Digital Commons Network^™

Nanostructured Apatite-Mullite Glass-Ceramics For Enhanced Primary Human Osteoblast Cell Response, Gordon Cooke, Conor Dunne, Sarah Keane, Daithi De Faoite, Seamas Donnelly, Kenneth Stanton

Articles

This work investigates the difference in viability of primary human foetal osteoblast cells on a glass-ceramic surface with nanoscale topography relative to viability on a smooth glass-ceramic surface containing a bioactive phase. Apatite-mullite glass-ceramics containing bioactive fluorapatite (Ca₁₀(PO₄)₆F₂) and bioinert mullite (Si₂Al₆O₁₃) were synthesised and subsequent heat-treatment was optimised to form nano-sized fluorapatite crystals. Etching was used to selectively remove the bioactive phase, producing a surface with disordered nanoscale topography. Cells were seeded onto a smooth polished glass-ceramic substrate with the bioactive phase intact, an etched …

Additive Manufacturing Techniques And Their Biomedical Applications, Yujing Liu, Wei Wang, Laichang Zhang

Research outputs 2014 to 2021

Additive manufacturing (AM), also known as three-dimensional (3D) printing, is gaining increasing attention in medical fields, especially in dental and implant areas. Because AM technologies have many advantages in comparison with traditional technologies, such as the ability to manufacture patient-specific complex components, high material utilization, support of tissue growth, and a unique customized service for individual patients, AM is considered to have a large potential market in medical fields. This brief review presents the recent progress of 3D-printed ­biomedical materials for bone applications, mainly for metallic materials, including multifunctional alloys with high strength and low Young’s modulus, shape memory alloys, …

Fabricating Zirconia Parts With Organic Support Material By The Ceramic On-Demand Extrusion Process, Wenbin Li, Amir Ghazanfari, Devin Mcmillen, Andrew Scherff, Ming-Chuan Leu, Greg Hilmas

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Ceramic On-Demand Extrusion (CODE) is an extrusion-based additive manufacturing process recently developed for fabricating dense, functional ceramic components. This paper presents a further development of this process and focuses on fabricating 3 mol% yttria-stabilized zirconia (3YSZ) components that cannot be fabricated without using support structures. The 3YSZ paste is deposited through the main nozzle, and a polycaprolactone (PCL) pellet feedstock is melted and deposited through an auxiliary nozzle to build support structures. After a green part is printed and dried, the support structures are removed by heating the part to ~70 ⁰C to melt the PCL. The part is then …

Design And Fabrication Of Functionally Graded Material From Ti To Γ-Tial By Laser Metal Deposition, Xueyang Chen, Lei Yan, Joseph William Newkirk, Frank W. Liou

Materials Science and Engineering Faculty Research & Creative Works

Functionally graded material (FGM) is one kind of advanced material characterized by a gradual change in properties as the position varies. The spatial variation of compositional and microstructure over volume is aimed to control corresponding functional properties. In this research, when 100% γ-TiAl was directly deposited on pure Ti substrate, cracks were formed within the γ-TiAl layer. Then a six-layer crack-free functionally graded material of Ti/TiAl was designed and fabricated by laser metal deposition (LMD) method, with composition changing from pure Ti on one side to 100% γ-TiAl on the other side. The fabricated FGM was characterized for material properties …

Fabricating Zirconia Components With Organic Support Material By The Ceramic On-Demand Extrusion Process, Wenbin Li, Amir Ghazanfari, Devin Mcmillen, Andrew Scherff, Ming-Chuan Leu, Greg Hilmas

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Ceramic On-Demand Extrusion (CODE) is an extrusion-based additive manufacturing process recently developed for fabricating dense, functional ceramic components. This paper presents a further development of this process and focuses on fabricating 3 mol% yttria-stabilized zirconia (3YSZ) components that cannot be fabricated without using support structures. The 3YSZ paste is deposited through the main nozzle, and a polycaprolactone (PCL) pellet feedstock is melted and deposited through an auxiliary nozzle to build support structures. After a green part is printed and dried, the support structures are removed by heating the part to ~70°C to melt the PCL. The part is then sintered …

Phase Separation In Ti-6al-4v Alloys With Boron Additions For Biomedical Applications: Scanning Kelvin Probe Force Microscopy Investigation Of Microgalvanic Couples And Corrosion Initiation, P. H. Davis, K. Robles, K. Livingston, S. Johns, V. A. Ravi, E. Graugnard, M. F. Hurley

Materials Science and Engineering Faculty Publications and Presentations

To investigate the effect of boron additions on the corrosion behavior of Ti-6Al-4V for potential use in biomedical implants and devices, cast samples of Ti-6Al-4V were alloyed with 0.01% to 1.09% boron by weight and subjected to hot isostatic pressing. Subsequent analysis via scanning Kelvin probe force microscopy and scanning electron microscopy/energy-dispersive spectroscopy revealed the presence of both alpha (α) and beta (β) phase titanium, enriched in aluminum and vanadium, respectively. At all concentrations, boron additions affected the grain structure and were dispersed throughout both phases, but above the solubility limit, needle-like TiB structures also formed. …

The Effect Of Magnification Loupes On Dental Hygienists' Posture While Exploring, Emily Ludwig, Gayle B. Mccombs, Susan L. Tolle, Daniel M. Russell

Dental Hygiene Faculty Publications

Purpose: The purpose of this study was to determine the effects of dental magnification loupes on posture during instrumentation.

Methods: A convenience sample of 27 right-handed dental hygienists, with no prior history of injuries or disabilities of the head, neck, or trunk region, enrolled in the study. Baseline posture calibration was taken and tri-axial accelerometers were placed on four locations of the head and trunk (occipital region of head; cervical vertebrae C5; thoracic vertebrae T5; lumbar vertebrae L1) to measure acceleration and the orientation of the body to gravity. Participants were randomly assigned to wear self-supplied magnification loupes during either …

Maximizing Operating Room Performance Using Portfolio Selection, Vivek Reddy Gunna, Amin Abedini, Wei Li

Mechanical Engineering Faculty Publications

The operating room (OR) is responsible for most hospital admissions and is one of the most cost and work intensive areas in the hospital. From recent trends, we observe an ironic parallel increase among expenditure and waiting time. Therefore, improving OR scheduling has become obligatory, particularly in terms of patient flow and benefit. Most of the hospitals rely on average patient arrivals and processing times in OR planning. But in practice, variations in arrivals and processing times causes high instability in OR performance. Our model of optimization provides OR schedules maximizing patient flow and benefit at a fixed level of …

Novel Layered Double Hydroxides-Hydroxyapatite/Gelatin Bone Tissue Engineering Scaffolds: Fabrication, Characterization, And In Vivo Study, Fateme Fayyazbakhsh, Mehran Solati-Hashjin, Abbas Keshtkar, Mohammad Ali Shokrgozar, Mohammad Mehdi Dehghan, Bagher Larijani

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Developing Porous Biodegradable Scaffolds through Simple Methods is One of the Main Approaches of Bone Tissue Engineering (BTE). in This Work, a Novel BTE Composite Containing Layered Double Hydroxides (LDH), Hydroxyapatite (HA) and Gelatin (GEL) Was Fabricated using Co-Precipitation and Solvent-Casting Methods. Physiochemical Characterizations Showed that the Chemical Composition and Microstructure of the Scaffolds Were Similar to the Natural Spongy Bone. Interconnected Macropores Ranging over 100 to 600 Μm Were Observed for Both Scaffolds While the Porosity of 90 ± 0.12% and 92.11 ± 0.15%, as Well As, Young's Modulus of 19.8 ± 0.41 and 12.5 ± 0.35 GPa Were …

Perspective: The Physics, Diagnostics, And Applications Of Atmospheric Pressure Low Temperature Plasma Sources Used In Plasma Medicine, M. Laroussi

Electrical & Computer Engineering Faculty Publications

Low temperature plasmas have been used in various plasma processing applications for several decades. But it is only in the last thirty years or so that sources generating such plasmas at atmospheric pressure in reliable and stable ways have become more prevalent. First, in the late 1980s, the dielectric barrier discharge was used to generate relatively large volume diffuse plasmas at atmospheric pressure. Then, in the early 2000s, plasma jets that can launch cold plasma plumes in ambient air were developed. Extensive experimental and modeling work was carried out on both methods and much of the physics governing such sources …

Establishment Of Innovative Shared Departments To Advance Interdisciplinary Education, Ronald S. Harichandran, Brian Kench, Summer Mcgee, Michael A. Collura, Jean Nocito-Gobel, Charles David Skipton

Engineering and Applied Science Education Faculty Publications

More and more universities are pursuing interdisciplinary academic activities that span across department and college boundaries. Administrative structures to facilitate such programs are difficult to establish within traditional university frameworks consisting of disciplinary departments and colleges. Often interdisciplinary programs are housed in a traditional disciplinary department or college, or in a standalone center reporting to a college dean or the provost. The difficulty of these structures is obtaining broad buy-in from faculty across departments and having disciplinary degree programs include interdisciplinary coursework.

To overcome the difficulties described above, an innovative shared department structure that fosters collaborations to advance interdisciplinary education …

Development Of Novel, Microscale Fracture Toughness Testing For Adhesives, Dillon S. Watring

FIU Electronic Theses and Dissertations

The purpose of this thesis was to develop microscale fracture toughness tests to be performed in situ based off previously used macroscale fracture toughness tests. The thesis also was to use these tests to perform in situ analysis and imaging of reinforced adhesives during crack propagation. Two different fracture toughness tests were developed for this thesis through developing fixtures and sample geometry. A microscale double cantilever beam (DCB) test was developed for mode I fracture (opening mode). A microscale end notch flexure (ENF) test was developed for mode II fracture (sliding mode).

Three different types of materials were used as …

A Novel Micro Cold Atmospheric Plasma Device For Glioblastoma Both In Vitro And In Vivo., Zhitong Chen, Hayk Simonyan, Xiaoqian Cheng, Eda Gjika, Li Lin, Jerome Canady, Jonathan H Sherman, Colin Young, Michael Keidar

Pharmacology and Physiology Faculty Publications

: Cold atmospheric plasma (CAP) treatment is a rapidly expanding and emerging technology for cancer treatment. Direct CAP jet irradiation is limited to the skin and it can also be invoked as a supplement therapy during surgery as it only causes cell death in the upper three to five cell layers. However, the current cannulas from which the plasma emanates are too large for intracranial applications. To enhance efficiency and expand the applicability of the CAP method for brain tumors and reduce the gas flow rate and size of the plasma jet, a novel micro-sized CAP device (µCAP) was developed …

Common Treatments And Procedures Used For Fractures Of The Distal Radius And Scaphoid: A Review, Basel A. Khader, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The distal radius and the scaphoid are the most commonly injured carpal bones among both active adults and the osteoporotic elderly. The purpose of surgical treatment is to restore form and function to the wrist. Depending on the nature of the fracture, either topical procedures or invasive surgery can be applied. This article critiques the treatments currently used for fixation of wrist fractures in order to drive the development of new materials to improve patient outcomes.

Chitosan Nanoparticle Modifications For Improved Gene Delivery In An Oral Dna Vaccine Application, Austin Helmink

Honors Theses

Vaccines represent one of the most significant medical innovations of the 20^th century, resulting in the eradication or near eradication of a handful of deadly diseases. However, many infectious diseases remain resistant to effective vaccination, largely due to a lack full immune activation by traditional protein-based vaccines. A promising alternative vaccination strategy is the emerging development of DNA vaccines, which rely upon the delivery of exogenous genetic material to host cells encoding for a viral or bacterial antigen in order to induce a robust immune response by closely mimicking live infection. The delivery of genetic material requires a carrier …

A Novel Tantalum-Containing Bioglass. Part Ii. Development Of A Bioadhesive For Sternal Fixation And Repair, Adel Mf Alhalawani, Cina Mehrvar, Wendy Stone, Stephen D. Waldman, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

With over a million median sternotomy surgeries performed worldwide every year, sternal wound complications have posed a serious risk to the affected patients. A rigid therapeutic sternal fixation device has therefore become a necessity. In this work, the incorporation of up to 0.5 mol% of tantalum pentoxide (Ta₂O₅), in exchange for zinc oxide (ZnO), into the SiO₂-ZnO-CaO-SrO-P₂O₅ glass system is presented. The effect of Ta incorporation on the physical, chemical and biological properties of the glass polyalkenoate cements (GPCs) prepared from them have been presented in this manuscript. The data obtained …

Simultaneous Measurement Of Refractive Index And Thickness Of Multilayer Systems Using Fourier Domain Optical Coherence Tomography, Part 2: Implementation, Payman Rajai

Mechanical, Automotive & Materials Engineering Publications

We introduce a theoretical method for simultaneous measurement of refractive index and thickness of multilayer systems using Fourier domain optical coherence tomography (FD-OCT) without any auxiliary arrangement. The input data to the formalism are the FD-OCT measured optical path lengths (OPLs) and properly selected spectral components of FD-OCT interference spectrum. The outputs of the formalism can be affected significantly by uncertainty in measuring the OPLs. An optimization method is introduced to deal with the relatively large amount of uncertainty in measured OPLs and enhance the final results. Simulation result shows that by using the optimization method, indices can be extracted …

Simultaneous Measurement Of Refractive Index And Thickness Of Multilayer Systems Using Fourier Domain Optical Coherence Tomography, Part 1: Theory, Payman Rajai

Mechanical, Automotive & Materials Engineering Publications

We introduce a theoretical framework for simultaneous refractive index and thickness measurement of multilayer systems using the Fourier domain optical coherence tomography (FD-OCT) system without any previous information about the item under investigation. The input data to the new formalism are the FD-OCT measured optical path lengths and properly selected spectral components of the FD-OCT interference spectrum. No additional arrangement, reference reflector, or mechanical scanning is needed in this approach. Simulation results show that the accuracy of the extracted parameters depends on the index contrast of the sample while it is insensitive to the sample’s thickness profile. For transparent biological …

Modeling Of Selective Laser Sintering/ Selective Laser Melting, Xuan Wang, Connor West

Industrial and Manufacturing Engineering

Selective laser sintering and selective laser melting are powder based additive manufacturing (AM) process that can rapidly manufacture parts with comparable mechanical properties to conventional manufacturing methods directly from digital files. However, the processing recipe development and design optimization of AM parts are often based on trial and error which erodes the benefit of AM. Modeling is a powerful tool to enable faster development cycle by significantly reducing the experimental efforts. In this paper we discussed the current status of selective laser sintering/melting modeling, in which the laser and powder interaction was studied to understand and predict the process and …

Level Anticrossing Of Impurity States In Semiconductor Nanocrystals, Anvar S. Baimuratov, Ivan D. Rukhlenko, Vadim K. Turkov, Irina Ponomareva, Mikhail Yu Leonov, Tatiana S. Perova, Kevin Berwick, Alexander V. Baranov, Anatoly V. Federov

Articles

The size dependence of the quantized energies of elementary excitations is an essential feature of quantum nanostructures, underlying most of their applications in science and technology. Here we report on a fundamental property of impurity states in semiconductor nanocrystals that appears to have been overlooked—the anticrossing of energy levels exhibiting different size dependencies. We show that this property is inherent to the energy spectra of charge carriers whose spatial motion is simultaneously affected by the Coulomb potential of the impurity ion and the confining potential of the nanocrystal. The coupling of impurity states, which leads to the anticrossing, can be …

Substrate Stiffness Controls Osteoblastic And Chondrocytic Differentiation Of Mesenchymal Stem Cells Without Exogenous Stimuli, Rene Olivares-Navarrete, Erin M. Lee, Kathryn Smith, Sharon L. Hyzy, Maryam Doroudi, Joseph K. Williams, Ken Gall, Barbara D. Boyan, Zvi Schwartz

Biomedical Engineering Publications

Stem cell fate has been linked to the mechanical properties of their underlying substrate, affecting mechanoreceptors and ultimately leading to downstream biological response. Studies have used polymers to mimic the stiffness of extracellular matrix as well as of individual tissues and shown mesenchymal stem cells (MSCs) could be directed along specific lineages. In this study, we examined the role of stiffness in MSC differentiation to two closely related cell phenotypes: osteoblast and chondrocyte. We prepared four methyl acrylate/methyl methacrylate (MA/MMA) polymer surfaces with elastic moduli ranging from 0.1 MPa to 310 MPa by altering monomer concentration. MSCs were cultured in …

Influence Of Small Particles Inclusion On Selective Laser Melting Of Ti-6al-4v Powder, Haijun Gong, J. J.S. Dilip, Li Yang, Chong Teng, Brent Stucker

Department of Manufacturing Engineering Faculty Research and Publications

The particle size distribution and powder morphology of metallic powders have an important effect on powder bed fusion based additive manufacturing processes, such as selective laser melting (SLM). The process development and parameter optimization require a fundamental understanding of the influence of powder on SLM. This study introduces a pre-alloyed titanium alloy Ti-6Al-4V powder, which has a certain amount of small particles, for SLM. The influence of small particle inclusion is investigated through microscopy of surface topography, elemental and microstructural analysis, and mechanical testing, compared to the Ti-6Al-4V powder provided by SLM machine vendor. It is found that the small …

Incorporation Of Glass-Reinforced Hydroxyapatite Microparticles Into Poly(Lactic Acid) Electrospun Fibre Mats For Biomedical Applications, Daniel Santos, Cristina Correia, D M. Silva, P S. Gomes, M H. Fernandes, J D. Santos, Vitor Sencadas

Faculty of Engineering and Information Sciences - Papers: Part B

Tissue engineering is constantly evolving towards novel materials that mimic the properties of the replaced injured tissue or organ. A hybrid electrospun membrane of electroactive poly(l-acid lactic) (PLLA) polymer with glass reinforced hydroxyapatite (Bonelike®) microparticles placed among the polymer fibres in a morphology like "islands in the sea" was processed. The incorporation of 60 to 80 wt% Bonelike® bone grafts granules with ≤ 150 μm into the polymer solution lead to an amorphous polymeric fibre membranes, and a decrease of the average polymer fibre diameter from 550 ± 150 nm for neat PLA down to 440 ± 170 nm for …

Error Aggregation In The Reengineering Process From 3d Scanning To Printing, Jennifer G. Michaeli, Matthew C. Degroff, Roman C. Roxas

Engineering Technology Faculty Publications

This work aims to study the aggregation of dimensional errors in the reengineering processes using 3D scanning and printing without initial design drawings. A 57-tooth spur gear is used as an example to facilitate the discussion. Two approaches are investigated. The first one builds the gear model based upon measurement taken from a caliper, and the second approach uses a 3D scanner to collect geometry data. Dimensional errors in each stage of these two approaches are investigated. Particular attention is paid to the geometry data flow in the reengineering process from data acquisition and editing to model construction. Recommendations are …

Growth Mechanisms Of Multiscale, Mound-Like Surface Structures On Titanium By Femtosecond Laser Processing, Edwin Peng, Ryan Bell, Craig A. Zuhlke, Meiyu Wang, Dennis R. Alexander, George Gogos, Jeffrey E. Shield

Department of Mechanical and Materials Engineering: Faculty Publications

Femtosecond laser surface processing (FLSP) can be used to functionalize many surfaces, imparting specialized properties such as increased broadband optical absorption or superhydrophobicity/-hydrophilicity. In this study, the subsurface microstructure of a series of mound-like FLSP structures formed on commercially pure titanium using five combinations of laser fluence and cumulative pulse counts was studied. Using a dual beam Scanning Electron Microscope with a Focused Ion Beam, the subsurface microstructure for each FLSP structure type was revealed by cross-sectioning. The microstructure of the mounds formed using the lowest fluence value consists of the original Ti grains. This is evidence that preferential laser …

3d Printing Aids Acetabular Reconstruction In Complex Revision Hip Arthroplasty, Andrew J. Hughes, Cathal Debuitleir, Philip Soden, Brian O'Donnchada, Anthony Tansey, Ali Abdulkarim, Colm Mcmahon, Conor J. Hurson

Articles

Revision hip arthroplasty requires comprehensive appreciation of abnormal bony anatomy. Advances in radiology and manufacturing technology have made three-dimensional (3D) representation of osseous anatomy obtainable, which provide visual and tactile feedback. Such life-size 3D models were manufactured from computed tomography scans of three hip joints in two patients. The first patient had undergone multiple previous hip arthroplasties for bilateral hip infections, resulting in right-sided pelvic discontinuity and a severe left-sided posterosuperior acetabular deficiency. The second patient had a first-stage revision for infection and recurrent dislocations. Specific metal reduction protocols were used to reduce artefact. The images were imported into Materialise …

Growth Mechanisms Of Multiscale, Mound-Like Surface Structures On Titanium By Femtosecond Laser Processing, Edwin Peng, Ryan Bell, Craig A. Zuhlke, Meiyu Wang, Dennis R. Alexander, George Gogos, Jeffrey E. Shield

Department of Mechanical and Materials Engineering: Faculty Publications

Femtosecond laser surface processing (FLSP) can be used to functionalize many surfaces, imparting specialized properties such as increased broadband optical absorption or superhydrophobicity/- hydrophilicity. In this study, the subsurface microstructure of a series of mound-like FLSP structures formed on commercially pure titanium using five combinations of laser fluence and cumulative pulse counts was studied. Using a dual beam Scanning Electron Microscope with a Focused Ion Beam, the subsurface microstructure for each FLSP structure type was revealed by cross-sectioning. The microstructure of the mounds formed using the lowest fluence value consists of the original Ti grains. This is evidence that preferential …

Lessons Learned From A 10-Year Collaboration Between Biomedical Engineering And Industrial Design Students In Capstone Design Projects, Jay R. Goldberg, Pascal Malassigné

Biomedical Engineering Faculty Research and Publications

Engineers and industrial designers have different approaches to problem solving. Both place heavy emphasis on identification of customer needs, manufacturing methods, and prototyping. Industrial designers focus on aesthetics, ergonomics, ease of use, manufacturing methods, and the user’s experience. They tend to be more visual and more concerned with the interaction between users and products. Engineers focus on functionality, performance requirements, analytical modeling, and design verification and validation. They tend to be more analytical and more concerned with the design of internal components and product performance. Engineers and industrial designers often work together on project teams in industry. Collaboration between the …

Contributions Of Secondary Fragmentation By Carbon Ion Beams In Water Phantom: Monte Carlo Simulation, C Ying, David Bolst, Linh T. Tran, Susanna Guatelli, Anatoly B. Rosenfeld, W Kamil

Faculty of Engineering and Information Sciences - Papers: Part B

Heavy-particle therapy such as carbon ion therapy is currently very popular because of its superior conformality in terms of dose distribution and higher Relative Biological Effectiveness (RBE). However, carbon ion beams produce a complex mixed radiation field, which needs to be fully characterised. In this study, the fragmentation of a 290 MeV/u primary carbon ion beam was studied using the Geant4 Monte Carlo Toolkit. When the primary carbon ion beam interacts with water, secondary light charged particles (H, He, Li, Be, B) and fast neutrons are produced, contributing to the dose, especially after the distal edge of the Bragg peak.

Electrically Stimulated Adipose Stem Cells On Polypyrrole-Coated Scaffolds For Smooth Muscle Tissue Engineering, Miina M. Bjorninen, Kerry J. Gilmore, Jani M. Pelto, Riitta Seppanen-Kaijansinkko, Minna Kellomaki, Susanna S. Miettinen, Gordon G. Wallace, Dirk Grijpma, Suvi P. Haimi

Australian Institute for Innovative Materials - Papers

We investigated the use of polypyrrole (PPy)-coated polymer scaffolds and electrical stimulation (ES) to differentiate adipose stem cells (ASCs) towards smooth muscle cells (SMCs). Since tissue engineering lacks robust and reusable 3D ES devices we developed a device that can deliver ES in a reliable, repeatable, and cost-efficient way in a 3D environment. Long pulse (1 ms) or short pulse (0.25 ms) biphasic electric current at a frequency of 10 Hz was applied to ASCs to study the effects of ES on ASC viability and differentiation towards SMCs on the PPy-coated scaffolds. PPy-coated scaffolds promoted proliferation and induced stronger calponin, …