Mechanical Engineering Commons^™

Evaluation Of Digital Twin Approaches For Thermal Modeling And Energy Optimization For Existing Buildings, Jason Bastie Muermann

Theses and Dissertations

Residential, commercial, and industrial building sectors in the United States were responsible for 42% of the nation’s consumption of 100.2 quadrillion BTUs of energy in 2019 [1]. 80% of the nation’s energy is sourced from fossil fuels, including coal, natural gas, and petroleum. Fossil fuels are known contributors to carbon emissions and climate change, making energy reduction vital. Consequently, New Jersey Department of Military and Veterans Affairs (NJDMAVA) is tasked with evaluating energy consumption and efficiency in all New Jersey Army National Guard (NJARNG) facilities, as mandated by TAG Policy Letter 18-5, Executive Order 13990, and the Energy Independence and …

Development Of A Modular Agricultural Robotic Sprayer, Paolo Rommel P. Sanchez

Theses and Dissertations

Precision Agriculture (PA) increases farm productivity, reduces pollution, and minimizes input costs. However, the wide adoption of existing PA technologies for complex field operations, such as spraying, is slow due to high acquisition costs, low adaptability, and slow operating speed. In this study, we designed, built, optimized, and tested a Modular Agrochemical Precision Sprayer (MAPS), a robotic sprayer with an intelligent machine vision system (MVS). Our work focused on identifying and spraying on the targeted plants with low cost, high speed, and high accuracy in a remote, dynamic, and rugged environment. We first researched and benchmarked combinations of one-stage convolutional …

Flexural Wave Manipulation By Non-Hermitian Planar Elastic Metasurface, Katerina Stojanoska

Theses and Dissertations

It has been demonstrated that metasurfaces with spatially asymmetric inner geometry exhibit unidirectional scattering effects, which can be used to control waves in a directional fashion. In this thesis, a planar Non-Hermitian elastic metasurface exhibiting unidirectional focusing of flexural waves is proposed. Asymmetrically loaded piezoelectric disks and metallic blocks comprise the unit cells. By using a negative capacitance shunting, a tunable material loss is embedded into the system. With suitable engineering of the induced loss profile, resonating building blocks are designed, which are capable of independently accessing unidirectional zero reflection. A planar metasurface is then created so that constructive interference …

A 3d Bioprinted Hydrogel Microfluidic Device For Screening Applications, Anant Bhusal

Theses and Dissertations

The microfluidic enabled the integration of engineered miniaturized tissue models for drug screening. Conventional polydimethylsiloxane or plastic-based devices require multiple fabrication steps, which are challenging. We developed a 3D bioprinting approach to create prototypes of hydrogel-based multi-material microfluidic devices integrated with microtissue models. The approach utilizes poly(ethylene glycol) diacrylate and gelatin-methacryloyl to create microfluidic chips using multi-material bioprinting capacity with a high resolution of 15µm on x-y and 50µm on the z-axis and post-printing viability of >90%. We demonstrated easy regulation of stiffness from 24±5 kPa to 1,180±9 kPa and burst pressure from 16±1kPa to 256±19 kPa in the chip …

Using Dielectric Scatters To Selectively Excite Embedded Eigenstates In Cavity Resonators, Olugbenga Joshua Gbidi

Theses and Dissertations

Bound states in the continuum (BICs) are waves that remain in the continuous spectrum of radiating waves that carry energy, however, still localized within the spectrum. BICs, also embedded eigenmodes, exhibit high quality factors that have been observed in optical and acoustic waveguides, photonic structures, and other material systems. Presently, there are limited means to select these BICs in terms of the quality factor and their excitation. In this work, we show that a different type of BIC, Quasi-BICs (Q-BICs), in open resonators can have their quality attuned by introducing embedded scatters. Using microwave cavities and dielectric scatters as an …

Investigation Of Polymer Nanocomposites With Silicon Dioxide Fillers As Helium Cooled High-Temperature Superconducting Cable Dielectrics, Jordan Thomas Cook

Theses and Dissertations

In this thesis, three polymer nanocomposite configurations are fabricated for investigation as dielectrics in helium-cooled high-temperature superconducting (HTS) cables. Polyimide, polyamide, and polymethyl methacrylate are utilized as host polymers. The composite samples are synthesized through an in situ process, dispersing silicon dioxide nanoparticles throughout the polymer hosts. Fourier transform infrared spectroscopy and scanning electron microscopy were employed to validate the synthesis of each composite configuration. Thin film samples of each configuration were also tested for their dielectric strength at both room (300 K) and cryogenic (92 K) temperatures. When going from room to cryogenic temperatures, all materials demonstrated a significant …

Investigation Of Adhesion, Deformation Mechanics, And Electrical Properties Of Ag/Sio2/Pdms Tri-Layers For Stretchable Electronic Applications, Rhandy Joe Paladines

Theses and Dissertations

The motivation behind this research is to improve the interfacial layer bonding of metallic thin films to PDMS substrates with the aid of a buffer layer. The physical vapor deposition (PVD) technique of sputtering was used to deposit bilayer thin films of silver (Ag) and silicon dioxide (SiO2) on PDMS. Two chamber pressures were used in this work, 5 and 20 mTorr, to investigate the role of this parameter in determining the interfacial adhesion and the role in determining the resistance sensitivity. Studies of the surface energy and increased bonding strength for metallization are carried out. Surface characterization using atomic …

Electro-Mechanical Data Fusion For Heart Health Monitoring, Kemal Yakut

Theses and Dissertations

Heart disease is a major public health problem and one of the leading causes of death worldwide. Therefore, cardiac monitoring is of great importance for the early detection and prevention of adverse conditions. Recently, there has been extensive research interest in long-term, continuous, and non-invasive cardiac monitoring using wearable technology. Here we introduce a wearable device for monitoring heart health. This prototype consists of three sensors to monitor electrocardiogram (ECG), phonocardiogram (PCG), and seismocardiogram (SCG) signals, integrated with a microcontroller module with Bluetooth wireless connectivity. We also created a custom printed circuit board (PCB) to integrate all the sensors into …

Design And Control Of Modular Soft Robotic Actuators With Architected Structures, Nicholas Pagliocca

Theses and Dissertations

Soft robotic systems composed of highly compliant materials offer unparalleled advantages compared to rigid-body systems in applications such as fragile material handling and human-machine interactions. Often, their motions are prescribed by structural anisotropy and reinforcement materials to directionally limit motion. The continuum motion and non-linear material response intrinsic to soft robotics makes their design, modeling, and control a formidable challenge for engineers. Leveraging the deformation driven response of soft robotic actuators, highly versatile compliant architected structures whose local deformations dictate global material response can be integrated into soft robotic actuators for tunable mechanical responses. In this thesis, flexible center-symmetric perforated …

Experimental Characterization And Manufacture Of Polymer Nanocomposite Dielectric Coatings For High-Temperature Superconductor Applications, Jacob Ryan Mahon

Theses and Dissertations

Increased implementation of high-temperature superconducting (HTS) power transmission has the potential to revolutionize the efficiency of electrical grids and help unlock a fully electric transportation infrastructure. Realizing the benefits of HTS systems has been impeded by a lack of available dielectric insulation materials that can 1) withstand the extreme cryogenic operating environment of superconductors and 2) demonstrate low temperature processing that is compatible with existing superconductor manufacturing methods. Solving this problem necessitates a high-performance dielectric material with multifunctional properties specifically suited for operation in HTS systems. A polyamide and silicon dioxide (PA/SiO2) nanocomposite material with exceptional thermal stability has been …

Standards-Compatible Smoke Points For Mono- And Un- Substituted Cycloalkane Fuel Components, Adekunle Vincent Adeniyi

Theses and Dissertations

Emissions from the aviation industry have increased significantly over the decades and may continue to pose an environmental threat. Accordingly, efforts are being made to replace conventional aviation fuels with more sustainable alternatives that can both reduce net CO2 emissions as well as reduce other pollutants (i.e., particulates). Conventional jet fuels include aromatic species, which have high sooting tendency. Therefore, to reduce particulate emissions, the fuel aromatics content must be reduced. Cycloalkanes have potential for replacing aromatics content in jet fuel but, compared to other broad classes of chemical species that make up conventional and alternative jet fuel, there is …

Algorithms For Rapid Trip Detection In Human Walking Using Inertial Sensors, Chadi Ellouzi

Theses and Dissertations

Trips and falls are one of the most common causes for injuries among elderly. The existing trip-and-falls studies primarily focus on the proactive fall prevention approaches, while active prevention strategies remain largely unexplored. This thesis aims to provide first steps towards active trip-and-fall prevention by developing various algorithms capable of detecting trip in human walking faster than the human voluntary reactions (~200 ms). The measurements of human kinematics are used as the inputs in the algorithms. The proposed algorithms include three threshold-based detection methods, an optimized elastic time-series alignment tool called dynamic time warping (DTW) that overcomes problems of time …

Rainbow Trapping Effect In 2d Axisymmetric Broadband Acoustic Energy Harvesters, Louis Alexander Gormley

Theses and Dissertations

Acoustic energy harvesters (AEHs) collect otherwise unused ambient acoustic waves for conversion into useful electrical energy. This promising technology has potential applications ranging from grid-independent electronics to structural health monitoring systems. AEHs capture specific acoustic frequencies of interest using structures with frequency-matched component geometries. Despite the multitude of potential geometries suitable for AEH structures, existing AEH research has predominantly focused on the acoustic wave trapping performance of unidimensional or linear bidimensional AEH structures.

This study intended to broaden AEH bandwidth and capture efficiency by investigating the acoustic rainbow trapping performance of a novel 2D axisymmetric AEH design. A Finite Element …

Design Of An Inexpensive Pvc Shock Tube For Educational Use, Brandon Edward Bergmann

Theses and Dissertations

Herein is described the design and function of a low-cost, easy-to-assemble, -operate, and -disassemble shock tube platform experiment that can generate shock waves approaching Mach 2 at maximum pressures of ~100 psig with a helium driver gas. The experiment uses several inexpensive (<$5), unamplified piezoelectric sensors attached to a multichannel oscilloscope to monitor the passage of key features of the flow (i.e., incident shock and reflected shock) through the tube, constructed from inexpensive and easy to work with schedule 40 PVC pipe and fittings. From the fixed sensor displacements along the tube and relative differences in respective transit times, the velocities of these flow features can be determined. This permits (1) comparison of experimental results to the theoretical predictions of 1-D transient gas dynamics and (2) a leaping off point for discussion and quantification of non-idealities in the flow, including the shock wave development length, shock attenuation and boundary layer growth, and interactions of the reflected shock and contact surface. Experimental accessories (future work) for study of shock focusing and steady 2-D high speed flows are also briefly discussed. Assuming both pressurized, conditioned air at ~80-100 psig and a modern multi-channel oscilloscope are available at most institutions, the total cost to construct this experiment is around $500.

An Examination Of The Influence Of Distillation On The Combustion Behavior Of Apparently Equivalent Surrogate Fuels, Jay A. Lefkowitz

Theses and Dissertations

Use of surrogates to emulate the combustion behaviors of prevaporized real fuels has been widely demonstrated in the literature. However, many combustion applications utilize atomized fuel sprays, and for these configurations, the assumption of fuel property homogeneity in prevaporized fuel combustion is tenuous. This work uses a simplified distilling droplet model to demonstrate a real potential for vaporization-coupled deviations from the single-valued combustion property targets used to characterize prevaporized combustion behaviors. To verify the model-based observations, flame blowout measurements from a custom-built annular spray burner rig are measured. Sets of essentially equivalent prevaporized jet fuel and gasoline surrogates suggested in …

Optimization Of Load-Bearing And Impact Energy Absorption Capacities Of Honeycomb Structures By Density Gradation, Oyindamola Khadijat Rahman

Theses and Dissertations

Density gradation has been analytically and experimentally proven to enhance the load-bearing and energy absorption efficiency of cellular solids. This research focuses on the analytical optimization (by virtual experiments) of polymeric honeycomb structures made from flexible thermoplastics to achieve density-graded structures with desired mechanical properties. The global stress-strain curves of single-density honeycomb structures are used as input to an analytical model that enables the characterization of the constitutive response of density-graded hexagonal honeycombs with discrete and continuous gradations and for various gradients. The stress-strain outputs are used to calculate the specific energy absorption, efficiency, and ideality metrics for all density-graded …

Design Of A Pneumatic Soft Robotic Actuator Using Model-Based Optimization, Mahsa Raeisinezhad

Theses and Dissertations

In this thesis, the design and optimization process of a novel soft intelligent modular pad (IntelliPad) for the purpose of pressure injury prevention is presented. The structure of the IntelliPad consists of multiple individual multi-chamber soft pneumatic-driven actuators that use pressurized air and vacuum. Each actuator is able to provide both vertical and horizontal motions that can be controlled independently. An analytical modeling approach using multiple cantilever beams and virtual springs connected in a closed formed structure was developed to analyze the mechanical performance of the actuator. The analytical approach was validated by a finite element analysis. For optimizing the …

In Situ Characterization Of Fiber-Matrix Interface Debonding Via Full-Field Measurements, Robert Livingston

Theses and Dissertations

Macroscopic mechanical and failure properties of fiber-reinforced composites depend strongly on the properties of the fiber-matrix interface. For example, transverse cracking behavior and interlaminar shear strength of composites can be highly sensitive to the characteristics of the fiber-matrix interface. Despite its importance, experimental characterization of the mechanical behavior of the fiber-matrix interface under normal loading conditions has been limited. This work reports an experimental approach that uses in situ full-field digital image correlation (DIC) to quantify the mechanical and failure behaviors at the fiber-matrix interface. Single fiber model composite samples are fabricated from a proprietary epoxy embedding a single glass …

Numerical Modeling Of The Fiber Deposition Flow In Extrusion-Based 3d Bioprinting, Dhanvanth Jaya Talluri

Theses and Dissertations

Extrusion bioprinting involves the deposition of bioinks in a layer-wise fashion to build 3D structures that mimic natural living systems' behavior in tissue engineering. Hydrogels are the most common bioinks, in which their viscosity properties are dependent on the shear-rate, such as Non-Newtonian fluids. Numerical simulation of extrusion bioprinting may help study the flow properties of hydrogels and designing improved bioinks. In this thesis, the instability caused by the shear-thinning or -thickening parameter during extrusion is numerically compared with the theoretical estimations. The process of fiber deposition of hydrogels onto a substrate through the single and coaxial nozzle is done …

Discrete Element Modeling Of Hydrogel Extrusion, Rohit Boddu

Theses and Dissertations

Hydrogels are widely used in extrusion bioprinting as bioinks. Understanding how the hydrogel microstructure affects the bioprinting process aids researchers in predicting the behavior of biological components. Current experimental tools are unable to measure internal forces and microstructure variations during the bioprinting process. In this work, discrete element modeling was used to study the internal interactions and the elastic deformation of the molecular chains within hydrogel networks during the extrusion process. Two-dimensional models of hydrogel extrusions were created in Particle Flow Code (PFC; Itasca Co., Minneapolis, MN). For our model's calibration, hydrogel compression testing was used in which a cluster …

Exploring A Platinum Nanocatalytic Microcombustion-Thermoelectric Coupled Device, Dylan Moore Mcnally

Theses and Dissertations

This work aimed to create a first-generation power device for eventual application to portable electronics. A platinum nanoparticle catalytic substrate was employed in a microcombustion-thermoelectric coupled (MTC) device for the purpose of chemical-to-electrical energy conversion. Multiple microcombustion reactors were designed, fabricated, and investigated. Most importantly, the reactor configuration was designed to accommodate thermoelectric generators (TEGs) for power production. Temperature studies with catalytic combustion of methanol-air fuel mixtures were used to evaluate the thermal power generation performance of each reactor. The final reactor design enabled ignition at room temperature with the ability to achieve repeat catalytic cycles upon subsequent exposure to …

Bioprinted In Vitro Model Of Human Glioblastoma, Rachel Lauren Schwartz

Theses and Dissertations

Glioblastoma multiform (GBM) is one of the most aggressive forms of primary brain tumors. GBM is fast progressing and resistant to treatment, resulting in a low survival rate. Conventional 2-dimensional tissue culture models cannot fully replicate the complexities of cancer lesions that contain multiple cell types and structures (e.g. vessels composed of endothelial cells, cancer cells, normal cells, etc.) as well as an intricate scaffold of proteins comprising the extracellular matrix (ECM). In addition, animal models cannot translate into the clinical disease in patients. Thus, this study has developed a bioprintable organ-on-a-chip (OOAC) model that mimics the important ECM factors …

Polyimide/Silicon Dioxide Nanocomposites As Dielectrics For Helium-Cooled High-Temperature Superconducting Cables, Harrison Michael Hones

Theses and Dissertations

In this thesis, polyimide (PI) and silicon dioxide (SiO2) were combined in the form of a nanocomposite for use as a dielectric on helium-cooled high-temperature superconducting (HTS) cables. Further, a cryogenic chamber was designed with the intent of cooling samples to 40 K for dielectric and thermal contraction testing. Composites were created through an in situ process which resulted in nanoparticle formation within the host matrix. Samples were tested for dielectric strength at room temperature (300 K) as well as cryogenic temperature (92 K) using liquid nitrogen as the coolant. Composite samples tested at 300 K averaged a dielectric strength …

Improving The Piezoelectric Properties Of Flexible Polymer-Nanoparticle Energy Harvesters, Muhammet Emin Cavusoglu

Theses and Dissertations

In this research, one of the widely used polymers, poly(vinylidene fluoride)(PVDF), was used to develop thin-film polymer energy harvesters. Dimethylformamide (DMF) and methyl ethyl ketone (MEK) were used to dissolve the PVDF powder. Four different (0%, 3%, 5%, and 7%) ZnO nanoparticle (NP) concentrations were used to enhance the electrical output of the thin-film energy harvesters. A sonication bath and additional MEK were used in dispersing the ZnO NPs to obtained uniform PVDF/ZnO NP solution. The electrode poling technique was used for dipole alignment to improve the electrical performance of the devices. The fabricated samples were tested using the tensile …

The Impact Of Patient-Specific Vascular Structure On Localized Cooling In The Human Heart, Nathan Paul Spangenberg

Theses and Dissertations

Acute Myocardial Infarction (AMI) is the leading cause of worldwide death and disability, and approximately 720,000 Americans will experience an AMI in 2018. Studies have shown that rapid hypothermia therapy (<35°C) before reperfusion in patients with AMI can reduce infarct size by 37%. Localized therapeutic hypothermia has proven the potential to cool heart tissue rapidly following AMI, 3°C in 5 minutes. Using Materialise Mimics digital imaging software and the finite volume method we analyzed temperature distributions in six patient-specific left main coronary artery (LMCA) models. A mock circulatory loop was used to determine the exiting temperatures of a standard 7 Fr catheter to feed into our model with flow rates ranging from 29.2 ml/min to 68.85 ml/min. Our work showed that therapeutic hypothermia (TH) temperatures were evident at the outlets of three out of all six heart models, which varied in each left anterior descending (LAD) and left circumflex (LCX) artery depending on flowrate. Results of this study indicate that biovariability in patient-specific vascular structures significantly impacts therapeutic hypothermia (TH) treatment methods. These results indicate that further research is needed to examine more accurate physiological effects, such as pulsatile flow and vessel wall thickness. Future models will be used to provide insight to guide more efficient TH device designs and operation parameters to optimize patient outcomes following AMI.

Initial Development Of A Prototype Sensor Testbed For Fetal Monitoring, Christian Beauvais

Theses and Dissertations

The objective of this research is to design and manufacture a device that exhibits some of the bio-physiological signals relevant to fetal health monitoring. Currently, limited options exist for testing the performance of monitoring devices such as the tocodynamometer (TOCO) and electrocardiograph (ECG) that measure the bio-physiological signals of a woman and her fetus. Sensor designers need ways of generating and acquiring signals that do not carry the ethical burden of human testing. The development of such a device, as considered in this work, may involve using muscle wire or an inflatable tube as prospective foundations for simulating uterine contraction. …

Functional Porous Polydimethlysiloxane As Piezoresistive And Piezoelectric Materials, Taissa Rose Michel

Theses and Dissertations

In this paper, polydimethylsiloxane (PDMS), carbon nanotubes (CNTs), and zinc oxide (ZnO) were combined to create functionalized piezoresistive and piezoelectric sensors for pressure sensing and energy harvesting. Samples were foamed to show that the increased deformability of the foam sensors makes them suitable for a range of applications including dexterous robotics, tactile sensing, energy harvesting, and biosensing. Uniform dispersion of CNTs was achieved with chloroform as the solvent. Samples were foamed using chemical blowing and scaffolding but granulated sugar at 70% porosity resulted in foamed samples with the most consistent mechanical properties. Samples underwent tensile and compressive testing for their …

A Study Of Catalytic Microcombustion For A Portable Power Supply Device, Bhanuprakash Reddy Guggilla

Theses and Dissertations

The essential need for portable and dense power sources has been greatly increased with the prevalence of portable electronic devices in the past decade. Catalytic combustion of hydrocarbon and oxygenated fuels has the potential to provide an alternative power source for portable electronic devices by replacing relatively today's heavy battery technology. A successful self-ignition and sustainable catalyst combustion for a variety of fuels using Platinum (Pt)-impregnated substrate was demonstrated in our previous work.

Present work explores the performance of a microcombustion thermoelectric coupled (MTC) device with improved reactor configuration design. Chemically synthesized platinum nanoparticles with particle diameters of approx. 8 …

Efficacy Of Eluted Antibiotics In 3d Printed Orthopaedic Implants, Mohammed Mehdi Benmassaoud

Theses and Dissertations

Costs associated with musculoskeletal diseases in the United States account for 5.7 % of the Gross Domestic Product (GDP) [1]. As such, there is a need to pursue new ideas in orthopaedic implants that can decrease cost and improve patient care. In the recent years, 3D printing using Fused Deposition Modeling (FDM) or Stereolithography (SLA) has opened several exciting possibilities to create orthopaedic implants. Such implants can be engineered to release antibiotics in a controlled manner either by infusing the drug into the material during manufacturing or by using built-in design features such as micro-channels and reservoirs [2]. The use …

Perovskite Solar Cells Fabricated Via Scalable Dip Coating Methods, Joseph F. Iannello

Theses and Dissertations

Perovskite solar cells present the possibility for less expensive electricity generation, through the use of low cost materials and fabrication methods relative to current silicon-based technology. Many current methods of fabricating thin film perovskite solar cells focus on spin-coating, which inherently lacks scalability due to particle conglomeration, poor uniformity over a larger area, and safety concerns. Dip-coating, an alternative to spin-coating, which is explored here addresses these issues which limit scalability. Each individual layer can be separately synthesized, deposited, and characterized, which leads towards scalability. Choosing only the best results from each independent layer allowed progress to the creation of …