Nanoscience and Nanotechnology Commons^™

Bioengineering Of An In Vitro Microphysiological Human Alveolar Model, Ayesha Arefin

Nanoscience and Microsystems ETDs

Drugs tested on animal models do not always produce the same results in humans; a reliable in vitro lung model can bridge the divide between the two. Because the alveolus is a target for several drugs, an alveolar model can be a platform for both designing drugs and studying lung diseases. A model should allow for gas exchange, growth of primary alveolar epithelial cells, extracellular matrix production, and have similar mechanical properties to alveoli, creating an environment conducive to normal metabolic activity and cellular responses. Existing artificial alveolar models that use polymeric membranes to sustain lung cells are limited by …

Spectro-Electrochemical Platforms For Dynamic Analyses Of Catalytic Cascade Systems, Nalin I. Andersen

Nanoscience and Microsystems ETDs

The development of spectro-electrochemical platforms that facilitate the dynamic analyses of complex catalytic cascade systems was explored in this research. These systems facilitated multiple modalities of catalysts and were used as platforms for monitoring catalytic transformations quasi-in situ. The analytical platforms allowed for the characterization of intermediates and products using surface-enhanced Raman spectroscopy (SERS). The design and fabrication of these devices proved to be reproducible, made of materials that can be manipulated for multiple applications, and incorporate fluid mechanics, electrochemistry, and multimodal catalysis. Microfluidic technology offers capabilities for understanding catalytic cascade systems by providing precise dynamic control of …

From Flasks To Applications: Design And Optimization Of Giant Quantum Dots Using Traditional And Automated Synthetic Methods, Christina J. Hanson

Nanoscience and Microsystems ETDs

Semiconducting nanocrystals, also known as quantum dots (QDs), that emit light with near-unity quantum yield and are extremely photostable are attractive options as down-conversion and direct electricity-to-light materials for a variety of applications including solid-state lighting, display technologies, bio-imaging and optical tracking. Standard QDs with a core/thin shell structure display fluorescence intermittency (blinking) and photobleaching when exposed to prolonged room temperature excitation for single dot measurements, as well as significant reabsorption and energy transfer when densely packed into polymers or at high solution concentrations.

We have developed thick shell “giant” QDs (gQDs), ultra-stable photon sources both at the ensemble and …

The Processing And Polarization Reversal Dynamics Of Thin Film Poly(Vinylidene) Fluoride, Noel Mayur Dawson

Nanoscience and Microsystems ETDs

Many ferroelectric devices benefit from the ability to deposit thin ferroelectric layers. Poly(vinylidene) fluoride (PVDF) is the prototypical ferroelectric polymer, but processing of thin film ferroelectric PVDF remains a challenge due to the formation of large voids in the film during traditional thin film processing. The research described in this dissertation starts by investigating the origin of these voids. The cause of these voids is found to be caused by vapor induced phase separation (VIPS). Guided by the thermodynamics of VIPS, a process is then designed to produce void-free ferroelectric PVDF thin films on polar and non-polar substrates. The films …

Incorporation Of Catalytic Modalities For Forming Of A Catalytic Cascade, Albert T. Perry Iii

Nanoscience and Microsystems ETDs

This dissertation investigates the novel incorporation of inorganic and enzymatic catalysts. There is little literature on inorganic catalysts operating at biologically relevant pHs and as such a significant amount of this dissertation focuses on determination of catalyst activity. Mn amino-anitpyrene (MnAAPyr), Pt, Pt alloys, Mn-N-C and Pd catalysts on 3D graphene supports(3D-GNS), were explored for activity towards glycerol intermediates: oxalic acid, mesoxalic acid, glyoxalic acid, and formic acid. MnAAPyr was designed to mimic the reaction center of oxalate decarboxylase and oxalate oxidaze, the natural catalyst towards oxalic acid. It showed high activity towards oxalic acid, with onset potentials of 0.714±0.002V …

Ion Size Effects On The Properties Of Charge Regulating Electric Double Layers, Divya Jyoti Prakash

Nanoscience and Microsystems ETDs

The behavior of charged interfaces formed in various systems like colloidal solution, fuel cells, battery, electro-deposition, catalysis is governed by the properties of electrical double layer(EDL). Civilized model with charge regulation boundary condition determined by thermodynamic equilibrium at the interface has been used to model electrical double layer and shows that size of the solvent plays a critical role in characterizing the properties of EDL using classical density functional theory.This thesis investigates the impact of ion size in electrolyte solutions on the electrical double layer formed at the interface using a similar model. It is found that ion size greatly …

Copper Electrodeposition In Mesoscale Through-Silicon-Vias, Lyle Alexander Menk

Nanoscience and Microsystems ETDs

Copper (Cu) electrodeposition (ECD) in through-silicon-vias (TSVs) is an essential technique required for high-density 3-D integration of complex semiconductor devices. The importance of Cu ECD in damascene interconnects has led to a natural development towards copper electrodeposition in TSVs. Cu ECD is preferred over alternative approaches like the chemical vapor deposition (CVD) of tungsten (W) or aluminum (Al) because Cu ECD films have lower film stress, lower processing temperatures, and more optimal thermal and electrical properties as compared with CVD W or Al.

Via filling with electroplated Cu on substrates that have undergone atomic layer deposition of a conformal platinum …

Graphite And Graphene-Oxide Based Pgm-Free Model Catalysts For The Oxygen Reduction Reaction, Joseph Henry Dumont

Nanoscience and Microsystems ETDs

The world currently relies heavily on fossil fuels such as coal, oil, and natural gas for its energy. Fossil fuels are non-renewable, that is, they draw on finite resources that will eventually dwindle, becoming too expensive or too environmentally damaging to retrieve. One alternative source of energy are fuel cells, electrochemical devices that convert chemical energy to cleanly and efficiently produce electricity. They can be used in a wide range of applications, including transportation, stationary, portable and emergency power sources. Their development has been slowed by the high cost of PGM electrocatalysts needed at both electrodes as well as sluggish …

Waveguide-Coupled Avalanche Photodiodes For A Cmos Compatible Tranceiver Package, Nick Martinez

Nanoscience and Microsystems ETDs

Optical signal detection is most readily done with classical sources emitting signals

which undergo very little attenuation. Detection of signals with these power levels

benets from classical photodetectors, where the photon induced electronic signal is

discernible above the background noise. In other instances, where the optical signal

may start from an attenuated source, or in cases where the optical signal is severely

attenuated in transit, a detector which exhibits gain converts a weak optical signal

into a measurable electrical one. Detectors which convert a weak photo-generated

electrical pulse into a strong one do so through a process known as carrier …

Role Of Vapor Phase Processes On The Sintering Of Diesel Oxidation Catalysts, Cristhian Carrillo

Nanoscience and Microsystems ETDs

This work provides a fundamental understanding on the vapor phase processes that govern the sintering of supported nanoparticles in relation to the diesel oxidation catalyst (DOC). Sintering is a deactivation process that affects this catalyst significantly, and many other catalyst systems. Therefore, it is important to understand the sintering mechanisms in order to improve the long term catalytic reactivity.

Pt is an active catalyst in the DOC but it sinters via Ostwald ripening to form large particles under the accelerated aging conditions (800 ^oC) recommended by the Department of Energy (DOE). At 800 ^oC in the presence of …

Study Of Polysulfide Speciation In Lithium Sulfur Batteries Using In Situ Confocal Raman Microscopy, Josefine Mcbrayer

Nanoscience and Microsystems ETDs

Secondary lithium sulfur (Li-S) batteries have been heavily studied in the battery community since the start of the 21^st century due to their high theoretical capacity and specific energy density. The ground-breaking lithium ion battery has revolutionized society and its ability to store energy, however the lithium ion battery is reaching its limit with a theoretical capacity almost five times lower than that of lithium sulfur. With the improvement and commercialization of Li-S batteries, electric vehicles and personal electronics will have extended performance on a single charge. The viability of this promising chemistry relies on overcoming several key difficulties, …

A Study Of Dislocation Networks In Gasb On Gaas Using Transmission Electron Microscopy, Darryl M. Shima

Nanoscience and Microsystems ETDs

The growth of GaSb on GaAs is of interest for a variety of scientific and technological applications. Some evidence suggests that low threading dislocation density GaSb can be grown directly on GaAs through arrays of periodic edge misfit dislocations. However, significant conflicting data also exist. This work seeks to clarify the question through transmission electron microscopy analysis of GaSb grown on GaAs. The results of this work show that the single strategy of direct growth of GaSb on GaAs results in dislocation densities too high for devices. A secondary strategy of dislocation filtering layers is introduced to further reduce threading …

Dna Directed Assembly Of Gold-Tipped Metallic Single-Walled Carbon Nanotubes Into Electrical Devices, Ronald D. Salesky

Nanoscience and Microsystems ETDs

Carbon nanotubes have rightfully been regarded as a wonder material since their discovery by Iijima in 1991 and the subsequent elucidation of their many material properties. Their extreme strength is 10-fold higher than any industrial fiber. Their current density carrying capability is orders of magnitude higher than copper without failure from electromigration. Their high thermal conductivity bests diamond, and their structural versatility leads to either semiconducting or metallic electronic character. These properties all make the integration of carbon nanotubes into functional devices of high value. However, they remain a material of largely unrealized potential due to several challenges that arise …

A Study Of Iron-Nitrogen-Carbon Fuel Cell Catalysts: Chemistry – Nanostructure – Performance, Michael J. Workman

Nanoscience and Microsystems ETDs

Fuel cells have the potential to be a pollution-free, low-cost, and energy efficient alternative to the internal combustion engine for transportation and small-scale stationary power applications. The current state of fuel cell technology has already achieved two of these three lofty goals. The remaining barrier to wide-scale deployment is the high cost, which is primarily caused by dependence on large amounts of platinum to catalyze the energy conversion reactions. To overcome this barrier and facilitate the integration of fuel cells into mainstream applications, research into a new class of catalyst materials that do not require platinum is needed.

There has …

Measurement And Analysis Of Iii-V & Ii-Vi Infrared Detectors: Radiometric, Noise Spectrum, And Radiation Tolerance Performance, Vincent M. Cowan

Nanoscience and Microsystems ETDs

Infrared (IR) hybrid detector arrays and discrete detectors operated in the space environment may be subjected to a variety of sources of natural radiation while in orbit. This means IR detectors intended for applications such as space-based intelligence, surveillance, and reconnaissance (ISR) or space-situational awareness (SSA) must not only have high performance (high quantum efficiency, h and low dark-current density, J_D, and preferably minimal 1/f noise content), but also their radiation tolerance or ability to withstand the effects of the radiation they would expect to encounter in space must be characterized and well understood. As the effects of …

Applied Photoproperties Of Phenylene Ethynylenes, Patrick L. Donabedian

Nanoscience and Microsystems ETDs

Light-absorbing molecules can be used as powerful tools to perturb and understand biological systems by fluorescence, sensitization, or photochemical reactions. A thorough understanding of the delivery of dyes to specific biochemical targets and the processes that control the fate of excited-state energy is needed to engineer useful technology out of organic photochemistry. This thesis presents four projects investigating different aspects of pathogen destruction and biochemical sensing in a variety of systems, using the properties of p-phenylene ethynylenes (PEs), an especially flexible and well-studied class of conjugated molecules. Of particular relevance, some PEs are found to be effective dyes for amyloid …

The Effect Of Relative Electrode Size On The Performance Of A Supercapacitive Microbial Fuel Cell Design, Jeremiah Houghton

Nanoscience and Microsystems ETDs

Supercapacitive microbial fuel cells with various anode and cathode dimensions were investigated in order to determine the effect on capacitance and delivered power quality. The cathode size was determined to be the limiting component of the system, while anode size showed little effect on the devices performance. By doubling the cathode area, peak power output was improved by roughly 120% for a 10 ms pulse discharge. Doubling the cathode area also had a positive effect on the internal resistance of the cell, lowering the equivalent series resistance by approximately 47%. Doubling the anode area increased peak power output slightly, with …

Bio-Nano Interfaces: Enzyme Immobilization For Biomimetic Energy Harvesting, Rachel Hjelm

Nanoscience and Microsystems ETDs

In the face of todays rapidly growing energy demands accompanied by limited, non-renewable supplies, development of novel energy alternatives that are both renewable and inexpensive has become more important than ever. Development of 3D structures exploring the properties of nano-materials and biological molecules has been shown through the years as an effective path forward for the design of advanced bio-nano architectures for enzymatic fuel cells (EFCs). Despite advantages over conventional fuel cells, EFCs still suffer from several problems including low efficiency and stability. Overcoming these limitations in order to make them more viable for real world application is an ongoing …

Visualizing Mast Cell Activation: Single Molecule Dynamics Of Early Events In Fceri Signaling, Samantha Schwartz

Nanoscience and Microsystems ETDs

Healthy immune cell behavior requires sensitive and robust control over the processes that regulate signal transduction. In this work we employ single molecule fluorescence imaging techniques to quantify adapter protein recruitment, lateral mobility, receptor aggregation, and cytoskeletal organization to create a better understanding of many key processes in immune cell regulation. We focus on understanding the initiating events in FceRI signaling in mast cells. Mast cell signaling encompassing a wide array of cellular outcomes including calcium flux, release of pre-formed inflammatory mediators and the production of cytokines. Careful control over appropriate reactions to external antigens is necessary for mast cells …

Electrodeposition Of High Magnetostrictive Cobalt Iron Alloy Films For Smart Tags And Sensor Applications, Jamin Pillars

Nanoscience and Microsystems ETDs

Magnetostrictive CoFe films were investigated for use as magnetoelastic tags or sensors. The ability to electrodeposit these films enables batch fabrication processes to pattern a variety of geometries while controlling the film stoichiometry and crystallography. In current research looking at CoFe, improved magnetostriction was achieved using a co-sputtering, annealing, and quenching method1. Other current research has reported electrodeposited CoFe films using a sulfate based chemistry resulting in film compositions that are Fe rich in the range of Co0.3-0.4Fe0.7-0.6 and have problems of co-deposition of undesirables that can have a negative impact on magnetic properties2, 3. The research presented here focused …

Efficacy Of A Magnetic Drug Delivery System And Development Of An Orthotopic Lung Tumor Imaging Model, Amber Mcbride

Nanoscience and Microsystems ETDs

The aim of this work was the development of a novel drug delivery vehicle termed nano-in-microparticles (NIMs) to evaluate the magnetic-field dependent targeting of dry powder NIMs administered endotracheally using an ex vivo and in vivo rodent model. NIMs are a novel dry powder drug delivery vehicle containing 70% lactose (w/w), 20% SPIONs (w/w) and 10% fluorescent nanospheres (w/w). Mice were insufflated with NIMs delivery vehicle in the presence of magnetic field dependent targeting to the left ventral lung after thoracotomy; controls were insufflated with the NIMs in the absence of magnetic field dependent targeting. Quantification of deposition of the …