Open Access. Powered by Scholars. Published by Universities.®

Nanotechnology Fabrication Commons

Open Access. Powered by Scholars. Published by Universities.®

388 Full-Text Articles 686 Authors 97,436 Downloads 47 Institutions

All Articles in Nanotechnology Fabrication

Faceted Search

388 full-text articles. Page 1 of 18.

Development And Test Of High Temperature Surface Acoustic Wave Gas Sensors, Armando E. Ayes Moncada 2020 University of Maine

Development And Test Of High Temperature Surface Acoustic Wave Gas Sensors, Armando E. Ayes Moncada

Electronic Theses and Dissertations

The demand for sensors in hostile environments, such as power plant environments, exhaust systems and high-temperature metallurgy environments, has risen over the past decades in a continuous attempt to increase process control, improve energy and process efficiency in production, reduce operational and maintenance costs, increase safety, and perform condition-based maintenance in equipment and structures operating in high-temperature, harsh-environment conditions. The increased reliability, improved performance, and development of new sensors and networks with a multitude of components, especially wireless networks, are the target for operation in harsh environments. Gas sensors, in particular hydrogen gas sensors, operating above 200°C are required ...


Design Of Submicron Structured Guided-Mode-Resonance Near-Infrared Polarizer, Marzia Zaman 2020 University of Arkansas, Fayetteville

Design Of Submicron Structured Guided-Mode-Resonance Near-Infrared Polarizer, Marzia Zaman

Theses and Dissertations

The objective of this research is to design a larger submicron linear polarizer in the near-infrared wavelength range with a wide bandwidth which can be fabricated using the conventional thin-film microfabrication technology to reduce cost. For this purpose, a gold (Au) wire-grid transmission-type transverse-magnetic (TM) polarizer and a silicon (Si) wire-grid reflection-type TM polarizer, were designed using the guided-mode-resonance filter. The Au wire-grid TM polarizer of 700nm grating width and 1200nm grating period has 95% transmittance at 2400nm, more than 1000nm resonance peak bandwidth, and an extinction ratio (ER) of around 300 with a moderated level of sidebands. The 700nm ...


Cdse Quantum Dots Synthesis Laboratory Course For High School Students, Danlin Zuo, Gyuseok Kim, David Jones 2019 Singh Center for Nanotechnology

Cdse Quantum Dots Synthesis Laboratory Course For High School Students, Danlin Zuo, Gyuseok Kim, David Jones

Protocols and Reports

Cadmium selenide quantum dot is a fascinating subject for leading high school students to the quantum world. An 8-hour laboratory course for up to 12 high school students is proposed. The 8-hour course consist of two 4-hours sections. This laboratory course includes the quantum dot syntheses, absorption and emission characterization, and data analysis. The proposes process runs at relatively lower temperature which means safe and easy, and shows apparent experimental results.


Interfacial Contact With Noble Metal - Noble Metal And Noble Metal - 2d Semiconductor Nanostructures Enhance Optical Activity, Ricardo Raphael Lopez Romo 2019 University of Arkansas, Fayetteville

Interfacial Contact With Noble Metal - Noble Metal And Noble Metal - 2d Semiconductor Nanostructures Enhance Optical Activity, Ricardo Raphael Lopez Romo

Theses and Dissertations

Noble metal nanoparticles and two-dimensional (2D) transition metal dichalcogenide (TMD) crystals offer unique optical and electronic properties that include strong exciton binding, spin-orbital coupling, and localized surface plasmon resonance. Controlling these properties at high spatiotemporal resolution can support emerging optoelectronic coupling and enhanced optical features. Excitation dynamics of these optical properties on physicochemically bonded mono- and few-layer TMD crystals with metal nanocrystals and two overlapping spherical metal nanocrystals were examined by concurrently (i) DDA simulations and (ii) far-field optical transmission UV-vis spectroscopic measurements. Initially, a novel and scalable method to unsettle van der Waals bonds in bulk TMDs to prepare ...


Exploring Convergence Of Snake Skin-Inspired Texture Designs And Additive Manufacturing For Mechanical Traction, Catherine Sue Tiner 2019 University of Arkansas, Fayetteville

Exploring Convergence Of Snake Skin-Inspired Texture Designs And Additive Manufacturing For Mechanical Traction, Catherine Sue Tiner

Theses and Dissertations

This research focuses on the understanding, development, and additive manufacture of a 3D printed snake skin-inspired texture pattern. The design functionalities of snake skin were determined through the study of the snake species Python Regius otherwise known as the ball python. Each scale of a snake has hierarchical texture with hexagonal macro-patterns aligned on the ventral surface of the skin with overriding anisotropic micro textured patterns such as denticulations and fibrils. Using a laser-powder bed fusion (L-PBF) process, 420 stainless steel samples were 3D printed which closely resemble the above described directional texture of natural snake skin. This printed surface ...


Optical Angular Scatterometry: In-Line Approach For Roll-2-Roll And Nano-Imprint Fabrication Systems, Juan Jose Faria-Briceno 2019 University of New Mexico

Optical Angular Scatterometry: In-Line Approach For Roll-2-Roll And Nano-Imprint Fabrication Systems, Juan Jose Faria-Briceno

Electrical and Computer Engineering ETDs

As critical dimensions continue to shrink and structures become more complex, metrology processes are challenging to implement during in-line nanomanufacturing. Non-destructive, non-contact, and high-speed conditions are required to achieve proper metrology processes during in-line manufacturing. Optical scatterometry is a nanoscale metrology tool widely used in integrated circuit manufacturing for characterization and quality control. However, most applications of optical scatterometry operate off-line. A high-speed, in-line, non-contact, non-destructive scatterometry angular system has been demonstrated in this work to scan pattern surfaces during real-time nano-fabrication.

Our system has demonstrated scanning capabilities using flat, 1D and 2D complex structures. The flat surface samples consist ...


Effect Of Annealing On The Contact Resistance Of Aluminum On A P-Type Substrate, Shrey Shah, George Patrick Watson 2019 Singh Center for Nanotechnology

Effect Of Annealing On The Contact Resistance Of Aluminum On A P-Type Substrate, Shrey Shah, George Patrick Watson

Protocols and Reports

Aluminum contacts are widely used to form both ohmic and rectifying contacts. The process to form these contacts involves annealing, thus it is important to study the effect of annealing on the electrical properties of the contacts. Here, we present a way to measure the contact resistance of aluminum contacts formed on a p-type silicon substrate. It was found the contact resistivity decreased by an average of 18%. It was thus found that annealing at 400°C in a forming gas environment improves the electrical properties of aluminum contacts.


Influence Of Flow Rate, Nozzle Speed, Pitch And The Number Of Passes On The Thickness Of S1805 Photoresist In Suss Microtec As8 Spray Coater, Rohan Sanghvi, Gyuseok Kim 2019 Singh Center for Nanotechnology

Influence Of Flow Rate, Nozzle Speed, Pitch And The Number Of Passes On The Thickness Of S1805 Photoresist In Suss Microtec As8 Spray Coater, Rohan Sanghvi, Gyuseok Kim

Tool Data

S1805 positive photoresist has been deposited on single crystalline Si wafers using a Suss MicroTec Alta Spray. The influence of flow rate, nozzle speed, pitch and number of passes on the thickness of the photoresist was studied. Results show that the thickness of S1805 is linearly proportional to the flow rate and number of passes, and inversely proportional to the nozzle speed and pitch.


Correction Of Pattern Size Deviations In The Fabrication Of Photomasks Made With A Laser Direct-Writer, Ningzhi Xie, George Patrick Watson 2019 Singh Center for Nanotechnology

Correction Of Pattern Size Deviations In The Fabrication Of Photomasks Made With A Laser Direct-Writer, Ningzhi Xie, George Patrick Watson

Protocols and Reports

When using Heidelberg DWL66+ laser writer to fabricate the photomask, the pattern feature dimensions may have deviations. These deviations can be caused by the lithography process and the undercut in the metal etch process. The same deviation value of 0.8µm was found to appear in all the patterns independent of the pattern original size and local pattern density. To overcome this universal deviation, a universal bias is suggested to be applied to the original patterns during the data preparation for the lithography process. In order to ensure this pre-exposure bias method can work, both the laser direct-write exposure conditions ...


Influence Of Naoh Concentration On Transfer Process Of Graphene, Francisco Saldana, Chengyu Wen, George Patrick Watson 2019 Singh Center for Nanotechnology

Influence Of Naoh Concentration On Transfer Process Of Graphene, Francisco Saldana, Chengyu Wen, George Patrick Watson

Protocols and Reports

The process of transferring a monolayer of graphene using two different concentrations of sodium hydroxide (NaOH) solution unto a silicon dioxide (SiO2) coated Si chip using electrochemistry was performed. The transfer process is crucial for the delamination of a continuous graphene monolayer film from copper foil. After examining and inspecting the integrity of the graphene monolayer, it was observed that the lower concentration to NaOH led to slower rate of hydrogen bubble generation; this condition was found to be less destructive and yielded a graphene film with fewer visible tears.


Investigation Of The Electrode Polarization Effect For Biosensor Applications, Anil Koklu 2019 Southern Methodist University

Investigation Of The Electrode Polarization Effect For Biosensor Applications, Anil Koklu

Mechanical Engineering Research Theses and Dissertations

My research focuses on electrokinetic transport. Particularly, in this dissertation, we focus on fabrication and testing of micro electrodes with nanostructured surfaces to minimize the electrode polarization (EP) effects for biosensor applications. In the first study, electrochemical deposition of gold nanoparticles on to planar gold electrodes was used to generate rough surfaces. Dendritic nanostructures that reduced EP up to two orders of magnitude was obtained by optimizing the deposition conditions. These structures also enhanced dielectrophoresis (DEP) response of our bio-chips, making them usable in physiological buffers. In further studies we discovered a universal scaling of EP in the frequency domain ...


Smart Charging Of Future Electric Vehicles Using Roadway Infrastructure, Sara Ahmed, Ethan Ahn, Mahmoud Reda Taha, Samer Dessouky, Moneeb Genedy, Daniel Fernandez, Ann Sebestian, Patience Raby 2019 University of Texas at San Antonio

Smart Charging Of Future Electric Vehicles Using Roadway Infrastructure, Sara Ahmed, Ethan Ahn, Mahmoud Reda Taha, Samer Dessouky, Moneeb Genedy, Daniel Fernandez, Ann Sebestian, Patience Raby

Data

Corresponding data set for Tran-SET Project No. 18ITSTSA03. Abstract of the final report is stated below for reference:

"Inspired by the fact that there is an immense amount of renewable energy sources available on the roadways such as mechanical pressure and frictional heat, this study presented the development and implementation of an innovative charging technique for future electric vehicles (EVs) by fully utilizing the existing roadways and the state-of-the-art nanotechnology and power electronics. The project introduced a novel wireless charging system, SIC (Smart Illuminative Charging), that uses LEDs powered by piezoelectric nanomaterials as the energy transmitter source and thin film ...


Toolpath Planning Methodology For Multi-Gantry Fused Filament Fabrication 3d Printing, Hieu Trung Bui 2019 University of Arkansas, Fayetteville

Toolpath Planning Methodology For Multi-Gantry Fused Filament Fabrication 3d Printing, Hieu Trung Bui

Theses and Dissertations

Additive manufacturing (AM) has revolutionized the way industries manufacture and prototype products. Fused filament fabrication (FFF) is one of the most popular processes in AM as it is inexpensive, requires low maintenance, and has high material utilization. However, the biggest drawback that prevents FFF printing from being widely implemented in large-scale production is the cycle time. The most practical approach is to allow multiple collaborating printheads to work simultaneously on different parts of the same object. However, little research has been introduced to support the aforementioned approach. Hence a new toolpath planning methodology is proposed in this paper. The objectives ...


Structural Health Monitoring Of Composite Parts: A Review, Jacob Pessin 2019 Union College - Schenectady, NY

Structural Health Monitoring Of Composite Parts: A Review, Jacob Pessin

Honors Theses

Structural health monitoring has the potential to allow composite structures to be more reliable and safer, then by using more traditional damage assessment techniques. Structural health monitoring (SHM) utilizes individual sensor units that are placed throughout the load bearing sections of a structure and gather data that is used for stress analysis and damage detection. Statistical time based algorithms are used to analyze collected data and determine both damage size and probable location from within the structure. While traditional calculations and life span analysis can be done for structures made of isotropic materials such as steel or other metals, composites ...


Symmetry And Dopant Diffusion In Inverted Nanopyramid Arrays For Thin Crystalline Silicon Solar Cells, Seok Jun Han 2019 University of New Mexico, Albuquerque

Symmetry And Dopant Diffusion In Inverted Nanopyramid Arrays For Thin Crystalline Silicon Solar Cells, Seok Jun Han

Chemical and Biological Engineering ETDs

In this dissertation, we enhance the efficiency of thin flexible monocrystalline silicon solar cells by breaking symmetry in light trapping nanostructures and improving homogeneity in dopant concentration profile. These thin cells are potentially less expensive than conventional thick silicon cells by using less silicon material and making the cells more convenient to be handled when supported on polymer films. Moreover, these cells are widely applicable due to their flexibility and lightweight. However, for high efficiencies, these cells require effective light trapping and charge collection. We achieve these in cells based on 14-mm-thick free-standing silicon films with light-trapping arrays of nanopyramidal ...


Plasmonic Properties Of Nanoparticle And Two Dimensional Material Integrated Structure, Desalegn Tadesse Debu 2019 University of Arkansas, Fayetteville

Plasmonic Properties Of Nanoparticle And Two Dimensional Material Integrated Structure, Desalegn Tadesse Debu

Theses and Dissertations

Recently, various groups have demonstrated nano-scale engineering of nanostructures for optical to infrared wavelength plasmonic applications. Most fabrication technique processes, especially those using noble metals, requires an adhesion layer. Previously proposed theoretical work to support experimental measurement often neglect the effect of the adhesion layers. The first finding of this work focuses on the impact of the adhesion layer on nanoparticle plasmonic properties. Gold nanodisks with a titanium adhesion layer are investigated by calculating the scattering, absorption, and extinction cross-section with numerical simulations using a finite difference time domain (FDTD) method. I demonstrate that a gold nanodisk with an adhesive ...


Characterization Of Hydride Vapor Phase Epitaxy Grown Gan Substrates For Future Iii-Nitride Growth, Alaa Ahmad Kawagy 2019 University of Arkansas, Fayetteville

Characterization Of Hydride Vapor Phase Epitaxy Grown Gan Substrates For Future Iii-Nitride Growth, Alaa Ahmad Kawagy

Theses and Dissertations

The aim of this research is to investigate and characterize the quality of commercially obtained gallium nitride (GaN) on sapphire substrates that have been grown using hydride vapor phase epitaxy (HVPE). GaN substrates are the best choice for optoelectronic applications because of their physical and electrical properties. Even though HVPE GaN substrates are available at low-cost and create the opportunities for growth and production, these substrates suffer from large macro-scale defects on the surface of the substrate.

In this research, four GaN on sapphire substrates were investigated in order to characterize the surface defects and, subsequently, understand their influence on ...


Gd5si4-Pvdf Nanocomposite Films And Their Potential For Triboelectric Energy Harvesting Applications, S. M. Harstad, P. Zhao, N. Soin, A. A. El-Gendy, Shalabh Gupta, Vitalij K. Pecharsky, J. Luo, Ravi L. Hadimani 2019 Virginia Commonwealth University

Gd5si4-Pvdf Nanocomposite Films And Their Potential For Triboelectric Energy Harvesting Applications, S. M. Harstad, P. Zhao, N. Soin, A. A. El-Gendy, Shalabh Gupta, Vitalij K. Pecharsky, J. Luo, Ravi L. Hadimani

Ames Laboratory Accepted Manuscripts

The triboelectric energy generators prepared using the combination of self-polarized, high beta-phase nanocomposite films of Gd5Si4-PVDF and polyamide-6 (PA-6) films have generated significantly higher voltage of 425 V, short-circuit current density of 30 mA/m(2) and a charge density of similar to 116.7 C/m(2) as compared to corresponding values of 300 V, 30 mA/m(2) and 94.7 mu C/m(2), respectively for the pristine PVDF-(PA-6) combination. The magnetic measurements of the Gd5Si4-PVDF films display a ferromagnetic behavior as compared to diamagnetic nature of pristine PVDF. The presence of magnetic nanoparticles in the ...


Reactive Ion Etching Selectivity Of Si/Sio2: Comparing Of Two fluorocarbon Gases Chf3 And Cf4, Meiyue Zhang, Pat Watson 2019 Singh Center for Nanotechnology

Reactive Ion Etching Selectivity Of Si/Sio2: Comparing Of Two fluorocarbon Gases Chf3 And Cf4, Meiyue Zhang, Pat Watson

Protocols and Reports

Two reactive ion etching (RIE) processes were studied to show the relative etch selectivity between SiO2 and Si using two fluorocarbon gases, CF4 and CHF3. Results show that CHF3 gives better selectivity (16:1) over CF4 (1.2 :1). On the other hand, the etch rate of SiO2 of CF4 is approximately 52.8 nm/min, faster than CHF3 (32.4 nm/min).


Energy Efficient Spintronic Device For Neuromorphic Computation, Md Ali Azam 2019 Virginia Commonwealth University

Energy Efficient Spintronic Device For Neuromorphic Computation, Md Ali Azam

Theses and Dissertations

Future computing will require significant development in new computing device paradigms. This is motivated by CMOS devices reaching their technological limits, the need for non-Von Neumann architectures as well as the energy constraints of wearable technologies and embedded processors. The first device proposal, an energy-efficient voltage-controlled domain wall device for implementing an artificial neuron and synapse is analyzed using micromagnetic modeling. By controlling the domain wall motion utilizing spin transfer or spin orbit torques in association with voltage generated strain control of perpendicular magnetic anisotropy in the presence of Dzyaloshinskii-Moriya interaction (DMI), different positions of the domain wall are realized ...


Digital Commons powered by bepress