Engineering Commons^™

Surface Enabled Lab-On-A-Chip (Loc) Device For Protein Detection And Separation, Zhichao Wang

Dissertations, Master's Theses and Master's Reports

Sensitive and selective chemical/biological detection/analysis for proteins is essential for applications such as disease diagnosis, species phenotype identification, product quality control, and sample examination. Lab-on-a-chip (LOC) device provides advantages of fast analysis, reduced amount of sample requirements, and low cost, to magnificently facilitate protein detection research. Isoelectric focusing (IEF) is a strong and reliable electrophoretic technique capable of discerning proteins from complex mixtures based on the isoelectric point (pI) differences. It has experienced plenty of fruitful developments during previous decades which has given it the capability of performing with highly robust and reproducible analysis. This progress has made IEF devices …

A 3d Biomimetic Scaffold Using Electrospinning For Tissue Engineering Applications, Samerender Nagam Hanumantharao

Dissertations, Master's Theses and Master's Reports

Electrospinning holds great promise for designing functional 3D biomimetic scaffolds for tissue engineering applications. The technique allows for the reproducible fabrication of 3D scaffolds with control over the porosity and thickness. In this work, a novel method for the synthesis of a 3D electroactive scaffold using electrospinning from polycaprolactone (PCL), Polyvinylidene Fluoride (PVDF) and Polyaniline (PANI) is reported. Additional scaffolds involving different morphologies of PCL, PCL-PVDF and PCL-PANI-PVDF were also fabricated and evaluated. The scaffolds were characterized using electron microscopy to visualize the morphologies. Infrared spectroscopy was used to confirm the presence of polymers and their respective phases in the …

A Wireless, Passive Sensor For Measuring Temperature At Orthopedic Implant Sites For Early Diagnosis Of Infections, Salil Sidharthan Karipott

Dissertations, Master's Theses and Master's Reports

Sensorized implants with embedded wireless, passive temperature sensors were developed for early detection of implant-associated infections. The operation principle of the sensor is based on the hypothesis that infections can lead to an increase in local temperature prior to the rise of body temperature. The sensor was an inductive capacitive (LC) circuit that has been used for monitoring of different parameters wirelessly, often in difficult to access environments. The sensor was fabricated on to an interference screw, which is used for tendon and ligament reconstruction surgeries. In this project, a sensorized interference screw was designed and fabricated by accommodating an …

Design Of Robust Hydrogel Based On Mussel-Inspired Chemistry, Yuan Liu

Dissertations, Master's Theses and Master's Reports

The structure of catechol is found in mussel adhesive proteins and contributed to both wet-resistant adhesion and cohesive curing of these proteins. A synthetic nano-silicate, Laponite was incorporated into catechol-containing hydrogels and the hydrogel network-bound catechol formed strong reversible interfacial interaction with Laponite. The contribution of incorporated catechol-Laponite reversible interfacial interactions to the mechanics of hydrogels constructed by different strategies was studied. In the first strategy, Laponite and catechol were introduced into the double network hydrogel (DN) via the free radical co-polymerization of a catechol-containing monomer, backbone monomer, and crosslinker. The introduction of catechol-Laponite interactions significantly improved the compressive strength …

Implantable Wireless Sensor Networks: Application To Measuring Temperature For In Vivo Detection Of Infections, Praharsh Madappaly Veetil

Dissertations, Master's Theses and Master's Reports

It is has been proven that infection in the body cause a local temperature increase due to localized inflammation. Therefore, a method to provide early diagnostic or long-term tracking of this infection will provide great benefits to patients with diabetic foot ulcers or sickle cell disease, and those receiving hemodialysis where they suffer from a weakened immune system. The goal of this project is to develop an implantable wireless temperature sensor based on a wireless sensor network system for monitoring infections in situ. The analog signals from the thermistors are digitized and wirelessly transmitted to a computer with an ez430-rf2500 …

Use Of Lidar In The Design Of Grassed Waterways: Case Study In Agricultural Management In Oklahoma, Annette Sparks

Dissertations, Master's Theses and Master's Reports

Before the advent of Light Detection and Ranging (LiDAR) technology, farm-level infrastructure for sustainable agriculture was designed using topographic maps. LiDAR is a remote sensing method whereby reflected laser pulses are measured to generate high-resolution 3D images of the terrain. This report compares these two methods in the design of grassed waterways for flood drainage and evaluates how the quantitative difference between the two methods can affect the overall hydrologic design. The benefits of LiDAR are expected to be higher accuracy and precision in design, as well as greater reproducibility or consistency, regardless of the designer. To carry out this …

Inhibition Of Bacterial Growth And Prevention Of Bacterial Adhesion With Localized Nitric Oxide Delivery, Julia Osborne

Dissertations, Master's Theses and Master's Reports

Bacterial infections continue to be a problem at the site of an indwelling medical device, and over the years, various bacterial strains have become more resistant to current antibiotic treatments. Bacterial infection at an indwelling medical device can be dangerous and affect the performance of the medical device which can ultimately lead to the failure of the device due to bacterial resistance to treatment.

Nitric Oxide (NO) has been shown to possess antibacterial properties to prevent and inhibit bacterial growth. NO releasing coatings on indwelling medical devices could provide a reduction in bacterial infections that occur at the device site …

Wireless Implantable Magnetoelastic Sensors And Actuators For Biomedical Applications, Andrew Derouin

Dissertations, Master's Theses and Master's Reports

Magnetoelastic sensors represent a low-cost wireless and battery-less method for monitoring parameters in embedded or implanted applications; however, some limitations still exist preventing their commercial implementation. Presented in this work are a variety of studies that are aimed at improving the feasibility of magnetoelastic materials for sensing and actuating applications. Magnetoelastic resonant sensors of non-standard geometries were investigated to determine if geometry could play a role on the sensitivity of the sensor response to mass loading. It was shown that a significant increase in sensitivity could be achieved by using triangular sensors rather than standard rectangular strips. A method for …

Enhancing Osseointegration Of Orthopaedic Implants With Titania Nanotube Surfaces, Erin A. Baker

Dissertations, Master's Theses and Master's Reports

Introduction: As joint arthroplasty surgical procedures increase annually, the development of new strategies, including novel materials and surface modifications, to attain solid bone-implant fixation are needed to increase implant terms of service. In this study, we evaluate two morphologies of titania nanotubes in both in vitro and in vivo experiments to quantify osseointegrative potential and material-level biocompatibility.

Materials and Methods: Samples were prepared via an electrochemical etching process. Two different titania nanotube (TiNT) morphologies were produced, Aligned and Trabecular. For the in vitro experiment, Sprague Dawley (SD) rat marrow-derived bone marrow cells (BMC) were seeded on samples. Alkaline phosphatase (ALP) …

Effects Of Scattering And Absorption On Laser Speckle Contrast Imaging, Kosar Khaksari

Dissertations, Master's Theses and Master's Reports

Laser Speckle Contrast Imaging (LSCI) is a real-time, non-invasive method in used to investigate blood flow and perfusion in biological tissues with high temporal and spatial resolution. A reduction in speckle contrast due to particle motion is the primary contrast mechanism in LSCI. Motion results in speckle fluctuations in time and reduces the contrast over a given camera integration period. There are a variety of parameters that effect contrast besides motion. The optical properties of the scattering medium are one of the parameters effecting LSCI values. Changes in blood hematocrit levels manifest as changes in optical properties. In this work, …

Design And Development Of Optical Elastography Setup, Abhinav Madhavachandran

Dissertations, Master's Theses and Master's Reports

The mechanical properties of the skin are an indication of its physiological condition. The properties can serve as potential information for dermatologists for diagnosis and qualitative assessment. Elastography is a medical imaging modality developed to extract the elastic properties of a tissue by application of an external force. Optical elastography is a technique of elastography which uses laser speckle tracking to study the elastic properties of several soft tissue including skin.

This work is aimed at developing an optical elastography setup that can study the elastic properties of skin. The setup includes an imaging system and a force-application system controlled …

Mechanical Impedance Of Ankle As A Function Of Electromyography Signals Of Lower Leg Muscles Using Artificial Neural Network, Chen Jia

Dissertations, Master's Theses and Master's Reports - Open

This paper reports on the feasibility of developing a model to describe the nonlinear relationship between the mechanical impedance of the human ankle within a specified range of frequency and the root mean square (RMS) value of the Electromyography (EMG) signals of the muscles of human ankle using Artificial Neural Network (ANN). A lower extremity rehabilitation robot — Anklebot was used to apply pseudo-random mechanical perturbations to the ankle and measure the angular displacement of the ankle to estimate the data of ankle mechanical impedance. Meanwhile, the surface EMG signals from the selected muscles were monitored and recorded using a …

Development Of A Cell Morphological Analysis Tool To Evaluate The Ultrasound Vibrational Effects On Cell Adhesion, Joseph M. Smith

Dissertations, Master's Theses and Master's Reports - Open

Fibroblast encapsulation is a stage of the wound healing process in which the implanted device is separated from the biological environment due to the formation of fibrotic tissue. Uncontrolled adhesion of fibroblasts, called fibrosis, has the ability to inhibit an implanted device’s functionality over its lifetime. Over time, fibroblasts have been shown to cause loosening and failure of bone-anchor implants which could include the possibility of harming the patient. The encapsulating process could also hinder the sensitivity of implanted biosensors operating in the body for continuous monitoring. Unfortunately, the antifouling surfaces which are commonly used on implanted devices to control …

Gelatin Microgel Incorporated Poly (Ethylene Glycol) Bioadhesive With Enhanced Adhesive Property And Bioactivity, Yuting Li

Dissertations, Master's Theses and Master's Reports - Open

In this study, chemically crosslinked gelatin microgels were incorporated into dopamine-modified poly (ethylene glycol) (PEGDM) adhesive to form composite bioadhesive with simultaneously improved adhesive property and bioactivity. Gelatin microgel, with an average diameter of 53.6±14.2μm, was prepared with water in oil emulsification method and chemically crosslinked with
1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS). Gelatin microgels were incorporated into PEGDM adhesive precursor solution at 1.5wt%, 3.75wt% and 7.5wt%. The cure time of adhesive reduced from 54 seconds to 37 seconds with increasing gelatin microgel content. Additionally, the incorporation of the gelatin microgel also increased the crosslinking density of the adhesive network …

Ph Responsive, Adhesive Hydrogels Based On Reversible Catechol - Boronic Acid Complexation, Ameya Ravindra Narkar

Dissertations, Master's Theses and Master's Reports - Open

Smart hydrogel adhesives with tunable properties consist of adhesive moieties in the polymer network that respond to external stimuli like pH, temperature, etc. Responsiveness of smart adhesives to pH, in particular, is important because of the simple actuation mechanism and the ability to achieve facile bonding and debonding upon command. Covalently crosslinked hydrogel adhesives were prepared by employing an N-HEAA (hydroxyethyl acrylamide) backbone embedded with dopamine methacrylamide (DMA), a marine mussel inspired adhesive protein and 3-acrylamido phenylboronic acid (AAPBA), to determine the effect of pH on the interfacial binding properties of the hydrogel adhesive with a borosilicate glass substrate. Swelling …

The Influence Of Passive Ankle Joint Power On Balance Recovery, Stephanie E. Hamilton

Dissertations, Master's Theses and Master's Reports - Open

Over one–third of Americans over the age of 65 fall each year, costing more than $19 billion in health care costs in 2000. Many adults 65+ who have not experienced a fall still fear falling, and fear can decrease quality of life and increase the likelihood of falls. Several factors such as muscle strength, power, stiffness and tendon properties change in the human body with age affecting balance, which has been tagged as a fall risk predictor. Additionally, balance recovery strategies also differ between young and older adults, with young adults primarily utilizing their ankle joint and older adults utilizing …

Biocorrosion Rate And Mechanism Of Metallic Magnesium In Model Arterial Environments, Patrick Bowen

Dissertations, Master's Theses and Master's Reports

A new paradigm in biomedical engineering calls for biologically active implants that are absorbed by the body over time. One popular application for this concept is in the engineering of endovascular stents that are delivered concurrently with balloon angioplasty. These devices enable the injured vessels to remain patent during healing, but are not needed for more than a few months after the procedure. Early studies of iron- and magnesium-based stents have concluded that magnesium is a potentially suitable base material for such a device; alloys can achieve acceptable mechanical properties and do not seem to harm the artery during degradation. …

Development Of High Capacity Hyperbranched Nitric Oxide Donors For Controlling Subcutaneous Inflammation, Sean Hopkins

Dissertations, Master's Theses and Master's Reports

Implanted medical devices undergo complications the longer they remain in contact with tissue or blood. This rejection of foreign materials by our body is one of the largest reasons innovations in biomedical sensors and implanted technology are being held back. One means to hold off this unwanted response is through the utilization of nitric oxide (NO) releasing materials. Two unique NO releasing polymeric materials were synthesized and characterized before being implanted subcutaneously. Both NO releasing materials described used S-nitrosothiol (RSNO) chemistry as the main mechanism for NO release. The first material described covalently links an RSNO to the backbone of …

Systematic Study Of The Biological Effects Of Nitric Oxide (No) Using Innovative No Measurement And Delivery Systems, Weilue He

Dissertations, Master's Theses and Master's Reports

Nitric oxide (NO) is recognized as the most important small signaling molecule in the human body. An imbalance of NO is closely associated with many serious diseases such as neurological disorders, cardiovascular diseases, chronic inflammations and cancers. Herein two chemiluminescence-based devices (a real-time NO measurement device and a controllable NO delivery device) were developed to facilitate the NO quantitative study and obtain information for NO related drug design.

The first device used for real-time measuring NO(g) flux from living cells was developed and validated. The principle was to use a two-chamber design, with a cell culture chamber and a gaseous …

Engineering Approaches For Suppressing Deleterious Host Responses To Medical Implants, Connor Mccarthy

Dissertations, Master's Theses and Master's Reports

Small diameter (< 6 mm) vascular grafts suffer from serious deleterious effects not encountered with their larger diameter relatives, leading to premature graft failure through restenosis. Platelet activation, inflammation, and smooth muscle cell proliferation are leading contributors to thrombosis and neointimal hyperplasia, both contributors to the progression of restenosis. It may be possible to suppress negative biological responses to vascular implants through the modification of surface properties and incorporation of drug release into blood contacting materials. In this work, bioengineering approaches are presented to improve the biocompatibility of small diameter vascular grafts.

We demonstrate a novel engineering approach for incorporating natural, decollagenized elastin matrices into PEU 1074A reinforced vascular grafts through spray-coating and electrospinning processes in a manner that retains elastin’s excellent blood contacting properties. A vascular construct with excellent mechanical and surgical handling properties demonstrating the suppression of neointimal hyperplasia is presented after 21 days in vivo.

Nitric oxide (NO) has been investigated over the past several decades due to its platelet, inflammation, and smooth muscle cell suppressing effects; and if appropriately delivered, could positively mediate the contributors to restenosis. Here, we characterize a novel macrocyclic NO …

Integration Of Instrumentation And Processing Software Of A Laser Speckle Contrast Imaging System, Jacob James Carrick

Dissertations, Master's Theses and Master's Reports - Open

Laser speckle contrast imaging (LSCI) has the potential to be a powerful tool in medicine, but more research in the field is required so it can be used properly. To help in the progression of Michigan Tech's research in the field, a graphical user interface (GUI) was designed in Matlab to control the instrumentation of the experiments as well as process the raw speckle images into contrast images while they are being acquired. The design of the system was successful and is currently being used by Michigan Tech's Biomedical Engineering department. This thesis describes the development of the LSCI GUI …

Design And Application Of Wireless Passive Magnetoelastic Resonance And Magnetoharmonic Force Sensors, Brandon D. Pereles

Dissertations, Master's Theses and Master's Reports - Open

The objective of the work described in this dissertation is the development of new wireless passive force monitoring platforms for applications in the medical field, specifically monitoring lower limb prosthetics. The developed sensors consist of stress sensitive, magnetically soft amorphous metallic glass materials. The first technology is based on magnetoelastic resonance. Specifically, when exposed to an AC excitation field along with a constant DC bias field, the magnetoelastic material mechanically vibrates, and may reaches resonance if the field frequency matches the mechanical resonant frequency of the material. The presented work illustrates that an applied loading pins portions of the strip, …

Utilizing Dielectrophoresis To Determine The Physiological Differences Of Eukaryotic Cells, Tayloria Nicole Gail Adams

Dissertations, Master's Theses and Master's Reports - Open

Type 1 diabetes affects over 108,000 children, and this number is steadily increasing. Current insulin therapies help manage the disease but are not a cure. Over a child’s lifetime they can develop kidney disease, blindness, cardiovascular disease and many other issues due to the complications of type 1 diabetes. This autoimmune disease destroys beta cells located in the pancreas, which are used to regulate glucose levels in the body. Because there is no cure and many children are affected by the disease there is a need for alternative therapeutic options that can lead to a cure.

Human mesenchymal stem cells …

A Backing Device Based On An Embedded Stiffener And Retractable Insertion Tool For Thin-Film Cochlear Arrays, Radheshyam Tewari

Dissertations, Master's Theses and Master's Reports - Open

Intracochlear trauma from surgical insertion of bulky electrode arrays and inadequate pitch perception are areas of concern with current hand-assembled commercial cochlear implants. Parylene thin-film arrays with higher electrode densities and lower profiles are a potential solution, but lack rigidity and hence depend on manually fabricated permanently attached polyethylene terephthalate (PET) tubing based bulky backing devices. As a solution, we investigated a new backing device with two sub-systems. The first sub-system is a thin poly(lactic acid) (PLA) stiffener that will be embedded in the parylene array. The second sub-system is an attaching and detaching mechanism, utilizing a poly(N-vinylpyrrolidone)-block-poly(d,l-lactide) (PVP-b-PDLLA) copolymer-based …

Fabrication Of Drug Eluting Ti Implants For Dental/Orthopedic Applications, Azhang Hamlekhan

Dissertations, Master's Theses and Master's Reports - Open

Titanium and its alloys are typically used for fabrication of dental and orthopedic implants as they possess various desirable properties including biocompatibility and corrosion resistance. In spite of such benefits, titanium implants show lack of osseointegration after surgery in minor cases. The objective of this research has been to modify the surface of titanium alloy for medical applications through increasing surface hydrophilicity and drug loading. Primarily, anodization method is employed for fabrication of nanotubes on titanium surface to act as anchoring cite for cells.

Considering the key role of surface hydrophilicity on cellular attachment to the surface and subsequent biological …

Development Of Vapor Deposited Silica Sol-Gel Particles For A Bioactive Materials System To Direct Osteoblast Behavior, Katherine Lynn Snyder

Dissertations, Master's Theses and Master's Reports - Open

Tissue engineering and regenerative medicine have emerged in an effort to generate replacement tissues capable of restoring native tissue structure and function, but because of the complexity of biologic system, this has proven to be much harder than originally anticipated. Silica based bioactive glasses are popular as biomaterials because of their ability to enhance osteogenesis and angiogenesis. Sol-gel processing methods are popular in generating these materials because it offers: 1) mild processing conditions; 2) easily controlled structure and composition; 3) the ability to incorporate biological molecules; and 4) inherent biocompatibility. The goal of this work was to develop a bioactive …

Studies Of Functionalized Nanoparticles For Smart Self-Assembly And As Controlled Drug Delivery, Xiaochu Ding

Dissertations, Master's Theses and Master's Reports - Open

This dissertation is related to the studies of functionalized nanoparticles for self-assembly and as controlled drug delivery system. The whole topic is composed of two parts. In the first part, the research was conducted to design and synthesize a new type of ionic peptide-functionalized copolymer conjugates for self-assembly into nanoparticle fibers and 3D scaffolds with the ability of multi-drug loading and governing the release rate of each drug for tissue engineering. The self-assembly study confirmed that such peptide-functionalized amphiphilic copolymers underwent different self-assembly behavior. The bigger nanoparticles were more easily assembled into nanoparticle fibers and 3D scaffolds with larger pore …

Alternating Current Dielectrophoretic Manipulation Of Erythrocytes In Medical Microdevice Technology, Kaela M. Leonard

Dissertations, Master's Theses and Master's Reports - Open

Medical microdevices have gained popularity in the past few decades because they allow the medical laboratory to be taken out into the field and for disease diagnostics to happen with a smaller sample volume, at a lower cost and much faster. Blood is the human body's most readily available and informative diagnostic fluid because of the wealth of information it provides about the body's general health including enzymatic, proteomic and immunological states. The purpose of this project is to optimize operating conditions and study ABO-Rh erythrocytes dielectrophoretic responses to alternating current electric signals. The end goal of this project is …

Exploration Of The Role Of Serum Factors In Maintaining Bone Mass During Hibernation In Black Bears, Rachel Marie Bradford

Dissertations, Master's Theses and Master's Reports - Open

Disuse osteoporosis is a condition in which reduced mechanical loading (e.g. bed-rest, immobilization, or paralysis) results in unbalanced bone turnover. The American black bear is a unique, naturally occurring model for the prevention of disuse osteoporosis. Bears remain mostly inactive for up to half a year of hibernation annually, yet they do not lose bone mechanical strength or structural properties throughout hibernation. The long-term goal of this study is to determine the biological mechanism through which bears maintain bone during hibernation. This mechanism could pinpoint new signaling pathway targets for the development of drugs for osteoporosis prevention. In this study, …

Use Of A 3d Perfusion Bioreactor With Osteoblasts And Osteoblast/Endothelial Cell Co-Cultures To Improve Tissue-Engineered Bone, Matthew J. Barron

Dissertations, Master's Theses and Master's Reports - Open

The delivery of oxygen, nutrients, and the removal of waste are essential for cellular survival. Culture systems for 3D bone tissue engineering have addressed this issue by utilizing perfusion flow bioreactors that stimulate osteogenic activity through the delivery of oxygen and nutrients by low-shear fluid flow. It is also well established that bone responds to mechanical stimulation, but may desensitize under continuous loading. While perfusion flow and mechanical stimulation are used to increase cellular survival in vitro, 3D tissue-engineered constructs face additional limitations upon in vivo implantation. As it requires significant amounts of time for vascular infiltration by the host, …