high-speed, 3D imaging of molecular biology in action
Abstract: Continued advancements in biomedical optical microscopy and fluorescent labeling techniques have enabled multi-dimensional visualization of biology in action at the single-molecule level. For example, multiple large-scale efforts are currently underway to create nanoscale spatial maps of thousands of individual RNA and protein species in millions of cells across all human organs. Many of the experiments across these efforts rely on multiplexed fluorescence molecular imaging. The quality and confidence of biological knowledge extracted from the resulting digital images depend on the molecular labeling strategy, the optical microscope’s design, and detector choices. Compromises are often necessary to achieve the required volume, imaging speed, number of molecules, samples, or other biologically driven experimental design criteria. Such compromises inevitably increase uncertainty when quantifying molecular identity and dynamics. I will discuss our recent efforts to reduce uncertainty in quantitative molecular imaging through improvements to the optical methods and computational tools used for high-speed, high-resolution, multiplexed, and volumetric fluorescence molecular imaging. Our efforts include a high numerical aperture oblique plane microscopy framework for 3D spatial transcriptomics in human tissue and a digital micromirror-based structured illumination microscopy framework for live-cell, sub-diffraction limited imaging.
Bio: Douglas Shepherd is an assistant professor in the Center for Biological Physics and the Department of Physics at Arizona State University. Prior to joining Arizona State University, he was an assistant professor in the Departments of Physics and Pharmacology at the University of Colorado Denver Anschutz Medical Campus from 2013-2019. He received his Ph.D. in Physics from Colorado State University and was a postdoctoral fellow at the Center for Integrated Nanotechnologies and Center for Nonlinear Studies at Los Alamos National Laboratory from 2011-2013. The focus of his research is developing quantitative imaging and statistical inference tools to build predictive models of genetic regulation in multi-cellular systems.
Thursday, October 21, 4:00-5:00 pm
Prof. Edward J. Maginn (Univ. of Notre Dame)
- Professor, Department of Chemical and Biomolecular Engineering
Understanding the Thermophysical Properties of Charged Fluids Using Molecular Simulations: A Journey from Molten Salts, to Ionic Liquids, and Back Again
Abstract: High temperature molten salts were some of the first liquids to be studied in the 1960s and 1970s using the newly invented methods of molecular dynamics and Monte Carlo simulations. Simple salts such as 1:1 alkali halides were particularly attractive systems to model, given computational and algorithmic limitations of the time and the availability of experimental data against which computed properties are compared. Furthermore, there was a great deal of interest in understanding how charged fluids could be modeled computationally and whether both thermodynamic and transport properties could be captured using potentials that consisted of separate terms to treat long-range Coulombic interactions and shorter-ranged repulsion and dispersion interactions. Despite their importance in applications such as metal processing, heat transfer, and nuclear power, molten salt research fell out of favor, only to be replaced at the turn of the 21st century by low temperature “ionic liquids” – a new type of molten salt that was liquid at room temperature. Ionic liquids share many of the same properties as their high temperature cousins, but they also can have both polar and non-polar domains, giving them some unique solvation properties. Due to their low melting temperature, it is also much easier to study ionic liquids than molten salts.
In this talk, I will demonstrate how molecular simulations can help us understand how the thermophysical properties of high temperature molten salts and low temperature ionic liquids depend upon things such as structure, charge density, and composition. Motivated by applications such as battery electrolytes, solvents for gas separations, and safer nuclear energy generation, I will show how molecular simulations, machine learning, and advanced experimental characterization methods are helping us better understand these fascinating charged fluids.
Thursday, October 14, 4:00-5:00 pm
Prof. Brian Munsky (Colorado State Univ.)
- Associate Professor, Chemical & Biological Engineering
Designing Optimal Microscopy Experiments to Harvest Single-Cell Fluctuation Information while Rejecting Image Distortion Effects
Abstract: Modern fluorescence labeling and optical microscopy approaches have made it possible to experimentally observe every stage of basic gene regulatory processes, even at the level of individual DNA, RNA, and protein molecules, in living cells, and within fluctuating environments. To complement these observations, the mechanisms and parameters of discrete stochastic models can be rigorously inferred to reproduce and quantitatively predict every step of the central dogma of molecular biology. As single-cell experiments and stochastic models become increasingly more complex and more powerful, the number of possibilities for their integrated application increases combinatorically, requiring efficient approaches for optimized experiment design. In this presentation, we will introduce two model-driven experimental design approaches: one based on detailed mechanistic simulations of optical experiments, and the other on a new formulation of Fisher Information for discrete stochastic process models. Using combinations of real biological experiments and realistic simulated data for single-gene transcription and single-RNA translation, we will demonstrate how experiment design approaches can be reformulated to account for non-gaussian noise within individual cells as well as for non-trivial measurement noise effects due to optical distortions and image processing errors.
Bio: Dr. Munsky received B.S. and M.S. degrees in Aerospace Engineering from the Pennsylvania State University in 2000 and 2002, respectively, and his Ph.D. in Mechanical Engineering from the University of California at Santa Barbara in 2008. Following his graduate studies, Dr. Munsky worked at the Los Alamos National Laboratory — as a Director’s Postdoctoral Fellow (2008-2010), as a Richard P. Feynman Distinguished Postdoctoral Fellow in Theory and Computing (2010-2013), and as a Staff Scientist (2013). He joined the Department of Chemical and Biological Engineering and the School of Biomedical Engineering as an Assistant Professor in January of 2014 and was promoted to Associate professor in 2020. Dr. Munsky is best known for his discovery of Finite State Projection algorithm, which has enabled the efficient study of probability distribution dynamics for stochastic gene regulatory networks. Dr. Munsky’s research interests at CSU are in the integration of stochastic models with single-cell experiments to identify predictive models of gene regulatory systems and more complex biological systems, and his research is actively funded by the W M Keck Foundation, the NIGMS (MIRA), and the NSF (CAREER). Dr. Munsky is excited about the future the introduction of tools from physics and engineering into the quantitative study and modeling of biological processes, and he would love to talk about this with you!
Thursday, October 7, 4:00-5:00 pm
Prof. Manuel Quevedo
(Univ. of Texas at Dallas)
- Professor and Department Head, Dept. of Materials Science and Engineering
Large Area Solid-State Radiation Detectors
Abstract: The development of low temperature device technologies that have enabled flexible displays also present opportunities for flexible electronics and flexible integrated systems. In this presentation, we discuss fundamental materials properties including crystalline structure, interfacial reactions, doping, etc., defining performance and reliability of perovskite II-VI and oxide-based materials and devices for flexible and large area electronics. Materials characterization methods including RBS, XPS, XRD, etc. are used to analyze materials deposited by pulsed laser deposition, chemical bath deposition and inkjet printing. Finally, we demonstrate an integrated neutron / gamma ray sensor fully fabricated at UT-Dallas that includes wireless communication to a mobile device.
Thursday, September 30, 4:00-5:00 pm
Prof. Mariana Potcoava
(Univ. of Illinois at Chicago)
Use of optical instrumentation for quantitative analysis of cellular biological processes
Abstract: My research is directed to the development of optical instrumentation for biomedical measurements and addresses two broad topics: 1) Holography in tomographic imaging, and 2) Application of Raman spectroscopy in the life sciences.
Here, I will discuss our recent advances in building an incoherent detection arm for a Lattice Light-Sheet (LLS) microscope, called Incoherent Holography Lattice Light-Sheet (IHLLS). I will discuss development of this system including characterization of its performance and demonstrate a significant contrast improvement using both beads and neuronal structures within a biological test sample as well as quantitative phase imaging. The IHLLS has similar or better transverse and performance when compared to the LLS technique. In addition, the IHLLS allows for volume reconstruction from fewer z-galvo displacements, thus facilitating faster volume acquisition.
I have also worked on a technology that demonstrates the potential of Raman spectroscopy to determine with high accuracy the composition changes of the fatty acids and cholesterol found in the lipid droplets of prostate cancer cells treated with various fatty acids. The methodology uses a modified least-square fitting (LSF) routine that uses highly discriminatory wavenumbers between the fatty acids present in the sample using a new Support Vector Machine (SVM) algorithm.
Thursday, September 16, 4:00-5:00 pm
Dr. Helen Maynard-Casely (Australian Nuclear Science and Technology Organisation)
Cryomineralogy, like mineralogy only cooler
Abstract: Ocean worlds have solid surfaces, and although water ice dominates many of these surfaces it material properties will be heavily influenced by the other chemical species it crystallises with. Moreover, studies of the minerals that form on these surfaces are clues as to what may lie below. Though we cannot yet reach these icy satellites and return a sample to Earth for investigation, we can recreate their simple compositions and extreme conditions in the laboratory. In contrast to terrestrial mineralogy, which has been subject to 100 years of laboratory measurements, we are only beginning to shed light on the range of materials that are formed on the ocean worlds.
Through laboratory studies cryominerals have been shown to be just as diverse as silicates in the structures and physical properties that they exhibit [1]. From influence of sulfate on governing what water-rich hydrates form on Europa [2], to the plastic solids of methane and nitrogen that form on Pluto [3]. A new and particularly rich area of discovery recently has been the variety of minerals that are likely to be formed on Saturn’s moon Titan [4] [5]. This contribution will highlight recent developments in cryomineralogy, but also point to where much more laboratory work, and complementary modelling is needed.
1. Fortes, A.D. and M. Choukroun, Phase Behavior of Ices and Hydrates. Space Science Reviews, 2010. 153(1-4): p. 185-218.
2. Maynard-Casely, H.E., et al., Mineral Diversity on Europa: Exploration of Phases Formed in the MgSO4–H2SO4–H2O Ternary. ACS Earth and Space Chemistry, 2021.
3. Maynard-Casely, H.E., J.R. Hester, and H.E.A. Brand, Re-examining the crystal structure behavior of nitrogen and methane (in press). IUCrJ, 2020.
4. Maynard-Casely, H.E., et al., Prospects for mineralogy on Titan. American Mineralogist, 2018. 103(3): p. 343-349.
5. Cable, M.L., et al., Titan in a Test Tube: Organic Co-crystals and Implications for Titan Mineralogy. Accounts of Chemical Research, 2021: p. 4087-4094.
Thursday, September 16, 4:00-5:00 pm
Prof. Andrew White (Univ. of Rochester)
Iterative Peptide Discovery with Maximum Entropy Methods and Deep Learning
Abstract: The use of artificial intelligence for molecular design has been rapidly advancing. New generative models propose novel molecular structures to test, and deep learning can predict their molecular properties with high accuracy. The goal for these algorithms is optimizing a property by training against a large database of previously measured molecules. A major limitation is that these methods are not designed to be used concurrently with experiments and improving their accuracy as experimental data is gathered is non-trivial. Our research is focused on iterative molecular design where experiments are done concurrently instead of post-hoc in molecular design. This is accomplished by using maximum entropy biasing methods that can update predictive physics-based models with new experimental results.1 This improves predictive accuracy and ensures interpretable models.</p
Another challenge is the scarcity of data in molecular design. We are exploring with this with advances from few-shot learning, like meta-learning.2 Meta-learning translates experience from past related systems to new ones, minimizing the number of molecules necessary to train models. I will present results of these methods applied to peptides where we have studied a variety of tasks including antimicrobial, antifouling, and solubility predictions. Peptides are a model system because there is no ambiguity in encoding and generating them because they are linear biopolymers made of 20 amino acid monomers.
1. Experimentally Consistent Simulation of Aβ21–30 Peptides with a Minimal NMR Bias. DB Amirkulova, M Chakraborty, AD White – The Journal of Physical Chemistry B, 2020
2. Investigating Active Learning and Meta-Learning for Iterative Peptide Design. R Barrett, AD White – Journal of chemical information and modeling, 2021
3. Sequence, structure, and function of peptide self-assembled monolayers.
AK Nowinski, F Sun, AD White, AJ Keefe, S Jiang – Journal of the American Chemical Society, 2012.
Thursday, September 9, 4:00-5:00 pm
Prof. Martin L. Kirk (Univ. of New Mexico)
- Distinguished Professor of Chemistry
Donor-Acceptor Systems Provide Insight into Charge Separation, Charge Transport, and Excited State Processes
Abstract: Excited state interactions in spin-containing Donor-Acceptor and Donor-Bridge-Acceptor systems are important for understanding the impact of electronic coupling (Hab) on molecular electronics and how magnetic exchange interactions affect excited state processes. Our efforts have focused on determining excited state contributions to molecular bridge mediated electronic coupling, understanding how open-shell excited state singlet configurations promote long-range electron correlation, correlating magnetic exchange with molecular conductance, and developing new platforms for spin control of excited state dynamics in photoexcited donor-acceptor molecules. Using novel Donor-Bridge-Acceptor biradical and related complexes, we have been able to test recent theoretical hypotheses in molecular electronics as they relate to coherent superexchange in electron transfer/transport conduits, spin-polarized electron transport, and the control of quantum interference effects. Radical elaborated transition metal complexes represent ideal platforms for exploring the relationship between photoinduced charge separation and long-range spin correlation, impacting the solar energy, organic lighting, and molecular spintronics fields. These systems are also relevant to the emerging molecular quantum information science (QIS) field, allowing for the optical generation and manipulation of spin qubits. Here we will show how a combined spectroscopic and magentic approach, augmented by detailed bonding calculations, has provided keen insight into the electronic structure of these novel radical containing complexes in order to further our understanding of molecular electronic systems at the nanoscale.
Spring 2021
Thursday, April 15, 4:00-5:00 pm, on Zoom
Prof. Bertrand Cambou (NAU)
- Professor, Nanotechnology and Cybersecurity
- Invention Ambassador of the American Association for the Advancement of Science
The nanoscale CMOS: from microelectronics to nanoelectronics
Abstract: One of the driving forces of the microelectronic industry has been its ability to successfully shrink the size of the active components from the micrometer level to the 5 nm level. This has allowed to double the density of components per mm2 every two years and increase performance.
Going forward it seems that this breathtaking pace will continue for another 15 to 20 years, however the investments needed are so commensurable that only three corporations worldwide were able to stay in the game. It is interesting to notice that two out of these three leaders are now massively investing in Arizona, making our state “the” hot spot worldwide.
This talk is a device physicist’s view of this journey, focusing on the CMOS (complementary metal-oxide-semiconductor), the most important component for microelectronics. Eventually the size of the active components will come too close to the size of elementary atoms, the laws of quantum physics will be predominant, opening up the era of quantum computing.
Bio: Dr. Bertrand Cambou is a Professor at Northern Arizona University (NAU) in nanoelectronics and cybersecurity. He is the Principal Investigator (PI) of a $6,000,000 program funded by the Air Force Research Laboratory (AFRL) to use nanotechnologies for cybersecurity, and quantum cryptography. With 100 granted and pending patents, he is an Invention Ambassador of the American Association for the Advancement of Science (AAAS), and a senior member of the National Academy of Inventors (NAI). He worked as a senior executive and a technologist in the cybersecurity industry at Gemplus and Ingenico, and in microelectronics at Advanced Micro Devices (AMD), Motorola, Silicon Storage Technology (SST), and Crocus Technology. At Motorola he was a distinguished innovator, and a scientific advisor of the corporation’s Board of Directors. He was nominated by IBM and Motorola as the Director of the Somerset Power PC microprocessor design center, in support of Apple Computer. He holds a Doctorate degree in Electronics and Material Science from Paris-Saclay University, an Electrical Engineering degree from Supelec-Paris, and a Master degree in Physics from Toulouse-III University.
Thursday, April 8, 4:00-5:00 pm, on Zoom
Prof. Stephen M. Goodnick (Arizona State Univ.)
- Professor
Ultra Materials for a Resilient, Smart Electricity Grid
Abstract: A resilient, smart electricity grid is necessary to integrate multiple energy sources, power storage capabilities, and diverse electrical needs, and ultra-wide bandgap (UWBG) semiconductors have been identified as a crucial enabling materials technology. The UWBG semiconductor and dielectric materials (or ‘ultra’ materials) present a new realm for high field transport, electron-phonon interactions, and heat transport. Understanding their novel properties will enable new classes of high power devices and components which can provide efficient energy conversion and control (Smart Grid) with a significant reduction in system size supporting a resilient energy grid.
The ultra semiconductors include cubic diamond, hexagonal AlN and the BxAl1-xN alloy system which bridges the crystal structures. These materials are all characterized by wide bandgaps (>5 eV) leading to much higher breakdown fields compared to present power electronic materials. They have also demonstrated high carrier mobilities and velocities allowing for high current with low on-resistance. Also, ultra materials like diamond have very high thermal conductivities which is advantageous for high power applications.
However, there are a number of challenges to the development of commercial technologies based on these relatively new material systems. These include the growth of high quality single crystal materials with controllable defects, and the ability to dope materials both n- and p-type, which is a particular challenge in wide bandgap materials. The growth of high quality heterointerfaces between different ultra materials is necessary for realizing various device technologies such as heterojunction field effect transistors. Understanding the dynamics of carrier transport under extremely high electric fields is critical to understanding the limiting mechanisms to breakdown, and harnessing new phenomena such as direct field emission into vacuum from materials where the conduction bands are close to or above the vacuum level itself. Finally, understanding thermal energy transport is critical if the development of efficient high power components, where heat management is essential. To address these challenges, the Department of Energy has awarded Arizona State University an Energy Frontier Research Center (EFRC) dedicated to the development of ultra materials for high power applications.
In this talk, we will focus on on-going research within the Ultra EFRC, where the mission is to understand fundamental phenomena in UWBG materials – including synthesis, defect and impurity incorporation, electronic structure at interfaces, interaction of electrons and atomic vibrations at high fields, to achieve extreme electrical properties, and efficient thermal transport. The Ultra EFRC is also establishing a Future Grid Co-Design Ecosystem, which will bring together international experts to assess the impact of new ultra materials on potential applications in power electronics and the future energy grid, and guide the direction of center.
Bio:Prof. Goodnick is currently the David and Darleen Ferry Professor of Electrical Engineering at Arizona State University. He received his Ph.D. degrees in electrical engineering from Colorado State University, Fort Collins, and was an Alexander von Humboldt Fellow in physics with the Technical University of Munich, Germany, and the University of Modena, Italy, from 1985 to 1986. He served as Chair and Professor of Electrical Engineering with Arizona State University, Tempe, from 1996 to 2005. He served as Associate Vice President for Research for Arizona State University from 2006-2008, and presently serves as Deputy Director of ASU Lightworks. He recently was a Hans Fischer Senior Fellow with the Institute for Advanced Studies at the Technical University of Munich (2013-2018). Professionally, he served as President (2012-2013) of the IEEE Nanotechnology Council, and served as President of IEEE Eta Kappa Nu Electrical and Computer Engineering Honor Society Board of Governors, 2011-2012. Some of his main research contributions include analysis of surface roughness at the Si/SiO2 interface, Monte Carlo simulation of ultrafast carrier relaxation in quantum confined systems, global modeling of high frequency and energy conversion devices, full-band simulation of semiconductor devices, transport in nanostructures, and fabrication and characterization of nanoscale semiconductor devices. He is a Fellow of IEEE for contributions to carrier transport fundamentals and semiconductor devices.
Thursday, April 1, 4:00-5:00 pm, on Zoom
Prof. Mariana Bertoni (Arizona State Univ.)
- Fulton Energy and Materials Professor
- School of Electrical, Computer and Energy Engineering
Multimodal X-ray Microscopy: The Kinetics of Cu in CdTe Absorbers
Abstract: The behavior of solar cells is very often limited by inhomogeneously distributed nanoscale defects. This is the case throughout the entire lifecycle of the solar cell, from the distribution of elements and defects during solar cell growth as well as the charge-collection and recombination during operation, to degradation and failure mechanisms due to impurity diffusion, crack formation, and irradiation- and heat-induced cell damage. This has been known for a while in the field of crystalline silicon, but inhomogeneities are far more abundant in polycrystalline materials, and are the limiting factor in thin-film solar cells where grain sizes are often on the order of the diffusion length.
We will show that the high penetration of hard X-rays combined with the high sensitivity to elemental distribution, structure, and spatial resolution offers a unique avenue for highly correlative studies at the nanoscale. We will present results on Cu-doped CdTe, where carrier collection is directly correlated to the kinetics of Cu inside the absorber and the particular Cu- phases at the ZnTe/CdTe interface. We will complement the results with modeling using PVRD- FASP and PyCDTS.
Bio: Mariana Bertoni is the Fulton Energy and Materials Professor in the School of Electrical, Computer and Energy Engineering at Arizona State University. She joined ASU’s faculty after holding senior scientist positions at two startup companies in the photovoltaic industry and a postdoctoral fellowship at the Massachusetts Institute of Technology. Professor Bertoni received her Ph.D. from Northwestern University in Materials Science and Engineering and her Diploma in Chemical Engineering from the Instituto Tecnologico de Buenos Aires. She is a former Fulbright Scholar and a Marie Curie Fellow. In 2016, she was named Outstanding Assistant Professor in the Fulton Schools of Engineering and in 2017 was invited to the National Academy of Engineering U.S. Frontiers of Engineering as one of the nation’s outstanding young engineers. In 2018, she won the NAE’s Grainger Foundation Frontiers of Engineering Award for Advancement of Interdisciplinary Research, received the 2018-2019 Joseph Palais distinguished faculty award and the 2020-2021 Fulton Entrepreneurial Professor Fellowship. Her research aims to understand how intrinsic and extrinsic defects affect the electrical and optical properties of energy materials and accordingly engineer the processing steps that will maximize performance.
Thursday, March 25, 4:00-5:00 pm, on Zoom
Prof. Alan Van Orden (Colorado State Univ.)
New imaging techniques to explore energy and charge carrier transport in nanoparticles and nanoclusters
Abstract: This presentation will discuss new super-resolved imaging techniques to probe the dynamics of energy and charge carrier transport in nanoparticle and nanocluster higher-order structures. We have reported spatiotemporal imaging with nanometer scale spatial resolution and sub-nanosecond time resolution to image the dynamics of energy transfer within semiconductor nanoparticle assemblies. These images directly reveal the direction and efficiency of energy transport within the assembled nanoparticles on the nanometer scale. Applications to other types of nanoscale systems, including atomically precise metal nanoclusters, will also be discussed.
Bio: B.S. (cum laude), Chemistry, 1990, Brigham Young University, Provo, UT; Ph.D., Physical Chemistry (with Richard J. Saykally), 1996, University of California at Berkeley, Dissertation: Direct Infrared Laser Absorption Spectroscopy of Carbon and Silicon-Carbon Clusters; Postdoctoral Research Associate (with Richard A. Keller), 1996-1999, Los Alamos National Laboratory, Los Alamos, NM; Assistant Professor of Chemistry, 1999-2005, Associate Professor of Chemistry, 2005-2016, Professor of Chemistry, 2016- present, Colorado State University, Fort Collins, CO; Visiting Scholar (with Shie-Jie Chen), 2014-2015, University of Missouri Department of Physics, Columbia, MO; Faculty Guest Researcher, Los Alamos National Laboratory, Center for Integrated Nanotechnologies and Institute for Materials Science, Summer 2017, Spring 2021; Air Force Summer Faculty Fellow, Air Force Research Laboratory, Wright- Patterson Air Force Base, Dayton, OH, Summer 2019, 2020.
Thursday, March 18, 4:00-5:00 pm, on Zoom
Prof. Kyle F. Biegasiewicz (Arizona State Univ.)
- Assistant Professor of Chemistry
- School of Molecular Sciences
Chemical and Enzymatic Strategies for Complex Molecule Synthesis
Abstract: The chemical synthesis of structurally and stereochemically complex molecules is a focal point of the pharmaceutical, agriculture and materials industries. In an effort to optimize the desired parameters affiliated with their synthesis (step, atom, redox economies) we rely heavily upon the discovery of catalysts that can accomplish early and late-stage bond construction under mild conditions and with broad functional group tolerance. Moreover, a premium is placed on the development of sustainable catalysts that can accomplish these goals with little to no waste generation.
This talk will feature a combination of chemical and enzymatic strategies for achieving catalytic C-C bond formation. It will be divided into three segments including 1) the development of an organocatalytic hydroxymethylation protocol and its application in the total synthesis of the apoptosis inducer, (-)-rasfonin, 2) photoexcitation of flavoenzymes for stereoselective C-C bond formation, and 3) the development of a terpene cyclase using oxyanion hole catalysis in hydrolases.
Bio: Kyle F. Biegasiewicz received his B.S. in Chemistry from Niagara University in 2010. He subsequently moved to the University of Rochester for his doctoral studies working under the tutelage of Professor Robert K. Boeckman, Jr. in the research areas of natural product synthesis and organocatalytic methods development. Upon completion of his Ph.D. in 2016, he moved to Princeton University as a Postdoctoral Research Associate working with Professor Todd K. Hyster on the design of photoenzymatic strategies to address current challenges in radical-mediated synthesis. In January of 2020, Kyle became an Assistant Professor of Chemistry in the School of Molecular Science at Arizona State University. His research group aims to take advantage of the unique catalytic capabilities of underexplored enzyme classes to achieve rapid construction of complex molecular architectures and/or the selective installation of structural entities that are highly desired in early and late-stage organic synthesis.
Thursday, March 11, 4:00-5:00 pm, on Zoom
Prof. GiShawn Mance (Howard University)
- Assistant Professor of Psychology
- Licensed Clinical Psychologist
Understanding and Addressing the Impostor Syndrome in the Field of STEM
Abstract: Do you doubt your accomplishments or feel like a fraud? Are there times you think to yourself that you do not belong in STEM? Many students in the field of STEM experience anxiety surrounding their readiness and ability to successfully navigate their course of study. The academic/professional self-doubt and fear of being discovered as a “fraud” is known as Impostor Syndrome. It affects many and is often characterized by a feeling that one will be “found out” or that one “does not belong” in their respective field. This presentation will describe signs of imposter syndrome, explores the psychology of impostor syndrome, examine how it may affect students in STEM, and strategies of address it.
Bio: Dr. GiShawn Mance is an Assistant Professor of Psychology at Howard University and Licensed Clinical Psychologist. Her scholarly work focuses on culturally and contextually relevant school- and community-based mental health interventions for adolescents and young adults exposed to trauma. Her clinical specialty areas include, but are not limited to, adolescent mental health, psycho-educational assessments, executive functioning issues, complex trauma, and parent/child interactions, and mood disorders.
Dr. Mance has partnered with communities both domestically and internationally influencing
mental health practices and research. Currently, she partners with several charter schools and community agencies in Washington DC and Maryland on the NETWORK Project which examines chronic stress, trauma, coping, social support systems, and psychological symptoms amongst youth and young adults. Additionally, Dr. Mance’s Youth and Communities Research Lab is investigating race-related stress, cultural coping, and psychological symptoms amongst Black emerging adults. Dr. Mance has contributed to the national dialogue on race and/or mental health as a guest on WHUR, NPR, the Washington Post, National Geographic, and Yahoo.com.
Thursday, March 4, 4:00-5:00 pm, on Zoom
Prof. David K. Ferry (Arizona State Univ.)
- Regents’ Professor Emeritus
- School of Electrical, Computer, and Energy Engineering
Hot Carrier Solar Cells and Non-Equilibrium Phonons
Abstract: Hot carrier solar cells were predicted to surpass the Shockley-Queisser efficiency limit almost four decades ago. To achieve this required drastically reducing the energy loss to the optical phonons in electron and hole relaxation and extracting the hot carriers directly from the device. Unfortunately, these proposed cells have yet to succeed. Recently, a new approach was suggested and is being explored. In this talk, the general state of solar cells and hot carrier solar cells will be discussed. In addition, since control of the phonons is required, the general world of non-equilibrium phonons will be discussed.
Bio: Prof. Ferry received the B.S.E.E. and M.S.E.E. degrees from Texas Tech University, Lubbock, in 1962 and 1963, respectively, and the Ph.D. degree from the University of Texas (UT), Austin, in 1966. Following this, he was a National Science Foundation Postdoctoral Fellow in Vienna, Austria. From 1967 to 1973, he was a Faculty Member at Texas Tech University, and then joined the Office of Naval Research, Washington, DC. From 1977 to 1983, he was with Colorado State University at Fort Collins, where he served as Professor and Chair of the Department. He then joined Arizona State University (ASU), Tempe, where he served as Director of the Center for Solid State Electronics Research from 1983 to 1989, as Chair of Electrical Engineering from 1989 to 1992, and as Associate Dean for Research from 1993 to 1995. His research interests include transport physics and modeling of quantum effects in ultra-small semiconductor devices. He has published more than 800 refereed articles, books, book chapters, and conference publications. Dr. Ferry was selected as one of the first Regents’ Professors at ASU in 1988, and received the IEEE Cledo Brunetti Award for advances in nanoelectronics in 1999. He is a Fellow of the American Physical Society, the Institute of Electrical and Electronics Engineers, and the Institute of Physics (UK). He has also served as Editor of the Journal of Physics Condensed Matter and the Journal of Computational Electronics. He is an Admiral in the Texas Navy and a Tennessee Squire.
Thursday, February 25, 4:00-5:00 pm, on Zoom
Prof. Dan Wasserman (University of Texas Austin)
- Microelectronics Research Center
- Department of Electrical and Computer Engineering
All-Epitaxial Mid-IR Plasmonic Optoelectronics
Abstract: The mid-infrared (mid-IR) spectral range (loosely defined as the wavelengths between 3-30μm) has become a burgeoning and dynamic field of research for a variety of technologically vital applications. Nonetheless, the development of the mid-IR optical infrastructure still trails behind that of the shorter, more mature, telecom and visible wavelength ranges. This can be viewed as a drawback of mid-IR photonics research (more expensive, limited efficiency components and materials), or alternatively, as an opportunity. In particular, the mid-IR provides a design space where a wide range of engineered and intrinsic light matter interactions can be harnessed to develop a new generation of optical materials. In this talk, I will discuss recent work developing novel optoelectronic, all-dielectric, plasmonic and phononic materials, devices, and structures for mid-IR wavelength applications. In particular, I will discuss the range of phenomena which can be leveraged to demonstrate unique designer materials, mid-IR devices, and novel characterization techniques. I will focus on recent results demonstrating that all-epitaxial plasmonic materials can be integrated monolithically with quantum engineered optoelectronic materials for enhanced performance mid-IR detectors and emitters. Ultimately, I will make an effort to demonstrate that the mid-IR provides a unique materials playground for the exploration, and implementation, of a range of light-matter interactions.
Bio: Dan Wasserman is an Associate Professor of Electrical and Computer Engineering at the University of Texas Austin, where he is affiliated with the Microelectronics Research Center. Prof. Wasserman earned his Sc.B. degree in Engineering/Physics and History from Brown University in 1998, graduating Summa Cum Laude, Phi Beta Kappa, and with Honors. He attended graduate school at
Princeton University, earning a National Science Foundation Graduate Fellowship, and receiving his Master’s and Doctorate in Electrical Engineering in 2000 and 2004, respectively. Following his PhD, Dr. Wasserman was awarded a Princeton University Council on Science and Technology Post-Doctoral Fellowship, and spent the next years working on quantum cascade lasers and developing a hands-on optics course at Princeton. In 2007, Dr. Wasserman joined the University of Massachusetts Lowell faculty as an Assistant Professor in the Department of Physics and Applied Physics. In 2007, Prof. Wasserman joined the faculty of the Electrical and Computer
Engineering Department at the University of Illinois Urbana Champaign, in the Micro and Nanotechnology Lab, becoming an Associate Professor in 2015. In 2016, Professor Wasserman joined the University of Texas at Austin. Prof. Wasserman is the recipient of the NSF CAREER award and the AFOSR Young Investigator Award, as well as the UIUC Distinguished Promotion Award, and Teaching and Advising awards and commendations at UMass and Illinois. Prof. Wasserman was elected a Fellow of the Optical Society of America in 2018.
Thursday, February 18, 4:00-5:00 pm, on Zoom
Dr. M. Mozammel Hoque (NAU)
- Applied Physics and Materials Science
- ¡MIRA! the Center for Materials Interfaces in Research and Applications
Protein like noble base-side metallic clusters
Abstract: The ubiquitous Au144(-SR)60 and closely related compounds of core mass∼29 kDa are larger monolayer protected clusters (MPC) comprising 144 gold atoms and 60 thiolate ligands (-RS groups). During last quarter century (since 1996, when it was first identified) it has served innumerable investigations from physicochemical fundamentals in the quantum regime to practical applications in biomedicine, using various phases appropriate to the (R-group) termini properties. Very recently, Wu and co-workers achieved an unambiguous determination of the virus-like chiral-icosahedral symmetry of its Au–S core- and surface-structure. Despite these significance advances, certain practical considerations restricted its applicability. An extraordinary recent development is that ESI-MS allows all the coexisting species in solution to be precisely detected, revolutionizing research on smaller MPCs. The difficult electrospray ionization properties of the critical-size MPCs have so far precluded the full application of ESI-MS methods. Building on the advances by Ishida and co-workers in cationized (quat-terminated) R-groups, I have recently found a path to tertiary-amino thiolate-protected clusters with characteristic basic properties including pH-controlled ionization of terminal amino groups. In this seminar, I will discuss about the precision route to captamine-protected Au144(SR)60 clusters—accompanied by small quantities of its Au137 and Au130 byproducts and indications of somewhat larger (plasmonic) species—that promises to overcome these challenges due to its amphiphilic nature and solubility in both aqueous and organic phase upon contact with acid or base in the solution. I will also talk about the ESI-MS analysis that generates up to 8+ charge state without any special counterions or ion-pairing agents.
Bio: M. Mozammel Hoque currently working as a postdoctoral researcher in the department of Applied Physics and Material Science (APMS) & Center for Materials Interfaces in Research and Applications (¡MIRA!) at Northern Arizona University. Before
joining NAU he received his B.S. (honors) and M.S. in Applied Physics/Electronics from the University of Dhaka, Bangladesh in 2011 and PhD in Chemical/Physics from the UT San Antonio in 2019. His research focuses on base termini (cationic) noble metallic i.e.,
gold, and silver nanoclusters and its alloys. He has successfully synthesized for the first-time tertiary amine (di-methyl-amino-ethanethiol, DMAET) protected gold nanoclusters. This has been a major goal/challenge of research in the field of molecular/physical
chemistry, since 1998 (~20 years). Dr. Hoque also demonstrated that a precession electron diffraction (PED) method incorporated with the conventional transmission electron microscope (TEM) can be used to determine the crystalline structure of smaller nanoparticles, where X-ray based synchrotron experiences a limitation, or could be used as an alternative approach. His current research goals are to obtain pure samples of these cationic cluster mixtures into atomically precise compounds by thiol etching or solvent fractionation procedures; and, crystallization of the clusters to confirm the crystal structure of cationic Au144; use thermodynamic-control to reach the [326-, 90] class; introduce copper-rich variants for scaled production (large-scale applications); prepare thin-film crystals of controlled electronic states by Langmuir Blodgett (LB) method that should lead to the phase of new superconducting materials.
Thursday, February 11, 4:00-5:00 pm, on Zoom
Dr. Loreen R. Stromberg (Los Alamos Nat’l Labs)
- Physical Chemistry & Applied Spectroscopy
- Inorganic Isotope & Actinide Chemistry
Interfacing Biomarkers and Materials Science: applications for detection and therapeutics
Abstract: Materials play a critical role in the development of surfaces for detection of biological components. In order to achieve the requisite sensitivity and specificity in a target matrix, the interface between surfaces and biomarkers needs to strike a balance with the appropriate degree of biomimicry, functionality, and compatibility with the detection platform. To tune this important interface the biochemistry, physiological presentation, and the binding capacity of the receptors/ligands must be taken into consideration when designing the assay. Equally important to these aspects are the methods of detection, sample matrices, signal transduction schemes, and the end user. In this talk I will present examples of materials used to create detection surfaces for biomarkers and bacterial cells. Specifically, I will discuss a spectroscopic detection strategy for lipopolysaccharides and Shiga toxin and a label-free electrochemical graphene sensor for detection of Salmonella enterica serovar Typhimurium. In each example the characterization of the functional surface for the detection assay will be discussed along with representative data. The last example will examine attempts to create a functional surface to evaluate bacterial viability after applying a radioisotope as a therapeutic strategy to treat Pseudomonas aeruginosa infections. The talk will conclude with a brief discussion on the relevance of different detection strategies that drive technical adaption and innovation for new materials.
Bio: Dr. Loreen Stromberg is currently a Frederick Reines Distinguished Postdoctoral Fellow jointly appointed to the Physical Chemistry & Applied Spectroscopy and Inorganic Isotope & Actinide Chemistry groups at Los Alamos National Laboratory. Loreen enjoys interdisciplinary applied science, evidenced by her current projects that span assay development, alpha-emitter based anti-microbial therapeutics, and lipid biophysics. Loreen has a B.S. in Biochemistry and a Ph.D. in Biomedical Engineering, both from the University of New Mexico. After graduate school, Loreen worked as a postdoctoral researcher in mechanical engineering at Iowa State University developing biosensors for multiple biological targets using printed graphene nanostructured surfaces. Prior to joining LANL as a postdoctoral fellow, Loreen was the CEO and co-founder of the biotech startup NanoSpy, Inc., working to interface nanomaterials and microfluidics to create
marketable sensors for foodborne pathogen detection. Loreen is a co-inventor on multiple patents and has several peer-reviewed publications that highlight the breadth of her work. In 2019, Loreen represented Los Alamos National Laboratory in the Department of Energy’s Postdoctoral Elemental Science Slam Competition on Capitol Hill, where she skillfully wielded a
Mjölnir replica in front of Congressional Staffers to deliver an entertaining overview of her work with the radioactive element Thorium. However, the strength of Titanium overtook Mjölnir, and carried the win, which still mystifies everyone. Loreen loves a good science joke.
Thursday, February 4, 4:00-5:00 pm, on Zoom
Prof. Shadi A. Dayeh (Univ. of California, San Diego)
- Integrated Electronics and Biointerfaces Laboratory
- Department of Electrical and Computer Engineering
Mapping the Human Brain with High Spatiotemporal Resolution
Abstract: Electrophysiological recordings are the gold standard for interrogating the nervous system for diagnostic and therapeutic purposes. Such recordings with microelectrode arrays enable broadband and high spatiotemporal resolution but are conventionally limited to a small cortical coverage. However, large cortical coverage together with the high spatiotemporal resolution are needed to advance our understanding of diseased and normal brain function to be able to develop effective therapies. This talk will cover the development and clinical translation of UCSD’s multi-thousand channel platinum nanorod microelectrode arrays to map the human brain. We will discuss considerations in the electrode-tissue interface for recording and stimulation, and demonstrate mapping of functional units across species including humans. Examples of large-scale microelectrode mapping of motor, language, and epileptogenic discharges from the human brain will be presented along with a perspective on future directions.
Bio: Shadi Dayeh received his B.S. in Physics/Electronics from the Lebanese University in Beirut, Lebanon in 2001 and PhD in Electrical Engineering from UC San Diego in 2008. He was a Distinguished J. R. Oppenheimer Postdoctoral Fellow at Los Alamos National Laboratory where he co-led and expanded LANL’s nanowire program before joining the ECE faculty at UC San Diego in November 2012 where he is now a Professor.
His lab specializes in electronic material growth and devices and the utility of material and device advances to probe biological processes from cellular scales to whole intact organs.
Shadi’s work in electronic materials earned a number of best paper awards and the 2018 Young Scientist Award from the International Symposium on Compound Semiconductors which is given once per year to acknowledge significant achievements in the field of compound semiconductors by a scientist younger than 40 years.
After joining UCSD, Shadi’s research pivoted to translational neurotechnologies which was supported by UCSD’s center for brain activity mapping, an NSF early CAREER Award, a scalable nanomanufacturing award from the NSF, and currently with the 2019 NIH Director’s New Innovator Award.
Shadi led the development of the UCSD multi-thousand channel grids that have revealed microscopic functional units of the human brain and spinal cord.