Biomedical Engineering and Bioengineering Commons^™

Optimized 3d-Printing Of Carbon Fiber-Reinforced Polyether-Ether-Ketone (Cfr-Peek) For Use In Overmolded Lattice Composite, Ryan C. Ogle

Masters Theses

Current orthopedic implants are overwhelmingly composed from metallic materials. These implants show superior mechanical properties, but this can additionally result in stress shielding due to a modulus mismatch between the bone tissue and implanted device. Polymeric implants reduce this stress shielding effect but have much lower mechanical properties, limiting their use. Polylactic acid (PLA) is a widely used biodegradable thermoplastic polymer, however, its use has been limited by the polymer’s mechanical properties and rapid loss of strength during degradation in vivo. Polyether-ether-ketone (PEEK) is another common biocompatible polymer , with chemical and mechanical properties which make it a popular alternative …

Electrochemical Behaviour And Direct Cell Viability Analysis Of Hybrid Implants Made Of Ti-6al-4v Lattices Infiltrated With A Bioabsorbable Zn-Based Alloy, Noa Gabay Bass, Galit Katarivas Levy, Tomer Ron, Razi Vago, Jeremy Goldman, Amnon Shirizly, Eli Aghion

Michigan Tech Publications

Biodegradable metals are being developed for biomedical implants or components of implants. Biodegradable zinc-based materials, in particular, have been shown to promote bone regeneration in orthopaedic applications. Here, we investigated the potential of a hybrid Ti-Zn system, comprising a Ti-6Al-4V biostable lattice produced by additive manufacturing (AM) infiltrated by a bioabsorbable Zn-2%Fe alloy, to serve as an osseointegrated implant for dental and orthopaedic applications. The osseointegration of implants can be enhanced by a porous implant structure that facilitates bone ingrowth to achieve superior bonding between the bone tissue and the implant. The hybrid material was evaluated in terms of microstructure …

Additive Manufacturing Of Variable Contrast Computed Tomography Anatomical Phantoms Using A Single Feedstock In Fused Filament Fabrication, Cory J. Darling

University of New Orleans Theses and Dissertations

Anatomical phantoms used in biomedical education and training benefit greatly from Fused filament fabrication’s (FFF) ability to rapidly produce complex and unique models. Current materials and methods used in FFF have limited ability to accurately produce phantoms that can mimic the radiological properties of multiple biological tissues. This research demonstrates that the CT contrast of FFF produced models can be modified by varying the concentration of bismuth oxide in acrylonitrile butadiene styrene (ABS) filaments and a tunable CT contrast that mimics the CT contrast ranging from fatty tissue to cortical bone using a single composite filament without introducing artificial image …

Single Asperity Fretting Corrosion Of Traditional And Additively Manufactured Metallic Biomaterials: Quantitative Analysis From Acetabular Tapers To Micron And Nanometer Scale Tribocorrosion, Annsley Mace

All Dissertations

Mechanically assisted crevice corrosion (MACC) of metallic biomaterials continues to be a significant degradation mode. This is, in part, due to a lack of understanding of fundamental micron- and sub-micron scale mechanisms of metal degradation in biological environments. Metal-metal (or metal-hard) load bearing surfaces of hip arthroplasties are subjected to fretting crevice corrosion (FCC, one form of MACC). Current work in tribocorrosion involves large contact area tests with multiple asperities, with a distribution of load and wear that changes over time. A more systematic and controlled study of the FCC micro- and nanomechanics is needed.

Therefore, the goal of this …

Cost-Effective Non-Destructive Testing Of Biomedical Components Fabricated Using Additive Manufacturing, Santiago Fabian Cobos

Electronic Thesis and Dissertation Repository

Biocompatible titanium-alloys can be used to fabricate patient-specific medical components using additive manufacturing (AM). These novel components have the potential to improve clinical outcomes in various medical scenarios. However, AM introduces stability and repeatability concerns, which are potential roadblocks for its widespread use in the medical sector. Micro-CT imaging for non-destructive testing (NDT) is an effective solution for post-manufacturing quality control of these components. Unfortunately, current micro-CT NDT scanners require expensive infrastructure and hardware, which translates into prohibitively expensive routine NDT. Furthermore, the limited dynamic-range of these scanners can cause severe image artifacts that may compromise the diagnostic value of …

Formulation And Processing Of Dual Functional Adsorbent/Catalyst Structured Monoliths Using An Additively Manufactured Contactor For Direct Capture/Conversion Of Co2 With Cogeneration Of Ethylene, Shane Lawson, Khaled Baamran, Kyle Newport, Fateme Rezaei, Ali A. Rownaghi

Chemical and Biochemical Engineering Faculty Research & Creative Works

Utilizing CO₂ as a mild oxidant for oxidative dehydrogenation of ethane (ODHE) is an attractive way of recycling this greenhouse contaminant. Typically, CO₂ capture and conversion processes are performed in separate beds, however, combining these processes into one bed incurs advantages of lower thermal gradient and reduced energy costs. This study formulated the first generation of structured dual-functional materials (DFMs) by directly 3D printing metal-oxide-CaO/ZSM-5 inks into monolithic contactors. Specifically, we 3D-printed monoliths with V, Ga, Ni, or Ti dopants to perform metal screening and determine which metal generates the best structured DFM for combined CO₂ capture …

Assessing Leachable Cytotoxicity Of 3d-Printed Polymers And Facile Detoxification Methods, Venkatakrishnan Rengarajan, Angela Clyde, Jefferson Pontsler, Jonathan Valiente, Adreann Peel, Yu Huang

Biological Engineering Faculty Publications

Additive manufacturing of polymers is gaining momentum in health care industries by providing rapid 3D printing of customizable designs. Yet, little is explored about the cytotoxicity of leachable toxins that the 3D printing process introduced into the final product. We studied three printable materials, which have various mechanical properties and are widely used in stereolithography 3D printing. We evaluated the cytotoxicity of these materials through exposing two fibroblast cell lines (human and mouse derived) to the 3D-printed parts, using overlay indirect contact assays. All the 3D-printed parts were measured toxic to the cells in a leachable manner, with flexible materials …

A Highly Conductive, Flexible, And 3d-Printable Carbon Nanotube-Elastomer Ink For Additive Bio-Manufacturing, Andy Shar, Phillip Glass, Daeha Joung Ph.D.

Undergraduate Research Posters

The synthesis of a highly conductive, flexible, 3D-printable, and biocompatible ink has been of great interest in the field of bio-based additive manufacturing. Various applications include ultra-sensitive, microscale tactile sensors, patient-customizable scaffolds for cardiac and nerve tissue regeneration, and flexible electrocardiogram (ECG) electrodes. Here, a novel elastomeric carbon nanocomposite is presented consisting of amino-functionalized carbon nanotubes (CNT-NH₂) homogenously dispersed in a one-part room-temperature vulcanizing (RTV) silicone matrix. The use of acetone as a swelling solvent aids in electrical percolation through the elastomer matrix. CNT-NH₂ ratios can be tuned to fit various needs; higher tensile strength is favored …

Patient-Specific Cardiovascular Superelastic Niti Stents Produced By Laser Powder Bed Fusion, Valentina Finazzi, Francesca Berti, Roger J. Guillory Ii, Lorenza Petrini, Barbara Previtali, Ali Gökhan Demir

Michigan Tech Publications

To date, there is a general lack of customizability within the selection of endovascular devices for catheter-based vascular interventions. Laser powder bed fusion (LPBF) has been flexibly exploited to produce customized implants using conventional biomedical alloys for orthopedic and dental applications. Applying LPBF for cardiovascular applications, patient-specific stents can be produced with small struts (approximately 100-300 µm), variable geometries, and clinically used metals capable of superelastic behaviour at body temperature (eg. equiatomic nickel-titanium alloys, NiTi). Additionally, the growing availability and use of patient-specific 3D models provides a unique opportunity to outline the necessary manufacturing process that would be required for …