Nanoscience and Nanotechnology Commons^™

Interplay Of Molecular And Nanoscale Behaviors In Biological Soft Matter, Nicholas Ciaffone

Electronic Theses and Dissertations

The complexity of biological soft matter at the sub-micrometer level is fundamentally correlated to the functionalities at the larger scale. Reflecting the level of heterogeneities in the properties of systems remains challenging when probing small scales, due to the mismatch between the area surveyed with the tools offering nanoscale resolution, such as atomic force microscopy (AFM), and the scale of natural variations inherent to biology. Hence, to understand the physiological and mechanical alterations that occur within a single cell relative to a cell population, a multiscale approach is necessary. In this work we show that it is possible to observe …

Tunable Effect Of Metal Ions On Polyelectrolyte Mechanics, Angie Diaz

Electronic Theses and Dissertations

Polyelectrolyte based hydrogel fibers can mimic extracellular matrix and have applications such as drug delivery and tissue scaffolding. Metal ions play a critical role in hydrogel fiber stability via electrostatic interactions, but knowledge of how they modulate mechanical properties of individual polyelectrolyte polymers is lacking. In this study, electrospun polyacrylic acid with chitosan is used as a model system to evaluate ferric ion effect on nanofiber mechanics. Using dark field microscopy imaging and persistence length analysis, we demonstrate that ferric ions modulate the bending stiffness of nanofibers. Young's modulus of individual nanofibers is estimated at values of a few kilopascals, …

Size, Charge And Dose Dependent In-Vitro Kinetics Of Polystyrene Nanoparticles, Yasmine Abdellatif

Electronic Theses and Dissertations

The aim of the study described herein is to quantify the in-vitro kinetics of internalization of polystyrene nanoparticles (PS NPs) by cells. We used different charges, sizes and doses of fluorescently labelled PS NPs. Nanoparticles were characterized with UV-Vis, Fluorescence emission Dynamic Light Scattering (DLS) and Zeta potential for knowing their absorption, fluorescence spectra, size, charge, respectively. Additionally, cell viability was tested to know the toxicity of PS NPs. The quantitative uptake, the kinetics profile and rate of uptake were studied by using a new in-vitro fluorescence assay. This was achieved quantitatively and qualitatively by fluorescent plate reader and confocal …

Engineered Nanomaterials And Human Health: Part 1. Preparation, Functionalization And Characterization (Iupac Technical Report), Vladimir Gubala, Linda J. Johnston, Harald Friedrich Krug, Colin J. Moore, Christopher K. Ober, Michael Schwenk, Michel R. Vert

Reports

Research on engineered nanomaterials (ENM) has progressed rapidly from the very early stages of studying their unique, size-dependent physicochemical properties and commercial exploration to the development of products that influence our everyday lives. We have previously reviewed various methods for synthesis, surface functionalization, and analytical characterization of ENM in a publication titled 'Engineered Nanomaterials: Preparation, Functionalization and Characterization'. In this second, inter-linked document, we first provide an overview of important applications of ENM in products relevant to human healthcare and consumer goods, such as food, textiles, and cosmetics. We then highlight the challenges for the design and development of new …

Engineered Nanomaterials And Human Health: Part 2. Applications And Nanotoxicology (Iupac Technical Report) (Review), Vladimir Gubala, Linda J. Johnston, Harald Friedrich Krug, Colin J. Moore, Christopher K. Ober, Michael Schwenk, Michel R. Vert

Reports

Research on engineered nanomaterials (ENM) has progressed rapidly from the very early stages of studying their unique, size-dependent physicochemical properties and commercial exploration to the development of products that influence our everyday lives. We have previously reviewed various methods for synthesis, surface functionalization, and analytical characterization of ENM in a publication titled 'Engineered Nanomaterials: Preparation, Functionalization and Characterization'. In this second, inter-linked document, we first provide an overview of important applications of ENM in products relevant to human healthcare and consumer goods, such as food, textiles, and cosmetics. We then highlight the challenges for the design and development of new …

An Integrated Microstructural-Nanomechanical-Chemical Approach To Examine Material-Specific Characteristics Of Cementitious Interphase Regions, Mahdieh Khedmati, Yong-Rak Kim, Joseph A. Turner, Hani Alanazi, Charles Nguyen

Department of Mechanical and Materials Engineering: Faculty Publications

Effective properties and structural performance of cementitious mixtures are substantially governed by the quality of the interphase region because it acts as a bridge transferring forces between aggregates and a binding matrix and is generally susceptible to damage. As alternative binding agents like alkali-activated precursors have obtained substantial attention in recent years, there is a growing need for fundamental knowledge to uncover interphase formation mechanisms. In this paper, two different types of binding materials, i.e., fly ash-based geopolymer and ordinary portland cement, were mixed with limestone aggregate to examine and compare the microstructures and nanomechanical properties of interphase region. To …

Methods, Systems, And Devices For Surgical Access And Procedures, Shane M. Farritor, Mark Rentschler, Amy Lehman, Stephen R. Platt, Jeff Hawks

Department of Mechanical and Materials Engineering: Faculty Publications

The embodiments disclosed herein relate to various medical device components, including components that can be incorporated into robotic and/or in vivo medical devices. Certain embodiments include various actuation system embodiments, including fluid actuation systems, drive train actuation systems, and motorless actuation systems. Additional embodiments include a reversibly lockable tube that can provide access for a medical device to a patient's cavity and further provides a reversible rigidity or stability during operation of the device. Further embodiments include various operational components for medical devices, including medical device arm mechanisms that have both axial and rotational movement while maintaining a relatively compact …

Excess Charge-Carrier Induced Instability Of Hybrid Perovskites, Yuze Lin, Bo Chen, Yanjun Fang, Jingjing Zhao, Chunxiong Bao, Zhenhua Yu, Yehao Deng, Peter N. Rudd, Yanfa Yan, Yongbo Yuan, Jinsong Huang

Department of Mechanical and Materials Engineering: Faculty Publications

Identifying the origin of intrinsic instability for organic–inorganic halide perovskites (OIHPs) is crucial for their application in electronic devices, including solar cells, photodetectors, radiation detectors, and light-emitting diodes, as their efficiencies or sensitivities have already been demonstrated to be competitive with commercial available devices. Here we show that free charges in OIHPs, whether generated by incident light or by current-injection from electrodes, can reduce their stability, while efficient charge extraction effectively stabilizes the perovskite materials. The excess of both holes and electrons reduce the activation energy for ion migration within OIHPs, accelerating the degradation of OIHPs, while the excess holes …

Visible Light Crosslinkable Human Hair Keratin Hydrogels, Kan Yue, Yanhui Liu, Batzaya Byambaa, Vaishali Singh, Wanjun Liu, Xiuyu Li, Yunxia Sun, Yu Shrike Zhang, Ali Tamayol, Peihua Zhang, Kee Woei Ng, Nasim Annabi, Ali Khademhosseini

Department of Mechanical and Materials Engineering: Faculty Publications

Keratins extracted from human hair have emerged as a promising biomaterial for various biomedical applications, partly due to their wide availability, low cost, minimal immune response, and the potential to engineer autologous tissue constructs. However, the fabrication of keratin-based scaffolds typically relies on limited crosslinking mechanisms, such as via physical interactions or disulfide bond formation, which are time-consuming and result in relatively poor mechanical strength and stability. Here, we report the preparation of photocrosslinkable keratin-polyethylene glycol (PEG) hydrogels via the thiol-norbornene “click” reaction, which can be formed within one minute upon irradiation of visible light. The resulting keratin-PEG hydrogels showed …

Hydrophobic Surface Modification Of Polymethyl Methacrylate By Two-Dimensional Plasma Jet Array At Atmospheric Pressure, Feng Liu, Meiling Cai, Bo Zhang, Zhi Fang, Chunqi Jiang, Kostya Ken Ostrikov

Bioelectrics Publications

Recently developed atmospheric pressure plasma jet (APPJ) is considered as a novel and efficient technique for uneven surfaces processing and APPJ array effectively expands the treatment area of a single APPJ. In this paper, a two-dimensional (2D) APPJ array in Ar/tetramethylsilane (TMS) is used to improve the surface hydrophobicity of polymethyl methacrylate (PMMA) by depositing polymerized silicalike clusters on the jet-PMMA interface. The electrical and optical characteristics of the 2D Ar/TMS APPJ array are measured to optimize experimental conditions. The wettability of jet-PMMA interface is assessed by measuring water contact angle, which increases from 65° to a maximum value of …

Methods, Systems, And Devices Relating To Force Control Surgical Systems, Shane M. Farritor, Thomas Frederick, Kearney Lackas, Joe Bartels, Jacob Greenburg

Department of Mechanical and Materials Engineering: Faculty Publications

The various embodiments herein relate to robotic surgical systems and devices that use force and/or torque sensors to measure forces applied at various components of the system or device. Certain implementations include robotic surgical devices having one or more force/torque sensors that detect or measure one or more forces applied at or on one or more arms. Other embodiments relate to systems having a robotic surgical device that has one or more sensors and an external controller that has one or more motors such that the sensors transmit information that is used at the controller to actuate the motors to …

Frequency Dependent Deformation Reversibility During Cyclic Loading, Shuai Shao, Michael M. Khonsari, Jian Wang, Nima Shamsaei, Nan Li

Department of Mechanical and Materials Engineering: Faculty Publications

High-frequency testing (HFT) is useful for accelerated fatigue testing of conventional materials that typically serve under low-frequency loading conditions, as well as for the assessment of the robustness of microelectromechanical systems which typically experience high-frequency service conditions. Using discrete dislocation dynamics, we attempt to elucidate the effect of loading frequency on the reversibility of cyclic deformation. We demonstrate that the HFT induces a higher fraction of reversible cyclic deformation because of a larger portion of elastic/anelastic deformation due to limited dislocation mobility, and a higher degree of reversibility in plastic deformation owing to the less occurrence of cross-slip.

An Integrated Microstructural-Nanomechanical-Chemical Approach To Examine Material-Specific Characteristics Of Cementitious Interphase Regions, Mahdieh Khedmati, Yong-Rak Kim, Joesph A. Turner, Hani Alanazi, Charles Nguyen

Department of Mechanical and Materials Engineering: Faculty Publications

Effective properties and structural performance of cementitious mixtures are substantially governed by the quality of the interphase region because it acts as a bridge transferring forces between aggregates and a binding matrix and is generally susceptible to damage. As alternative binding agents like alkali-activated precursors have obtained substantial attention in recent years, there is a growing need for fundamental knowledge to uncover interphase formation mechanisms. In this paper, two different types of binding materials, i.e., fly ash-based geopolymer and ordinary portland cement, were mixed with limestone aggregate to examine and compare the microstructures and nanomechanical properties of interphase region. To …

Neuroprotective And Anti-Inflammatory Effects Of Rhus Coriaria Extract In A Mouse Model Of Ischemic Optic Neuropathy, Saba Khalilpour, Ghazaleh Behnammanesh, Fouad Suede, Mohammed O. Ezzat, Jayadhisan Muniandy, Yasser Tabana, Mohamed B. K. Ahamed, Ali Tamayol, Amin Malik Shah Majid, Enrico Sangiovanni, Mario Dell'agli, Aman Shah Majid

Department of Mechanical and Materials Engineering: Faculty Publications

Modulating oxidative stresses and inflammation can potentially prevent or alleviate the pathological conditions of diseases associated with the nervous system, including ischemic optic neuropathy. In this study we evaluated the anti-neuroinflammatory and neuroprotective activities of Rhus coriaria (R. coriaria) extract in vivo. The half maximal inhibitory concentration (IC₅₀) for DPPH, ABTS and B-carotene were 6.79 ± 0.009 µg/mL, 10.94 ± 0.09 µg/mL, and 6.25 ± 0.06 µg/mL, respectively. Retinal ischemia was induced by optic nerve crush injury in albino Balb/c mice. The anti-inflammatory activity of ethanolic extract of R. coriaria (ERC) and linoleic acid (LA) on …

Molecular Doping Enabled Scalable Blading Of Efficient Hole-Transport-Layer-Free Perovskite Solar Cells, Wu-Qiang Wu, Qi Wang, Yanjun Fang, Yuchuan Shao, Shi Tang, Yehao Deng, Haidong Lu, Ye Liu, Tao Li, Zhibin Yang, Alexei Gruverman, Jinsong Huang

Department of Mechanical and Materials Engineering: Faculty Publications

The efficiencies of perovskite solar cells (PSCs) are now reaching such consistently high levels that scalable manufacturing at low cost is becoming critical. However, this remains challenging due to the expensive hole-transporting materials usually employed, and difficulties associated with the scalable deposition of other functional layers. By simplifying the device architecture, hole-transport-layer-free PSCs with improved photovoltaic performance are fabricated via a scalable doctor-blading process. Molecular doping of halide perovskite films improved the conductivity of the films and their electronic contact with the conductive substrate, resulting in a reduced series resistance. It facilitates the extraction of photoexcited holes from perovskite directly …

Photonic Grating Coupler Designs For Optical Benching, Eng Wen Ong

Legacy Theses & Dissertations (2009 - 2024)

Background: Silicon Photonics has been rapidly developing as a field. The primary reason for this is its lower operating costs and faster switching rates for use in big data centres. Instead of microns-wide copper lines to transmit signals, silicon photonic chips use waveguides, usually of silicon or silicon nitride. Photonic signals bypass the issues of resistive-capacitance lag (RC-lag) and resistive-heating encountered by copper lines. Additionally, a single waveguide may transmit multiple signals along different carrier wavelengths.

Economics Of R&D Specialization In The Semiconductor Industry, Kyun Kim

Legacy Theses & Dissertations (2009 - 2024)

Starting in the 1970s, specialized suppliers have entered the semiconductor industry to supply capital equipment, or tools, used in semiconductor manufacturing to downstream semiconductor companies. After the entry of these external suppliers, semiconductor chip producers began to rely in varying degrees on them for the R&D to improve the quality of capital equipment, while they themselves began to focus on design and production of chips. In my dissertation, I conduct an empirical and theoretical investigation to support my hypothesis that the difference in R&D incentives between the upstream suppliers and downstream chip manufacturers was the important reason for the emergence …

Investigation Of The Ms2 Bacteriophage Capsid As An Mri-Capable, Brain-Targeted Nanoparticle Platform, Stephanie M. Curley

Legacy Theses & Dissertations (2009 - 2024)

Novel methods are needed to traverse the blood-brain barrier (BBB) and deliver drugs to specific targets in the brain. To this end, MS2 bacteriophage was explored as a multifunctional transport and targeting vector. The MS2 capsid exterior was modified with two different targeting moieties for delivery across the BBB and targeting specific regions of interest in the brain. Successful modification of MS2 capsids with a brain targeting peptide and NMDAR2D-targeting antibody was confirmed by immunoblotting and fluorescence detection. To measure transport efficiency of MS2 particles across an in vitro BBB model, a highly sensitive RT-qPCR protocol was developed and implemented. …

The Microfluidic Intravital Window : A Tool For Manipulation And Imaging Of The Tumor Microenvironment, Logan William Butt

Legacy Theses & Dissertations (2009 - 2024)

The tumor microenvironment (TME) is a heterogeneous collection of both healthy and pathological cells, whose complex interactions hold the key for understanding and overcoming cancer. Metastasis leverages these complex interactions into a sophisticated process by which single cells from the tumor disseminate into the blood and form new colonies in other organ systems. Subsequent formation of tumors throughout the body, as a direct result of metastatic events, is responsible for most deaths related to cancer, making metastasis a necessary target for cancer therapy.

Growth Of Epitaxial Graphene On Single Crystal Copper Surfaces By Chemical Vapor Deposition, Tyler Rutley Mowll

Legacy Theses & Dissertations (2009 - 2024)

Graphene is of significant interest due to its unique properties, such as high carrier mobility, mechanical strength, and thermal conductivity. Potential applications include next generation transistors, interconnects, biological and chemical sensing devices, and super capacitors. The research presented here addresses unresolved questions regarding the nucleation and growth of graphene by chemical vapor deposition (CVD) on the high index surfaces of copper single crystals. While much CVD graphene growth has been performed on copper foils, the polycrystalline nature of the foils renders large-scale single domain growth of graphene difficult. For this reason, many groups seek to reduce the nucleation rate of …

Impact Of Spiro Ammonium Electrolytes On Electric Double Layer Capacitors, Donald Derosa

Legacy Theses & Dissertations (2009 - 2024)

Electric Double Layer Capacitors (EDLC) are high power (103 W kg-1), durable (>500,000 cycles) energy storage devices that are promising candidates for Hybrid Energy Storage Systems (HESS) , automotive and smart grid applications. EDLCs when coupled with lithium ion batteries in HESS configurations for hybrid vehicles have been shown to reduce capacity related degradation by a factor of 2 and impedance related degradation by 5.9. Despite these promising advantages, the adoption of EDLCs has been hampered due to concerns regarding the low volumetric and gravimetric energy density of these devices. Researchers have attempted to address these concerns through the …

Zno Nanowires For Advanced X-Ray Source Applications, Vance Scott Robinson

Legacy Theses & Dissertations (2009 - 2024)

X-ray system technology trends tend towards simpler, smaller and more efficient devices. A broad range of applications are driving contemporary efforts in X-ray source miniaturization: Portable and/or remote nondestructive evaluation; High throughput protein crystallography, invasive radiotherapy; monitoring fluid flow and particulate generation in situ; and portable radiography devices for battle-front or large scale disaster triage scenarios. Most of the x-ray sources for these applications follow a top-down approach focused on improving portability, and reducing mass and/or size.

Design Of Dna Strand Displacement Based Circuits, Aby Konampurath George

Wayne State University Dissertations

DNA is the basic building block of any living organism. DNA is considered a popular candidate for future biological devices and circuits for solving genetic disorders and several other medical problems. With this objective in mind, this research aims at developing novel approaches for the design of DNA based circuits. There are many recent developments in the medical field such as the development of biological nanorobots, SMART drugs, and CRISPR-Cas9 technologies. There is a strong need for circuits that can work with these technologies and devices. DNA is considered a suitable candidate for designing such circuits because of the programmability …

Exploring The Effects Of Zinc Nanoparticle Concentration, Antioxidant, And Media On Cilantro (Coriandrum Sativum), And Radish (Raphanus Sativus) Plants Growth, Venkata Laxma Reddy Pullagurala

Open Access Theses & Dissertations

Engineered nanomaterials (ENMs) have proven to be one of the emerging chemicals of concern in the contemporary times. Soil acts as one of the major sinks of these ENMs. Reports have shown that ENMs have varied effects on soil biota. Particularly, their effects on plants are inconsistent. Amongst these ENMs, ZnO nanoparticles (nZnO) are the fourth largest raw materials in the nanotechnology industry. Globally, it is estimated that around 34,000 tons of n ZnO are utilized per year. The nZnO exposure on terrestrial plants yielded both beneficial as well as detrimental effects. Recently, there is an emerging evidence about the …

Effects Of Unweathered Or Soil Weathered Copper-Based Nanoparticles And Compounds On Soil Grown Bell Pepper (Capsicum Annuum) And Spinach (Spinacia Oleracea) Plants, Swati Rawat

Open Access Theses & Dissertations

Engineered nanoparticles (ENPs) find large scale industrial application because of their promising chemical, physical, electrical, magnetic, optical, and electronic properties. Copper-based ENP are used as gas sensors, in catalysts, electronics, semi-conductors, and in agriculture. They have been useful as agricultural amendments in the form of pesticides, herbicides, and fertilizers because of their antifungal and antibacterial properties. They also find application in electronics and sensors used in precision agriculture. Due to their massive production and use, ENPs are likely to be ubiquitous in the environment around us in the near future. Application of biosolids for fertilization and water from wastewater treatment …

Surface And Structural Modification Of Carbon Electrodes For Electroanalysis And Electrochemical Conversion, Yan Zhang

Theses and Dissertations--Chemistry

Electrocatalysis is key to both sensitive electrochemical sensing and efficient electrochemical energy conversion. Despite high catalytic activity, traditional metal catalysts have poor stability, low selectivity, and high cost. Metal-free, carbon-based materials are emerging as alternatives to metal-based catalysts because of their attractive features including natural abundance, environmental friendliness, high electrical conductivity, and large surface area. Altering surface functionalities and heteroatom doping are effective ways to promote catalytic performance of carbon-based catalysts. The first chapter of this dissertation focuses on developing electrode modification methods for electrochemical sensing of biomolecules. After electrochemical pretreatment, glassy carbon demonstrates impressive figures-of-merit in detecting small, redox-active …

Thermal Stability Characterization Of Tunneling Magneto Resistive Structure For Data Storage Applications, Pornchai Rakpongsiri

Chulalongkorn University Theses and Dissertations (Chula ETD)

The conventional read sensor technology used in hard disk drives is the tunneling magneto resistive (TMR) device. The revolutions of technology have been developed to achieve high performance of reading signal resulting in very thin and complicated device layers which thermal induced degradation and defects would be concerned. In this research, a thermal stress has been applied to TMR devices between 150-250 ℃ for reliability investigation. The resistance, amplitude and asymmetry parameters, before and after the thermal stress, were measured using a quasi-static tester (QST). The results showed the temperature dependence of the percentage change in QST resistance, asymmetry and …

Cavitons And Spontaneous Hot Flow Anomalies In A Hybrid-Vlasov Global Magnetospheric Simulation, Xochitl Blanco-Cano, Markus Battarbee, Lucile Turc, Andrew P. Dimmock, Emilia K.J. Kilpua, Sanni Hoilijoki, Urs Ganse, David G. Sibeck, Paul A. Cassak, Robert C. Fear, Riku Jarvinen, Liisa Juusola, Yann Pfau-Kempf, Rami Vainio, Minna Palmroth

Faculty & Staff Scholarship

Abstract. In this paper we present the first identification of foreshock cavitons and the formation of spontaneous hot flow anomalies (SHFAs) with the Vlasiator global magne- tospheric hybrid-Vlasov simulation code. In agreement with previous studies we show that cavitons evolve into SHFAs. In the presented run, this occurs very near the bow shock. We report on SHFAs surviving the shock crossing into the down- stream region and show that the interaction of SHFAs with the bow shock can lead to the formation of a magnetosheath cavity, previously identified in observations and simulations. We report on the first identification of long-term …

Magnetic And Catalytic Properties Of Transition Metal Doped Mos2 Nanocrystals, Luis Martinez

Open Access Theses & Dissertations

Magnetism and catalytic activity of nanoscale layered two-dimensional (2D) transition metal dichalcogenides (TMDs) have gained an increasing research interest in the recent past. To broaden the current knowledge and understanding on this subject, in this work, together with my collaborators, I study the magnetic and electrocatalytic properties of hydrothermally grown pristine and transition metal doped (10% of Co, Ni, Fe and Mn) 2H-MoS2 nanosheets/nanocrystals (NCs), with the particle size of 25-30 nm. A broad range of experimental measurements such as x-ray diffraction, transmission electron microscopy, x-ray photo absorption spectroscopy, Raman spectroscopy, magnetic, catalytic and electron spin resonance have been employed …

Carbazole Based Multifunctional Dopamine Agonists And Related Molecules As Potential Symptomatic And Disease Modifying Therapeutic Agents For Parkinson’S Disease, Asma S.Mohamed Elmabruk

Wayne State University Dissertations

Parkinson’s disease (PD) is a progressive neurodegenerative disease that develops from gradual depletion of dopamine (DA) and dopaminergic neurons in the substantia nigra pars compacta (SNc) with the accumulation of intraneuronal proteinaceous matter named as Lewy bodies. The four cardinal symptoms associated with PD are tremor, rigidity, bradykinesia, and postural instability. Although the exact mechanism and etiology of PD are not fully understood, several factors have been implicated in the pathogenesis and progression of PD including protein aggregation, oxidative stress, mitochondrial dysfunction, environmental, and genetic factors.

The current therapy of Parkinson’s disease is categorized into four classes: levodopa, DA agonists, …