Nanoscience and Nanotechnology Commons^™

Lab-On-A-Chip Nucleic-Acid Analysis Towards Point-Of-Care Applications, Varun Lingaiah Kopparthy

Doctoral Dissertations

Recent infectious disease outbreaks, such as Ebola in 2013, highlight the need for fast and accurate diagnostic tools to combat the global spread of the disease. Detection and identification of the disease-causing viruses and bacteria at the genetic level is required for accurate diagnosis of the disease. Nucleic acid analysis systems have shown promise in identifying diseases such as HIV, anthrax, and Ebola in the past. Conventional nucleic acid analysis systems are still time consuming, and are not suitable for point-ofcare applications. Miniaturized nucleic acid systems has shown great promise for rapid analysis, but they have not been commercialized due …

Potential Applications For Halloysite Nanotubes Based Drug Delivery Systems, Lin Sun

Doctoral Dissertations

Drug delivery refers to approaches, formulations, technologies, and systems for transporting a drug in the body. The purpose is to enhance the drug efficacy and to reduce side reactions, which can significantly improve treatment outcomes. Halloysite is a naturally occurred alumino-silicate clay with a tubular structure. It is a biocompatible material with a big surface area which can be used for attachment of targeted molecules. Besides, loaded molecules can present a sustained release manner in solution. These properties make halloysite nanotubes (HNTs) a good option for drug delivery.

In this study, a drug delivery system was built based on halloysite …

Fabrication And Characterization Of Conductive Melt Electrospun Fibers, Brandon Ross

Graduate Theses & Non-Theses

Conductive polymer nanocomposites are a type of particle reinforced plastic composite where the doping material is electrically conductive. The diverse properties of an engineered composite material allow for the material properties to be fine-tuned for the specific application. This research focuses on using carbon allotropes, such as two-dimensional graphene and one-dimensional carbon nanotubes, to achieve direct current electrical conductivity through a polymer fiber. Melt electrospinning is the process used for creating the micrometer scale fibers by melting thermoplastic materials. High electrostatic fields apply a force to the polymer melt and a single fiber is drawn out. The resistivity of the …

An Examination Of The Indentation Size Effect In Fcc Metals And Alloys From A Kinetics Based Perspective Using Nanoindentation, David Earl Stegall

Mechanical & Aerospace Engineering Theses & Dissertations

The indentation size effect (ISE) in metals is described as the rise in hardness with decreasing depth of indentation and contradicts conventional plasticity behavior. The goal of this dissertation is to further examine the fundamental dislocation mechanisms that may be contributing to the so-called indentation size effect. In this work, we examined several metals and alloys including 99.999% Aluminum (SFE ~200 mJ/m²), 99.95% Nickel (SFE ~125 mJ/m²), 99.95% Silver (SFE ~22 mJ/m²⁾, and three alloys, alpha brass 70/30 (SFE >10 mJ/m²), 70/30 nickel copper (SFE ~100 mJ/ …

Thermal Analysis Of Continuous And Patterned Multilayer Films In The Presence Of A Nanoscale Hot Spot, Jia-Yang Juang, Jinglin Zheng

Department of Mechanical and Materials Engineering: Faculty Publications

Thermal responses of multilayer films play essential roles in state-of-the-art electronic systems, such as photo/micro-electronic devices, data storage systems, and silicon-on-insulator transistors. In this paper, we focus on the thermal aspects of multilayer films in the presence of a nanoscale hot spot induced by near field laser heating. The problem is set up in the scenario of heat assisted magnetic recording (HAMR), the next-generation technology to overcome the data storage density limit imposed by superparamagnetism. We characterized thermal responses of both continuous and patterned multilayer media films using transient thermal modeling. We observed that material configurations, in particular, the thermal …

Case Study Of Quantifying Energy Loss Through Ceiling-Attic Recessed Lighting Fixtures Through 3d Numerical Simulation, Ri Na, Shengmao Lin, Zhigang Shen, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

Abstract Air leakage through recessed lighting fixtures has been identified as a common issue that causes extra energy consumption in residential buildings. However, few quantitative studies in this area were found. As such, a preliminary assessment of the magnitude of this type of energy loss was conducted by using three-dimensional (3D) transient computational fluid dynamics (CFD) models. A hypothetical layout of recessed lighting fixtures was designed with boundary conditions of four different seasons, which were obtained from recorded roof/attic temperature data sets. The results of the study indicate that leakage of recessed lighting fixtures could be a significant channel of …

Fabrication Of Nano Patterned Arrays And Optical Applications, Aktaruzzaman Al-Hossain

Student Theses and Dissertations

Most of the researches in developing arrayed patterns have utilized the lithography process with pre-patterned structures. However, lithography itself is considerably low efficient in terms of cost and time, especially by the chemical etching process. Furthermore, the chemical etching process is also a potential barrier in three dimensional structures with multi-layered patterns. The limitation of substrate and mask size is also disadvantageous to the larger area in real-time fabrication process. In this study, a new approach using the solid thin-film dewetting process with intense pulsed light annealing and optical study towards wavelength transformation is introduced to overcome the addressed problems. …

Compositionally Graded Bulk Heterojunction Devices And Methods Of Manufacturing The Same, Jinsong Huang, Zhengguo Xiao

Department of Mechanical and Materials Engineering: Faculty Publications

Systems and methods are described to form compositionally graded BHJ structures utilizing solvent-fluxing techniques. In implementations, the systems and methods described herein involve a high boiling point additive, a solution of a polymer donor and an acceptor, a substrate material, a working solvent, and a flux solvent for formation of compositionally graded BHJ structures.

Local Writing Of Exchange Biased Domains In A Heterostructure Of Co/Pd Pinned By Magnetoelectric Chromia, Uday Singh, William Echtenkamp, M. Street, Christian Binek, Shireen Adenwalla

Shireen Adenwalla Papers

The writing of micrometer-scaled exchange bias domains by local, laser heating of a thin-film heterostructure consisting of a perpendicular anisotropic ferromagnetic Co/Pd multilayer and a (0001) oriented film of the magnetoelectric antiferromagnet Cr₂O₃ (chromia) is reported. Exchange coupling between chromia’s boundary magnetization and the ferromagnet leads to perpendicular exchange bias. Focused scanning magneto-optical Kerr measurements are used to measure local hysteresis loops and create a map of the exchange bias distribution as a function of the local boundary magnetization imprinted in the antiferromagnetic pinning layer on field cooling. The robust boundary magnetization of the Cr₂O …

Bioink Properties Before, During And After 3d Bioprinting, Katja Hölzl, Shengmao Lin, Liesbeth Tytgat, Sandra Van Vlierberghe, Linxia Gu, Aleksandr Ovsianikov

Department of Mechanical and Materials Engineering: Faculty Publications

Bioprinting is a process based on additive manufacturing from materials containing living cells. These materials, often referred to as bioink, are based on cytocompatible hydrogel precursor formulations, which gel in a manner compatible with different bioprinting approaches. The bioink properties before, during and after gelation are essential for its printability, comprising such features as achievable structural resolution, shape fidelity and cell survival. However, it is the final properties of the matured bioprinted tissue construct that are crucial for the end application. During tissue formation these properties are influenced by the amount of cells present in the construct, their proliferation, migration …

Optical Patterning Of Trapped Charge In Nitrogen-Doped Diamond, Harishankar Jayakumar, Jacob Henshaw, Siddharth Dhomkar, Daniela Pagliero, Abdelghani Laraoui, Neil B. Manson, Remus Albu, Marcus W. Doherty, Carlos A. Meriles

Department of Mechanical and Materials Engineering: Faculty Publications

The nitrogen-vacancy (NV) centre in diamond is emerging as a promising platform for solid-state quantum information processing and nanoscale metrology. Of interest in these applications is the manipulation of the NV charge, which can be attained by optical excitation. Here, we use two-colour optical microscopy to investigate the dynamics of NV photo-ionization, charge diffusion and trapping in type-1b diamond. We combine fixed-point laser excitation and scanning fluorescence imaging to locally alter the concentration of negatively charged NVs, and to subsequently probe the corresponding redistribution of charge. We uncover the formation of spatial patterns of trapped charge, which we qualitatively reproduce …

Preparations And Photoelectrochemical Properties Of Phosphate Modified Rgo-Biobr Nanocomposites, Shuang-Ying Chen, Zhi-Jun Li, Xu-Liang Zhang, Kang Hu, Rui Yan, Li-Qiang Jing

Journal of Electrochemistry

The RGO-BiOBr nanocomposites have been successfully synthesized by a hydrothermal process, and then modified with phosphorous acids. The photoelectrochemical properties of the fabricated RGO-BiOBr nanocomposite films were studied. The results indicate that the photocurrent densities of RGO-BiOBr were much larger compared with those of the bare BiOBr, and interestingly, the photocurrent densities were further improved after phosphate modification. Based on the analyses of the produced hydroxyl radical amounts, the enhanced photocurrent densities could be attributed to the introduction of RGO and to the formed negative fields of modified phosphate groups, which are favorable for electrons to be transferred and for …

Activation Effect Of Nano-Carbon Derived From Co2 On Lead Electrode In Sulfuric Aqueous Solution, Yu-Qiao Song, Hua Zhu, Guang-Jin Zhao, Wen-Long Wu, Shou-Bin Zhou, Di-Hua Wang

Journal of Electrochemistry

Serious sulfation of the negative plate is one of the most popular reasons of the early failure of lead-acid battery. Addition of nano-carbon was proved to be effective for recovering the sulfated electrode and the property of the carbon material always plays an important role. In this work, a new kind of nano-carbon material with high electrical conductivity and good adsorption capability for heavy metal cations, which is electrochemically prepared from CO₂ in molten carbonates, was tested as activation additive for the sulfated lead electrode by cyclic voltammetry and SEM measurements. The results showed that the as-prepared carbon can …

WoX/Pedot:Pss Double-Layered Hole-Transport Layers For Efficient And Stable Planar Heterojunction Perovskite Solar Cells, Wen-Yuan Qiao, Qiang Guo, Cong Li, Shuang Ma, Fu-Zhi Wang, Song-Yuan Dai, Zhan-Ao Tan

Journal of Electrochemistry

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is a commonly used hole-transport material in the perovskite solar cells (PerSCs) structure of perovskite/fullerene planer heterojunction, but it also has a negative effect on the stability of device because of its acidity which will corrode metal oxide transparent electrodes. In this work, a WO_x hole-transport layer with high work function was inserted into the PEDOT: PSS and FTO to enhance the stability and photovoltaic performance. The inserted WO_x layer not only can avoid direct contact between PEDOT:PSS and FTO, but also can further reduce the contact barrier between the electrode interface. We studied the effect …

Development And Evaluation Of A Near-Infrared (1047 Nm) Photoacoustic-Nephelometer Spectrometer For Detection And Optical Characterization Of Black Carbon Aerosol, Yang Yu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Black carbon (BC) aerosol are aggregates of small carbon spherules of <10 nm to approximately 50 nm in diameter. They are characterized by their strong visible light absorption property with a mass absorption cross-section (MAC) value above 5 m² g ⁻¹ at a wavelength λ = 550 nm, which increases inversely with wavelengths from near-infrared (≈1 µm) to ultraviolet with a power law of one. The absorbing nature of BC aerosol has been implicated in regional atmospheric warming, changing of monsoon patterns, and accelerated melting of the glaciers. The BC radiative effects over earth is currently estimated within a factor of four, resulting in one of the largest uncertainties in climate modeling. This uncertainty results from our inadequate knowledge about regional BC emission rates, and associated aerosol …

Generalizing The Quantum Dot Lab Towards Arbitrary Shapes And Compositions, Matthew A. Bliss, Prasad Sarangapani, James Fonseca, Gerhard Klimeck

The Summer Undergraduate Research Fellowship (SURF) Symposium

As applications in nanotechnology reach the scale of countable atoms, computer simulation has become a necessity in the understanding of new devices, such as quantum dots. To understand the various optoelectronic properties of these nanoparticles, the Quantum Dot Lab (QDL) has been created and powered by NEMO5 to simulate on multi-scale, multi-physics bases. QDL is easy to use by offering choices of different QD geometries such as shapes and sizes to the users from a predefined menu. The simplicity of use, however, limits the simulation of general QD shapes and compositions. A method to import generic strained crystalline and amorphous …

Modeling Of A Roll-To-Roll Plasma Cvd System For Graphene, Yudong Chen, Majed A. Alrefae, Anurag Kumar, Timothy S. Fisher

The Summer Undergraduate Research Fellowship (SURF) Symposium

Graphene is a 2D carbon material that has extraordinary physical properties relevant to many industrial applications such as electronics, oxidation barrier and biosensors. Roll-to-roll plasma chemical vapor deposition (CVD) has been developed to manufacture graphene at large scale. In a plasma CVD chamber, graphene is grown on a copper foil as it passes through a high-temperature plasma region. The temperatures of the gas and the copper foil play important roles in the growth of graphene. Consequently, there is a need to understand the temperature and gas velocity distributions in the system. The heat generated in the plasma creates a thermal …

Development Of Micro-/Nano-Architectures For Intracellular Sensing Platform, Ryan M. Preston, Dae Seung Wie, Chi Hwan Lee

The Summer Undergraduate Research Fellowship (SURF) Symposium

Currently available nanotechnologies are capable of creating various nanostructures in controlled dimensions such as particles (0D), wires (1D), membranes (2D), and cubes (3D) by exploiting “top-down” or “bottom-up” methods. However, there exist limitations to systematically construct hierarchical nanostructures with geometric complexities. This study is focused on developing a novel nanofabrication strategy that can rationally produce a set of hierarchical nanostructures configured with precisely engineered facets, tip shapes, and tectonic motifs. We aim to identify a collection of optimal materials, array layouts, basic components, and nanofabrication techniques for the production of hierarchical nanostructures by exploiting device-grade semiconducting silicon materials. To accomplish …

Temperature Dependent Surface Modification Of Tungsten Exposed To High-Flux Low-Energy Helium Ion Irradiation, Antony Q. Damico, Jitendra K. Tripathi, Theodore J. Novakowski, Gennady Miloshevsky, Ahmed Hassanein

The Summer Undergraduate Research Fellowship (SURF) Symposium

Nuclear fusion is a great potential energy source that can provide a relatively safe and clean limitless supply of energy using hydrogen isotopes as fuel material. ITER (international thermonuclear experimental reactor) is the world first fusion reactor currently being built in France. Tungsten (W) is a prime candidate material as plasma facing component (PFC) due to its excellent mechanical properties, high melting point, and low erosion rate. However, W undergoes a severe surface morphology change when exposed to helium ion (He⁺) bombardment under fusion conditions. It forms nanoscopic fiber-form structures, i.e., fuzz on the surface. Fuzz is brittle …

Quantum Dot Lab : Incorporation Of Alloys In The Capping Layer Of Multi-Layer Quantum Dot, Unmesha U. Kale, Prasad Sarangapani, Jim Fonseca, Gerhard Klimeck

The Summer Undergraduate Research Fellowship (SURF) Symposium

Quantum dots have enhanced the performance of several optoelectronic devices. Designing and obtaining optimal quantum dot structures requires intensive simulation. Quantum Dot Lab on nanoHUB provides such a simulation platform. The simulation is fully parallelized and depending on the structure, the tool decides the computational resource which is to be used for the simulation. To obtain accurate predictions of quantum dot structures it is essential to provide a variety of simulation parameters to the user. In this research, a user interface was created where the user can simulate alloys by Random distribution and by Virtual Crystal Approximation(VCA) type distribution in …