Noncontact Liquid Crystalline Broadband Optoacoustic Sensors [U.S. Patent Us11366054b2], 2022 Air Force Institute of Technology
Noncontact Liquid Crystalline Broadband Optoacoustic Sensors [U.S. Patent Us11366054b2], Hengky Chandrahalim, Michael T. Dela Cruz
An optoacoustic sensor includes a liquid crystal (LC) cell formed between top and bottom plates of transparent material. A transverse grating formed across the LC cell that forms an optical transmission bandgap. A CL is aligned to form a spring-like, tunable Bragg grating that is naturally responsive to external agitations providing a spectral transition regime, or edge, in the optical transmission bandgap of the transverse grating that respond to broadband acoustic waves. The optoacoustic sensor includes a narrowband light source that is oriented to transmit light through the top plate, the LC cell, and the bottom plate. The optoacoustic sensor ...
Hinged Temperature-Immune Self-Referencing Fabry–Pérot Cavity Sensors [Us Patent Us11320596b2], 2022 Air Force Institute of Technology
Hinged Temperature-Immune Self-Referencing Fabry–Pérot Cavity Sensors [Us Patent Us11320596b2], Jeremiah C. Williams, Hengky Chandrahalim
A passive microscopic Fabry-Pérot Interferometer (FPI) sensor includes a three-dimensional microscopic optical structure formed on a cleaved tip of the optical fighter using a two-photon polymerization process on a photosensitive polymer by a three-dimensional micromachining device. The three-dimensional microscopic optical structure having a hinged optical layer pivotally connected to a distal portion of a suspended structure. A reflective layer is deposited on a mirror surface of the hinged optical layer while in an open position. The hinged optical layer is subsequently positioned in the closed position to align the mirror surface to at least partially reflect a light signal back ...
Porous Silicon Photonics For Label-Free Interferometric Biosensing And Flat Optics, 2022 Clemson University
Porous Silicon Photonics For Label-Free Interferometric Biosensing And Flat Optics, Tahmid Hassan Talukdar
This dissertation uses porous silicon as a material platform to explore novel optical effects in three domains: (i) It studies dispersion engineering in integrated waveguides to achieve high performance group index sensing. With proper design parameters, the sensor waveguides can theoretically achieve 6 times larger group index shift compared to the actual bulk effective refractive index shift. We demonstrate the guided mode confinement factor to be a key parameter in design and implementation of these waveguides. (ii) It explores multicolor laser illumination to experimentally demonstrate perceptually enhanced colorimetric sensing, overcoming the limitations faced by many contemporary colorimetric sensors. Our technique ...
Iii-Nitride Nanostructures: Photonics And Memory Device Applications, 2021 New Jersey Institute of Technology
Iii-Nitride Nanostructures: Photonics And Memory Device Applications, Barsha Jain
III-nitride materials are extensively studied for various applications. Particularly, III-nitride-based light-emitting diodes (LEDs) have become the major component of the current solid-state lighting (SSL) technology. Current III-nitride-based phosphor-free white color LEDs (White LEDs) require an electron blocking layer (EBL) between the device active region and p-GaN to control the electron overflow from the active region, which has been identified as one of the primary reasons to adversely affect the hole injection process. In this dissertation, the effect of electronically coupled quantum well (QW) is investigated to reduce electron overflow in the InGaN/GaN dot-in-a-wire phosphor-free white LEDs and to improve ...
Synthetic Aperture Optical Imaging Interferometric Microscopy With Improved Image Quality, 2021 University of New Mexico - Main Campus
Synthetic Aperture Optical Imaging Interferometric Microscopy With Improved Image Quality, Preyom K. Dey
Electrical and Computer Engineering ETDs
The resolution limit of optical microscopy can be extended by using Imaging Interferometric Microscopy (IIM), which uses a low numerical aperture (NA) objective lens to achieve resolution equivalent to that of a high-NA objective lens with multiple sub-images. Along with the resolution enhancement challenge, IIM often suffers from poor image quality. In this dissertation, several image quality improvement methods are proposed and verified with simulation and experimental results. Next, techniques to extend the resolution limit of IIM to ≤ 100nm using a low-NA objective lens are demonstrated. An experimental technique of using a grating coupler on a planar waveguide ...
Machine Learning Approach To Stability Analysis Of Semiconductor Memory Element, 2021 Southern Methodist University
Machine Learning Approach To Stability Analysis Of Semiconductor Memory Element, Ravindra Thanniru, Gautam Kapila, Nibhrat Lohia
SMU Data Science Review
Memory stability analysis traditionally relied heavily on circuit simulation-based approaches that run Monte Carlo (MC) analysis over various manufacturing and use condition parameters. This paper researches application of Machine Learning approaches for memory element failure analysis which could mimic simulation-like accuracy and minimize the need for engineers to rely heavily on simulators for their validations. Both regressor and classifier algorithms are benchmarked for accuracy and recall scores. A high recall score implies fewer escapes of fails to field and is the metric of choice for comparing algorithm. The paper identifies that recall score in excess of 0.97 can be ...
Incorporation Of Zinc In Pre-Alloyed Cuin[Zn]S2/Zns Quantum Dots, 2021 University of Arkansas, Fayetteville
Incorporation Of Zinc In Pre-Alloyed Cuin[Zn]S2/Zns Quantum Dots, Jean Carlos Morales Orocu
Graduate Theses and Dissertations
Since the early 2000s heavy-metal-free quantum dots (QDs) such as CuInS2/ZnS have attempted to replace CdSe, their heavy-metal-containing counterparts. CuInS2/ZnS is synthesized in a two-step process that involves the fabrication of CuInS2 (CIS) nanocrystals (NCs) followed by the addition of zinc precursors. Instead of the usual core/shell architecture often exhibited by binary QDs, coating CIS QDs results in alloyed and/or partially alloyed cation-exchange (CATEX) QDs. The effect that zinc has on the properties of CIS NCs was studied by incorporating zinc during the first step of the synthesis. Different In:Cu:Zn ratios were employed in ...
Additive Manufacturing Using Robotic Manipulators, Fdm, And Aerosol Jet Printers., 2021 University of Louisville
Additive Manufacturing Using Robotic Manipulators, Fdm, And Aerosol Jet Printers., Alexander Curry
Electronic Theses and Dissertations
Additive manufacturing has created countless new opportunities for fabrication of devices in the past few years. Advances in additive manufacturing continue to change the way that many devices are fabricated by simplifying processes and often lowering cost. Fused deposition modeling (FDM) is the most common form of 3D printing. It is a well-developed process that can print various plastic materials into three-dimensional structures. This technology is used in a lot of industries for rapid prototyping and sometimes small batch manufacturing. It is very inexpensive, and a prototype can be created in a few hours, rather than days. This is useful ...
Make And Characterize Microfluidic Devices With Gelatin: Do-It-Yourself (Diy) Laboratory At Home, 2021 University of Pennsylvania
Make And Characterize Microfluidic Devices With Gelatin: Do-It-Yourself (Diy) Laboratory At Home, Marissa Youderian, Xilai Song, Mark Lancaster, Ahana Jhamb, David J. Jones, Gyuseok L. Kim
Microfluidic devices have been fabricated with gelatin and paper clips. Optimization of fabrication and characterization process has been carried out systemically by varying gelatin-to-water ratio, bonding time and connector type. We find that the higher gelatin-to-water ratio and the luer lock syringe tip provide a greater success rate, whereas the influence of bonding time is limited. The Reynolds number was calculated to identify whether the fluid shows laminar or turbulent flow.
Mems Device Demonstration For High School Students Or Nonspecialists, 2021 University of Pennsylvania
Mems Device Demonstration For High School Students Or Nonspecialists, Jeffrey Meng, Gyuseok L. Kim, Gabriel Unger
Micro-electromechanical systems (MEMS) devices have many unique advantages, and offer an exciting entrance for students into the field of nanotechnology and nanofabrication. In this article, an educational hands-on laboratory protocol with MEMS devices is proposed. Using a paper airplane, an Arduino, and the MPU 6050 MEMS accelerometer/gyroscope sensor students are able to create a graphical aircraft attitude indicator. The data is then processed on the Arduino, which is connected to a computer. The computer can then run graphics software displaying a digital aircraft attitude indicator showing the roll and pitch of the aircraft live.
Modeling And Characterization Of Optical Metasurfaces, 2021 University of Massachusetts Amherst
Modeling And Characterization Of Optical Metasurfaces, Mahsa Torfeh
Metasurfaces are arrays of subwavelength meta-atoms that shape waves in a compact and planar form factor. During recent years, metasurfaces have gained a lot of attention due to their compact form factor, easy integration with other devices, multi functionality and straightforward fabrication using conventional CMOS techniques. To provide and evaluate an efficient metasurface, an optimized design, high resolution fabrication and accurate measurement is required. Analysis and design of metasurfaces require accurate methods for modeling their interactions with waves. Conventional modeling techniques assume that metasurfaces are locally periodic structures excited by plane waves, restricting their applicability to gradually varying metasurfaces that ...
Towards Higher Power Factor In Semiconductor Thermoelectrics: Bandstructure Engineering And Potential Barriers, 2021 University of Massachusetts Amherst
Towards Higher Power Factor In Semiconductor Thermoelectrics: Bandstructure Engineering And Potential Barriers, Adithya Kommini
To keep up with the current energy demand and to sustain the growth requires efficient use of existing resources. One of the ways to improve efficiency is by converting waste heat to electricity using thermoelectrics. Thermoelectric devices work on the principle of Seebeck effect, where an applied temperature difference across the material results in a potential difference in the material. The possibility of drastic improvements in the efficiency of thermoelectric (TE) devices using semiconductor nanostructured materials renewed interest in thermoelectrics over the last three decades. Introducing confinement, interfaces, and quantum effects using nanostructures for additional control of charge and phonon ...
Tailoring Plasmon Excitations In Alpha − T 3 Armchair Nanoribbons, 2021 CUNY Medgar Evers College
Tailoring Plasmon Excitations In Alpha − T 3 Armchair Nanoribbons, Andrii Iurov, Liubov Zhemchuzhna, Godfrey Gumbs, Danhong Huang, Paula Fekete, Farhana Anwar, Dipendra Dahal, Nicholas Weekes
Publications and Research
We have calculated and investigated the electronic states, dynamical polarization function and the plasmon excitations for α − T 3 nanoribbons with armchair-edge termination. The obtained plasmon dispersions are found to depend significantly on the number of atomic rows across the ribbon and the energy gap which is also determined by the nanoribbon geometry. The bandgap appears to have the strongest effect on both the plasmon dispersions and their Landau damping. We have determined the conditions when relative hopping parameter α of an α − T 3 lattice has a strong effect on the plasmons which makes our material distinguished from graphene ...
Improving Healthspan Through Patient-Derived Artificial Organs From Induced Pluripotent Stem Cells And Two-Photon Polymerization, 2021 University of Pennsylvania
Improving Healthspan Through Patient-Derived Artificial Organs From Induced Pluripotent Stem Cells And Two-Photon Polymerization, Connor Espenshade
Protocols and Reports
Senescence, from the shortening of telomeres, accumulation of mutations, epigenetic hypomethylation, and other causes, begins an eventual cycle of decline in every patient. Stem cells disappear as a function of age, which in turn impairs cellular replication. Moreover, when fully differentiated cells are induced back into induced pluripotent stem cells (iPSCs), they not only revert to a state of pre-differentiation, but also to a younger cellular age. Their aging clocks turn back: their telomeres become longer and DNA methylation reverts back to an earlier age. It should therefore be possible to use iPSCs to replace the missing stem cells from ...
Development Of A Point-Of-Use Testing Platform For Detecting Bacteria Infection In Raw Milk, 2021 University of Tennessee, Knoxville
Development Of A Point-Of-Use Testing Platform For Detecting Bacteria Infection In Raw Milk, Xin Xia
The detection and quantification of bacteria are essential to environment and food quality monitoring. Escherichia coli (E. coli) is a common pathogen, also a causative agent of mastitis. Traditional methods usually require samples to be tested in a laboratory. However, sending samples to remote lab increases the cost of time and money spent on delivery. Sometimes, samples can degrade during this long progress and cause inaccuracy. A low cost and reusable sensor is designed to perform on-site quantification. The sensor composed of two layers of asymmetrical mesh electrodes, which is used in coordination magnetic microparticles functionalized with bacterium-specific antibody. Immunological ...
The Effects Of The Transient And Performance Loss Rates On Pv Output Performance, 2021 Technological University Dublin
The Effects Of The Transient And Performance Loss Rates On Pv Output Performance, Chibuisi Chinasaokwu Okorieimoh, Brian Norton, Michael Conlon
Solar photovoltaic (PV) panels experience long-term performance degradation as compared to their initial performance, resulting in lower like-per-like efficiencies and performance ratios. Manufacturers of solar photovoltaic modules normally guarantee a lifespan of more than 20 years. To meet such commitments, it is important to monitor and mitigate PV module degradation during this period, as well as beyond, to recognize maintenance and repair needs. Solar PV modules degrade over time, becoming less effective, less reliable, and eventually unusable. The effects of transient and performance loss rates on the output performance of polycrystalline silicon (p-Si) solar PV modules are the focus of ...
Design And Characterization Of Standard Cell Library Using Finfets, 2021 California Polytechnic State University, San Luis Obispo
Design And Characterization Of Standard Cell Library Using Finfets, Phanindra Datta Sadhu
The processors and digital circuits designed today contain billions of transistors on a small piece of silicon. As devices are becoming smaller, slimmer, faster, and more efficient, the transistors also have to keep up with the demands and needs of the daily user. Unfortunately, the CMOS technology has reached its limit and cannot be used to scale down due to the transistor's breakdown caused by short channel effects. An alternative solution to this is the FinFET transistor technology, where the gate of the transistor is a three dimensional fin that surrounds the transistor and prevents the breakdown caused by ...
Effect Of Developer Temperature On Photoresist Contrast In Grayscale Lithography, 2021 Singh Center for Nanotechnology
Effect Of Developer Temperature On Photoresist Contrast In Grayscale Lithography, Dale Farnan, George Patrick Watson
Protocols and Reports
SPR 220-3 photoresist was spin-coated onto a silicon wafer, exposed using a Heidelberg DWL66+ laserwriter at different laser powers, and developed at different temperatures. The effect of developer temperature on photoresist contrast was examined. Results show that increasing developer temperature decreased photoresist contrast and increased required dose.
Optoelectronic Valley-Spin Qubits With Ambipolar Quantum Dots, 2021 University of Arkansas, Fayetteville
Optoelectronic Valley-Spin Qubits With Ambipolar Quantum Dots, Jeremy Tull
Electrical Engineering Undergraduate Honors Theses
The current limitations of qubit-based processors are caused by imperfections in quantum gates, leading to a lack of gate fidelity. Gate fidelity can be refined by extending the coherence of qubits and reducing logic operation speed. A potential solution is to develop a hybrid qubit that has the coherence of electrically-controlled quantum dots and the gate speed of their optically-controlled counterparts. Quantum bits that utilize ultrafast optical gating to perform gate operations require precise control of the gating pulse duration. Optical dispersion can cause adverse effects pulse duration, such as pulse broadening, so dispersion-compensation techniques must be employed; by properly ...
Design And Fabrication Of A Microstrip Bandpass Filter In Ltcc, 2021 University of Arkansas, Fayetteville
Design And Fabrication Of A Microstrip Bandpass Filter In Ltcc, Allison Rucker
Electrical Engineering Undergraduate Honors Theses
The goal of the project was to design and fabricate a bandpass filter with a center frequency of 25GHz with a 2GHz bandwidth. The first step was to do the calculation to design a bandpass filter to meet these specifications along with the properties of the DupontTM GreenTapeTM 9K7. HFSS was then used to verify the results from the initial calculations. There was a significant error between the two results, so more tweaking was done to the calculations to get a better center frequency. After a final design was decided, the fabrication process started. Low-Temperature Co-Fired Ceramics (LLTC ...