Mechanical Engineering Commons^™

Atomic Force Microscopy Based Dna Sensing And Manipulation, Matthew Shubert

Mechanical Engineering Undergraduate Honors Theses

Sequencing DNA provides a positive impact for the biomedical community by understanding a wide variety of applications such as human genetics, disease, and pathogens. The reason the Arkansas Micro & Nano Systems lab is involved with research in DNA sequencing is due to the current, leading industry method. Nanopore sequencing was developed by Oxford Nanopore Technology in which its sequencing method separates double stranded DNA to electrically characterize individual nucleotides traveling through a charged nanopore. Unfortunately, nanopore sequencing uses biological materials that require a shelf life and drives high cost. Therefore, the Arkansas Micro & Nano Systems lab has developed …

Influence Of Extracellular Matrix Stiffness And Topography On Neuronal Cell Behavior And Neurite Outgrowth, Mohan Yasodharababu

Graduate Theses and Dissertations

The focus of regeneration therapy for traumatic brain injuries and Alzheimer's disease is on the promotion and growth of neuronal cells. In vitro research attempts to improve this by modifying the stiffness and topography of the extracellular matrix (ECM). However, the limitations of in vitro experiments make it difficult to control the individual factors influencing neuronal cell growth. A computational model can be used to decouple individual factors and study them individually to gain a better understanding of the mechanics between the neuronal cell and ECM, which will aid in the design of in vitro experimental studies.

This study develops …

Performance And Economics Of Solar Inverters And Module Level Power Electronics In A 1 Mw Photovoltaic System, Maxwell Criswell

Biological and Agricultural Engineering Undergraduate Honors Theses

Photovoltaic solar panels convert sunlight to electricity in the form of direct current; therefore, a necessary component of every photovoltaic system is an inverter to convert the electricity to usable alternating current. There are various commercially available inverter technologies manufactured today such as microinverters, string inverters, and central inverters, as well as module level power electronic devices such as DC optimizers that are capable of improving system performance in string and central inverter systems. This thesis compares the performance and economics of five different inverter and module level power electronic systems through model simulation using Helioscope software. The five alternatives …

Design And Control Of A Peristaltic Pump To Simulate Left Atrial Pressure In A Conductive Silicone Model, Jeremy Collins

Mechanical Engineering Undergraduate Honors Theses

According to the CDC, atrial fibrillation is responsible for more than 454,000 hospitalizations and approximately 158,000 deaths per year. A common treatment for atrial fibrillation is catheter ablation, a process in which a long flexible tube is guided through the femoral artery and to the source of arrhythmia in the heart, where it measures the electrical potential at various locations and converts problematic heart tissue to scar tissue via ablation. This paper details the design and control of a low-cost ($400) peristaltic pump system using repetitive control to replicate blood pressure in the left atrium in a conductive silicone model …

3d Printing A Microfluidic Chip Capable Of Droplet Emulsion Using Ninjaflex Filament, Robert Andrews

Mechanical Engineering Undergraduate Honors Theses

This paper details an investigation into methods and designs of 3D printing a microfluidic system capable of droplet emulsion using NinjaFlex filament. The specific field in which this paper’s experiment is rooted is dubbed “BioMEMS,” short for bio microelectromechanical systems. One prominent research area in BioMEMS is developing a “lab on a chip.” Essentially, the goal is to miniaturize common lab processes to the micro scale, rendering it possible to include these processes in a small chip. Reducing necessary sample sizes, shortening the reaction times of lab processes, and increasing mobility of lab processes can all be realized through microfluidic …

Methods To Remotely Eliminate Biofilm From Medical Implants Using 2.4 Ghz Microwaves, Brett Glenn

Mechanical Engineering Undergraduate Honors Theses

Infections associated with biofilm growth are usually challenging to eradicate due to their high tolerance toward antibiotics [11, 12]. Biofilms often form on the inert surfaces of medically implanted devices [13]. No matter the sophistication, microbial infections can develop on all medical devices and tissue engineering constructs [12]. Related infections lead to 2 million cases annually in the U.S., costing the healthcare system over $5 billion in additional healthcare expenses [12].

Novel solutions to biofilm’s microbial colonization span the spectrum of engineering and science disciplines. Yet a practical solution still does not exist. The research presented here will explore a …

Effects Of Hydration And Mineralization On The Mechanical Behavior Of Collagen Fibrils, Marco Fielder

Graduate Theses and Dissertations

Bone is a composite biomaterial with a structural load-bearing function. Understanding the biomechanics of bone is important for characterizing factors such as age, trauma, or disease, and in the development of scaffolds for tissue engineering and bioinspired materials. At the nanoscale, bone is primarily composed of collagen protein, apatite crystals, and water. Though several studies have characterized nanoscale bone mechanics as the mineral content changes, the effect of water, mineral, and carbon nanotube (CNT) content and distribution in fibril gap and overlap regions is unexplored. This study used molecular dynamics to investigate the change in collagen fibril deformation mechanisms as …

Blood-Brain Barrier-On-A-Chip Systems Based On 3d Printing, Cade I. Harding

Mechanical Engineering Undergraduate Honors Theses

This research focused on the design and testing of a blood-brain barrier (BBB)-on-a-chip microfluidic device produced using 3D printing. First, COMSOL simulations were used to define dimensions of the microchannel that would most accurately replicate the flow environment imposed on the blood-brain barrier, the wall shear stress being the most important characteristic. In using COMSOL, water was used as the simulated fluid and also the testing fluid in the fabricated devices. Therefore, the microsystem is designed to produce the BBB environment using water instead of blood. The numerical simulation parameters were based on theoretical calculations performed to scale up the …

Atomic Force Microscopy Based Dna Analysis, Drew Creighton

Mechanical Engineering Undergraduate Honors Theses

This report explores dry and wet scanning of a surface and DNA pickup using an AFM, as well as fluorescent staining of DNA. Dry and wet scans of DNA were obtained using a cantilever AFM tip in tapping mode. Dry scans were found to be clearer than wet scans; however, the drying process was found to decrease the thickness of DNA 2–4 times less than its original thickness. Alternately, wet scans were found to be less clear than dry scans and introduced more noise into the images obtained. Additionally, DNA kept its initial thickness during wet scanning. DNA was capable …