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- Materials Science and Engineering Faculty Publications and Presentations (15)
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Articles 1 - 21 of 21
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Formulation And Aerosol Jet Printing Of Nickel Nanoparticle Ink For High-Temperature Microelectronic Applications And Patterned Graphene Growth, Nicholas Mckibben, Michael Curtis, Olivia Maryon, Mone’T Sawyer, Maryna Lazouskaya, Josh Eixenberger, Zhangxian Deng, David Estrada
Formulation And Aerosol Jet Printing Of Nickel Nanoparticle Ink For High-Temperature Microelectronic Applications And Patterned Graphene Growth, Nicholas Mckibben, Michael Curtis, Olivia Maryon, Mone’T Sawyer, Maryna Lazouskaya, Josh Eixenberger, Zhangxian Deng, David Estrada
Materials Science and Engineering Faculty Publications and Presentations
Aerosol jet printing (AJP) is an advanced manufacturing technique for directly writing nanoparticle inks onto target substrates. It is an emerging reliable, efficient, and environmentally friendly fabrication route for thin film electronics and advanced semiconductor packaging. This fabrication technique is highly regarded for its rapid prototyping, the flexibility of design, and fine feature resolution. Nickel is an attractive high-temperature packaging material due to its electrical conductivity, magnetism, and corrosion resistance. In this work, we synthesized nickel nanoparticles and formulated an AJP ink, which was printed on various material surfaces. Thermal sintering experiments were performed on the samples to explore the …
Correlative Imaging Of Three-Dimensional Cell Culture On Opaque Bioscaffolds For Tissue Engineering Applications, Mone’T Sawyer, Josh Eixenberger, Olivia Nielson, Jacob Manzi, Cadré Francis, Raquel Montenegro-Brown, Harish Subbaraman, David Estrada
Correlative Imaging Of Three-Dimensional Cell Culture On Opaque Bioscaffolds For Tissue Engineering Applications, Mone’T Sawyer, Josh Eixenberger, Olivia Nielson, Jacob Manzi, Cadré Francis, Raquel Montenegro-Brown, Harish Subbaraman, David Estrada
Materials Science and Engineering Faculty Publications and Presentations
Three-dimensional (3D) tissue engineering (TE) is a prospective treatment that can be used to restore or replace damaged musculoskeletal tissues, such as articular cartilage. However, current challenges in TE include identifying materials that are biocompatible and have properties that closely match the mechanical properties and cellular microenvironment of the target tissue. Visualization and analysis of potential 3D porous scaffolds as well as the associated cell growth and proliferation characteristics present additional problems. This is particularly challenging for opaque scaffolds using standard optical imaging techniques. Here, we use graphene foam (GF) as a 3D porous biocompatible substrate, which is scalable, reproducible, …
Tunable Electronic Structure Via Dna-Templated Heteroaggregates Of Two Distinct Cyanine Dyes, Jonathan S. Huff, Matthew S. Barclay, Azhad U. Chowdhury, Lance K. Patten, Simon K. Roy, Aaron Sup, Austin Biaggne, Lan Li, Jeunghoon Lee, Paul H. Davis, Bernard Yurke, William B. Knowlton, Daniel B. Turner, Ryan D. Pensack
Tunable Electronic Structure Via Dna-Templated Heteroaggregates Of Two Distinct Cyanine Dyes, Jonathan S. Huff, Matthew S. Barclay, Azhad U. Chowdhury, Lance K. Patten, Simon K. Roy, Aaron Sup, Austin Biaggne, Lan Li, Jeunghoon Lee, Paul H. Davis, Bernard Yurke, William B. Knowlton, Daniel B. Turner, Ryan D. Pensack
Materials Science and Engineering Faculty Publications and Presentations
Molecular excitons are useful for applications in light harvesting, organic optoelectronics, and nanoscale computing. Electronic energy transfer (EET) is a process central to the function of devices based on molecular excitons. Achieving EET with a high quantum efficiency is a common obstacle to excitonic devices, often owing to the lack of donor and acceptor molecules that exhibit favorable spectral overlap. EET quantum efficiencies may be substantially improved through the use of heteroaggregates─aggregates of chemically distinct dyes─rather than individual dyes as energy relay units. However, controlling the assembly of heteroaggregates remains a significant challenge. Here, we use DNA Holliday junctions to …
Zinc–Acetate–Amine Complexes As Precursors To Zno And The Effect Of The Amine On Nanoparticle Morphology, Size, And Photocatalytic Activity, Josh Eixenberger, David Estrada
Zinc–Acetate–Amine Complexes As Precursors To Zno And The Effect Of The Amine On Nanoparticle Morphology, Size, And Photocatalytic Activity, Josh Eixenberger, David Estrada
Materials Science and Engineering Faculty Publications and Presentations
Zinc oxide is an environmentally friendly and readily synthesized semiconductor with many industrial applications. ZnO powders were prepared by alkali precipitation using different [Zn(acetate)2(amine)x] compounds to alter the particle size and aspect ratio. Slow precipitations from 95 °C solutions produced micron-scale particles with morphologies of hexagonal plates, rods, and needles, depending on the precursor used. Powders prepared at 65 °C with rapid precipitation yielded particles with minimal morphology differences, but particle size was dependent on the precursor used. The smallest particles were produced using precursors that yielded crystals with low aspect ratios during high-temperature synthesis. Particles …
Electrochemically Induced Amorphous-To-Rock-Salt Phase Transformation In Niobium Oxide Electrode For Li-Ion Batteries, Pete Barnes, Yunxing Zuo, Kiev Dixon, Dewen Hou, Sungsik Lee, Zhiyuan Ma, Justin G. Connell, Hua Zhou, Changjian Deng, Kassiopeia Smith, Eric Gabriel, Yuzi Liu, Olivia O. Maryon, Paul H. Davis, Haoyu Zhu, Yingge Du, Ji Qi, Zhuoying Zhu, Chi Chen, Zihua Zhu, Yadong Zhou, Paul J. Simmonds, Ariel E. Briggs, Darin Schwartz, Shyue Ping Ong, Hui Xiong
Electrochemically Induced Amorphous-To-Rock-Salt Phase Transformation In Niobium Oxide Electrode For Li-Ion Batteries, Pete Barnes, Yunxing Zuo, Kiev Dixon, Dewen Hou, Sungsik Lee, Zhiyuan Ma, Justin G. Connell, Hua Zhou, Changjian Deng, Kassiopeia Smith, Eric Gabriel, Yuzi Liu, Olivia O. Maryon, Paul H. Davis, Haoyu Zhu, Yingge Du, Ji Qi, Zhuoying Zhu, Chi Chen, Zihua Zhu, Yadong Zhou, Paul J. Simmonds, Ariel E. Briggs, Darin Schwartz, Shyue Ping Ong, Hui Xiong
Materials Science and Engineering Faculty Publications and Presentations
Intercalation-type metal oxides are promising negative electrode materials for safe rechargeable lithium-ion batteries due to the reduced risk of Li plating at low voltages. Nevertheless, their lower energy and power density along with cycling instability remain bottlenecks for their implementation, especially for fast-charging applications. Here, we report a nanostructured rock-salt Nb2O5 electrode formed through an amorphous-to-crystalline transformation during repeated electrochemical cycling with Li+. This electrode can reversibly cycle three lithiums per Nb2O5, corresponding to a capacity of 269 mAh g−1 at 20 mA g−1, and retains a capacity …
Tuning Between Quenching And Energy Transfer In Dna-Templated Heterodimer Aggregates, Azhad U. Chowdhury, Jonathan S. Huff, Matthew S. Barclay, Lance K. Patten, Aaron Sup, Natalya Hallstrom, Jeunghoon Lee, Paul H. Davis, Daniel B. Turner, Bernard Yurke, William B. Knowlton, Ryan D. Pensack
Tuning Between Quenching And Energy Transfer In Dna-Templated Heterodimer Aggregates, Azhad U. Chowdhury, Jonathan S. Huff, Matthew S. Barclay, Lance K. Patten, Aaron Sup, Natalya Hallstrom, Jeunghoon Lee, Paul H. Davis, Daniel B. Turner, Bernard Yurke, William B. Knowlton, Ryan D. Pensack
Materials Science and Engineering Faculty Publications and Presentations
Molecular excitons, which propagate spatially via electronic energy transfer, are central to numerous applications including light harvesting, organic optoelectronics, and nanoscale computing; they may also benefit applications such as photothermal therapy and photoacoustic imaging through the local generation of heat via rapid excited-state quenching. Here we show how to tune between energy transfer and quenching for heterodimers of the same pair of cyanine dyes by altering their spatial configuration on a DNA template. We assemble “transverse” and “adjacent” heterodimers of Cy5 and Cy5.5 using DNA Holliday junctions. We find that the transverse heterodimers exhibit optical properties consistent with excitonically interacting …
Tensile-Strained Self-Assembly Of Ingaas On Inas(111)A, Kevin D. Vallejo, Trent A. Garrett, Carlos I. Cabrera, Baolai Liang, Kevin A. Grossklaus, Paul J. Simmonds
Tensile-Strained Self-Assembly Of Ingaas On Inas(111)A, Kevin D. Vallejo, Trent A. Garrett, Carlos I. Cabrera, Baolai Liang, Kevin A. Grossklaus, Paul J. Simmonds
Materials Science and Engineering Faculty Publications and Presentations
We have determined a reproducible set of growth conditions for the self-assembly of tensile-strained In1-xGaxAs quantum dot (QD) nanostructures on (111)A surfaces. During molecular beam epitaxy, In1-xGaxAs islands form spontaneously on InAs(111)A when the Ga content x ≥ 50%. We analyze the structure and composition of InGaAs/InAs(111) samples using atomic force microscopy, transmission electron microscopy, and electron energy loss spectroscopy. We demonstrate control over the size and areal density of the islands as a function of In1-xGaxAs coverage, In1-xGaxAs composition, …
Nuclear Envelope Mechanobiology: Linking The Nuclear Structure And Function, Matthew Goelzer, Julianna Goelzer, Matthew L. Ferguson, Corey P. Neu, Gunes Uzer
Nuclear Envelope Mechanobiology: Linking The Nuclear Structure And Function, Matthew Goelzer, Julianna Goelzer, Matthew L. Ferguson, Corey P. Neu, Gunes Uzer
Mechanical and Biomedical Engineering Faculty Publications and Presentations
The nucleus, central to cellular activity, relies on both direct mechanical input as well as its molecular transducers to sense external stimuli and respond by regulating intra-nuclear chromatin organization that determines cell function and fate. In mesenchymal stem cells of musculoskeletal tissues, changes in nuclear structures are emerging as a key modulator of their differentiation and proliferation programs. In this review we will first introduce the structural elements of the nucleoskeleton and discuss the current literature on how nuclear structure and signaling are altered in relation to environmental and tissue level mechanical cues. We will focus on state-of-the-art techniques to …
Adsorption And Surface Diffusion Of Metals On Α-Al2O3 For Advanced Manufacturing Applications, Austin Biaggne, Gregory Noble, Lan Li
Adsorption And Surface Diffusion Of Metals On Α-Al2O3 For Advanced Manufacturing Applications, Austin Biaggne, Gregory Noble, Lan Li
Materials Science and Engineering Faculty Publications and Presentations
The adsorption and diffusion of Mo and Nb adatoms on the α-Al2O3 (0001) surface were explored using density functional theory-based methods. Adsorption energies of Mo and Nb adatoms at minima sites on the surface were determined. Mo and Nb adatoms prefer to adsorb to the same locations on the surface, and larger adsorption energies calculated for Nb compared to Mo indicate that Nb adatom-surface interactions are stronger than Mo. Using minima adsorption sites as initial and final locations for surface diffusion, energy barriers for diffusion were calculated using the nudged elastic band method. Overall, Mo and …
Interface Structure And Luminescence Properties Of Epitaxial Pbse Films On Inas(111)A, Kevin D. Vallejo, Paul J. Simmonds
Interface Structure And Luminescence Properties Of Epitaxial Pbse Films On Inas(111)A, Kevin D. Vallejo, Paul J. Simmonds
Materials Science and Engineering Faculty Publications and Presentations
Epitaxial heterostructures of narrow-gap IV-VI and III-V semiconductors offer a platform for new electronics and mid-infrared photonics. Stark dissimilarities in the bonding and the crystal structure between the rocksalt IV–VIs and the zincblende III–Vs, however, mandate the development of nucleation and growth protocols to reliably prepare high-quality heterostructures. In this work, we demonstrate a route to single crystal (111)-oriented PbSe epitaxial films on nearly lattice-matched InAs (111)A templates. Without this technique, the high-energy heterovalent interface readily produces two populations of PbSe grains that are rotated 180° in-plane with respect to each other, separated by rotational twin boundaries. We find that …
Influence Of The Inas Coverage On The Performance Of Submonolayer-Quantum-Dot Infrared Photodetectors Grown With A (2×4) Surface Reconstruction, Ahmad Alzeidan, Tiago F. De Cantalice, Kevin D. Vallejo, Paul J. Simmonds, Alain A. Quivy
Influence Of The Inas Coverage On The Performance Of Submonolayer-Quantum-Dot Infrared Photodetectors Grown With A (2×4) Surface Reconstruction, Ahmad Alzeidan, Tiago F. De Cantalice, Kevin D. Vallejo, Paul J. Simmonds, Alain A. Quivy
Materials Science and Engineering Faculty Publications and Presentations
Two infrared photodetectors based on submonolayer quantum dots, having a different InAs coverage of 35% and 50%, were grown, processed and tested. The detector with the larger coverage yielded a specific detectivity of 1.13×10 11 cm Hz 1/2 W -1 at 12K, which is among the highest values reported in the literature for that kind of device.
Impact Of Arsenic Species On Self-Assembly Of Triangular And Hexagonal Tensile-Strained Gaas(111)A Quantum Dots, Christopher F. Schuck, Kevin D. Vallejo, Trent Garrett, Qing Yuan, Ying Wang, Baolai Liang, Paul J. Simmonds
Impact Of Arsenic Species On Self-Assembly Of Triangular And Hexagonal Tensile-Strained Gaas(111)A Quantum Dots, Christopher F. Schuck, Kevin D. Vallejo, Trent Garrett, Qing Yuan, Ying Wang, Baolai Liang, Paul J. Simmonds
Materials Science and Engineering Faculty Publications and Presentations
We use dimeric arsenic (As2) or tetrameric arsenic (As4) during molecular beam epitaxy to manipulate the structural and optical properties of GaAs(111)A tensile-strained quantum dots (TSQDs). Choice of arsenic species affects nucleation and growth behavior during TSQD self-assembly. Previously, epitaxial GaAs(111)A TSQDs have been grown with As4, producing TSQDs with a triangular base, and 'A-step' edges perpendicular to the three 1̅1̅2 directions. We demonstrate that using As2 at low substrate temperature also results in triangular GaAs(111)A TSQDs, but with 'B-step' edges perpendicular to the three 112̅ directions. We can therefore invert the crystallographic …
Tensile-Strained Self-Assembly: Tunable Nanomaterials For Infrared Optoelectronics And Quantum Optics, Paul Simmonds
Tensile-Strained Self-Assembly: Tunable Nanomaterials For Infrared Optoelectronics And Quantum Optics, Paul Simmonds
Materials Science and Engineering Faculty Publications and Presentations
Discovered recently, tensile-strained quantum dots are optically active, defect-free nanostructures. Large tensile strains allow us to tailor band structures for applications from tunable infrared emitters to entangled photon sources. I will discuss the history, current state-of-the-art, and future directions of this rapidly expanding research field.
Anomalous Stranski-Krastanov Growth Of (111)-Oriented Quantum Dots With Tunable Wetting Layer Thickness, Christopher F. Schuck, Simon K. Roy, Trent Garrett, Paul J. Simmonds
Anomalous Stranski-Krastanov Growth Of (111)-Oriented Quantum Dots With Tunable Wetting Layer Thickness, Christopher F. Schuck, Simon K. Roy, Trent Garrett, Paul J. Simmonds
Materials Science and Engineering Faculty Publications and Presentations
Driven by tensile strain, GaAs quantum dots (QDs) self-assemble on In0.52Al0.48As(111)A surfaces lattice-matched to InP substrates. In this study, we show that the tensile-strained self-assembly process for these GaAs(111)A QDs unexpectedly deviates from the well-known Stranski-Krastanov (SK) growth mode. Traditionally, QDs formed via the SK growth mode form on top of a flat wetting layer (WL) whose thickness is fixed. The inability to tune WL thickness has inhibited researchers’ attempts to fully control QD-WL interactions in these hybrid 0D-2D quantum systems. In contrast, using microscopy, spectroscopy, and computational modeling, we demonstrate that for GaAs(111)A QDs, we …
Inas(111)A Homoepitaxy With Molecular Beam Epitaxy, Kevin D. Vallejo, Trent A. Garrett, Kathryn E. Sautter, Kevin Saythavy, Baolai Liang, Paul J. Simmonds
Inas(111)A Homoepitaxy With Molecular Beam Epitaxy, Kevin D. Vallejo, Trent A. Garrett, Kathryn E. Sautter, Kevin Saythavy, Baolai Liang, Paul J. Simmonds
Materials Science and Engineering Faculty Publications and Presentations
The authors have established a robust set of growth conditions for homoepitaxy of high-quality InAs with a (111)A crystallographic orientation by molecular beam epitaxy (MBE). By tuning the substrate temperature, the authors obtain a transition from a 2D island growth mode to step-flow growth. Optimized MBE parameters (substrate temperature = 500 °C, growth rate = 0.12ML/s, and V/III ratio ≥ 40) lead to the growth of extremely smooth InAs(111)A films, free from hillocks and other 3D surface imperfections. The authors see a correlation between InAs surface smoothness and optical quality, as measured by photoluminescence spectroscopy. This work establishes InAs(111)A as …
Self-Assembly Of (111)-Oriented Tensile-Strained Quantum Dots By Molecular Beam Epitaxy, Christopher F. Schuck, Robin A. Mccown, Ashlie Hush, Austin Mello, Simon Roy, Joseph W. Spinuzzi, Paul J. Simmonds
Self-Assembly Of (111)-Oriented Tensile-Strained Quantum Dots By Molecular Beam Epitaxy, Christopher F. Schuck, Robin A. Mccown, Ashlie Hush, Austin Mello, Simon Roy, Joseph W. Spinuzzi, Paul J. Simmonds
Materials Science and Engineering Faculty Publications and Presentations
The authors report on a comprehensive study of the growth of coherently strained GaAs quantum dots (QDs) on (111) surfaces via the Stranski–Krastanov (SK) self-assembly mechanism. Recent reports indicate that the long-standing challenges, whereby the SK growth mechanism could not be used to synthesize QDs on (111) surfaces, or QDs under tensile strain, have been overcome. However, a systematic study of the SK growth of (111)-oriented, tensile-strained QDs (TSQDs) as a function of molecular beam epitaxy growth parameters is still needed. Here, the authors explore the effects of deposition amount, substrate temperature, growth rate, and V/III flux ratio on the …
Serum Proteins Enhance Dispersion Stability And Influence The Cytotoxicity And Dosimetry Of Zno Nanoparticles In Suspension And Adherent Cancer Cell Models, Catherine B. Anders, Jordan J. Chess, Denise G. Wingett, Alex Punnoose
Serum Proteins Enhance Dispersion Stability And Influence The Cytotoxicity And Dosimetry Of Zno Nanoparticles In Suspension And Adherent Cancer Cell Models, Catherine B. Anders, Jordan J. Chess, Denise G. Wingett, Alex Punnoose
Biomolecular Research Center Publications and Presentations
Agglomeration and sedimentation of nanoparticles (NPs) within biological solutions is a major limitation in their use in many downstream applications. It has been proposed that serum proteins associate with the NP surface to form a protein corona that limits agglomeration and sedimentation. Here, we investigate the effect of fetal bovine serum (FBS) proteins on the dispersion stability, dosimetry, and NP-induced cytotoxicity of cationic zinc oxide nanoparticles (nZnO) synthesized via forced hydrolysis with a core size of 10 nm. Two different in vitro cell culture models, suspension and adherent, were evaluated by comparing a phosphate buffered saline (PBS) nZnO dispersion (nZnO/PBS) …
Ion Beam Effect On Ge-Se Chalcogenide Glass Films: Non-Volatile Memory Array Formation, Structural Changes And Device Performance, M. R. Latif, T. L. Nichol, M. Mitkova, D. A. Tenne, I. Csarnovics, S. Kokenyesi, A. Csik
Ion Beam Effect On Ge-Se Chalcogenide Glass Films: Non-Volatile Memory Array Formation, Structural Changes And Device Performance, M. R. Latif, T. L. Nichol, M. Mitkova, D. A. Tenne, I. Csarnovics, S. Kokenyesi, A. Csik
Electrical and Computer Engineering Faculty Publications and Presentations
In this work a scheme for fabricating a conductive bridge non-volatile memory arrays, using ion bombardment through a mask, is demonstrated. Blanket films and devices have been created to study the structural changes, surface roughness and device performance. Ar+ ions interaction on thin films of GexSe1−x system have been studied using Raman Spectroscopy, Atomic Force Microscopy (AFM) and Energy Dispersive X-Ray Spectroscopy (EDS). The performance of the memory devices has been analyzed based on the formation of vias and damage accumulation due to Ar+ ion interactions with GexSe1−x(x=0.25, 0.3 and 0.4) …
Structural Study Of Ag-Ge-S Solid Electrolyte Glass System For Resistive Radiation Sensing, Ping Chen, Mahesh Ailavajhala, Maria I. Mitkova, Dmitri A. Tenne, Ivan Sanchez Esqueda, Hugh Barnaby
Structural Study Of Ag-Ge-S Solid Electrolyte Glass System For Resistive Radiation Sensing, Ping Chen, Mahesh Ailavajhala, Maria I. Mitkova, Dmitri A. Tenne, Ivan Sanchez Esqueda, Hugh Barnaby
Electrical and Computer Engineering Faculty Publications and Presentations
Solid electrolytes based on chalcogenide glasses have been one of the most promising candidates for the next generation non-volatile memories. Here we propose a new application of chalcogenide solid electrolytes for low cost, high performance microelectronic radiation sensor that reacts to γ-radiation to produce an easily measurable change in electrical resistance. The active layer material is Ag-doped GeS thin film glasses and several compositions of GeS base glasses were tested for best resistive sensing capability. Energy-dispersive X-ray spectroscopy (EDS) was used for elemental analysis and Raman scattering spectroscopy was measured to determine the structural details and radiation induced structural changes. …
Against Realist Instruction: Superficial Success Masking Catastrophic Failure And An Alternative, Dewey I. Dykstra
Against Realist Instruction: Superficial Success Masking Catastrophic Failure And An Alternative, Dewey I. Dykstra
Physics Faculty Publications and Presentations
Purpose: Often radical constructivists are confronted with arguments why radical constructivism is wrong. The present work presents a radical constructivist alternative to such arguments: a comparison of the results of two instructional practices, the standard, realistbased instruction and a radical constructivist-based instruction, both in physics courses. Design: Evidence from many studies of student conceptions in standard instruction (Duit 2004) is taken into account. In addition, diagnostic data, pre and post instruction, were collected from over 1,000 students in multiple institutions across the U. S. over a period of about 15 years via an established diagnostic of conceptual understanding of motion …
How We Think About And Prepare To Teach Physics, Dewey I. Dykstra
How We Think About And Prepare To Teach Physics, Dewey I. Dykstra
Physics Faculty Publications and Presentations
We have been preparing physics teachers in the same manner for many decades. Yet, physics education research reveals for some observers disturbing evidence of little or no change in understanding the phenomena occurs as a direct result of physics instruction from elementary school through the college years. The apparent compatibility between these learning results and prevailing paradigm enables the construction of a description the paradigm. If it can be demonstrated that there is even just one alternative paradigm from which powerful alternative pedagogical practice is derived, are we not obligated to change how we prepare to teach physics?