Three Dimensional Printing: Modern Medical Applications

3-D printing is an additive printing process based on inkjet printing principles. Using this technology, a variety of materials can be used to create a three-dimensional product. Currently this technology is expensive, however it is slowly becoming more affordable. 3-D printing has the potential to change the future of medical model production and prototyping, due to the beneficial products it can produce. The objective of this research study is to discover the technological advancements in 3-D printing that could greatly affect several aspects of the medical industry. The areas discussed include high-risk surgery, dentistry, and prosthetics. After conducting six interviews with medical professionals, it was discovered that 3-D printing is a viable technological source that all professionals are eager to use and implement into their medical line of work. 3-D printing is a revolutionary technology that has the possibility to positively affect the work of medical professionals, while enhancing the lives of others

Charge dynamics in the Mott insulating phase of the ionic Hubbard model

We extend to charge and bond operators the transformation that maps the ionic Hubbard model at half filling onto an effective spin Hamiltonian. Using these operators we calculate the amplitude of the charge density wave in different dimensions. In one dimension, the charge-charge correlations at large distance d decay as 1/(d^3 ln^{3/2}d), in spite of the presence of a charge gap, as a consequence of remaining charge-spin coupling. Bond-bond correlations decay as (-1)^d 1/(d ln^{3/2}d) as in the usual Hubbard model.Comment: 4 pages, no figures, submitted to Phys. Rev. B printing errors corrected and some clarifications adde

Open Source 3-D Printers: An Appropriate Technology for Developing Communities

International audienceThe recent introduction of RepRap (Self-Replicating Rapid Prototyper) 3-D printers and the resultant open source technological improvements have resulted in affordable 3-D printing, enabling low-cost distributed manufacturing for individuals. This development and others such as the rise of open source-appropriate technology (OSAT) and solar powered 3-D printing are moving 3-D printing from an industry specific technology to one that could be used in the developing world for sustainable development. In this paper, we explore some specific technological improvements and how distributed manufacturing with open-source 3-D printing can provide sustainable development by creating wealth for developing world communities through the ability to print less expensive and customized products. Conclusions on the technical viability of 3-D printing to assist in development and recommendations on how developing communities can fully exploit this technology have been outlined

3-D Printed microwave and tetrahertz passive components

This thesis presents the design of microwave and terahertz filters, fabricated using different types of 3-D printing technology. The work demonstrates the potential of using 3-D printing in the fabrication of microwave and terahertz passive components. The first project introduces a compact coaxial cavity resonator filter which was fabricated using stereolithography 3 D printing process. The size and volume of this filter reduced by almost half, by fitting one resonator inside another resonator. This filter is ideal for fabrication by 3 D printing, as such a complex structure cannot be made easily by other methods. This project demonstrates the advantage of using 3-D printing in fabrication of components with complex structures. The second project introduces three waveguide bandpass filters operating at centre frequency of 90 GHz, which were fabricated using the micro laser sintering process. The filters were the highest frequency metal 3-D printed filters reported at the time of publication. The third project introduces two waveguide filters operating at centre frequency of 180 GHz, which were also fabricated using the micro laser sintering process. These are the world highest frequency waveguide filters fabricated by a metal 3-D printing process. The capability of reproducibility of the micro laser sintering process is also discussed in this thesis. The fourth project introduces a hybrid coaxial bandpass filter with two symmetrical transmission zeros, which was fabricated using stereolithography 3-D printing process. In this project the main-line couplings and input/ output coupling were realized using PCB lines, the idea of using PCB lines instead of coupling irises or probes is to allow different topologies to be designed easily by altering the PCB layout. Finally, the fifth project introduces a terahertz waveguide bandpass filter with embedded H plane waveguide bends. This filter is being fabricated using 3-D screen printing

LOW-COST OPEN-SOURCE GMAW-BASED METAL 3-D PRINTING: MONITORING, SLICER, OPTIMIZATION, AND APPLICATIONS

Low-cost and open-source gas metal arc welding (GMAW)-based 3-D printing has been demonstrated yet the electrical design and software was not developed enough to enable wide-spread adoption. This thesis provides three novel technical improvements based on the application of mechatronic and software theory that when combined demonstrate the ability for distributed digital manufacturing at the small and medium enterprise scale of steel and aluminum parts. First, low cost metal inert gas welders contain no power monitoring needed to tune GMAW 3-D printers. To obtain this data about power and energy usage during the printing, an integrated monitoring system was developed to measure current (I) and voltage (V) in real-time. The new design of this monitoring system integrates an open source microcontroller and free and open source software on the open-source metal 3-D printer to record the data. Second, the primary obstacle to the diffusion of this technology was that existing slicing software, which determines the toolpath of the printhead was optimized for polymer 3-D printing and inappropriate for printed parts made from metal due to their mechanical strength. Previous prints were accomplished by manually designing the toolpath, which was not practical for real use by an extended userbase. To overcome the problem, the free and open-source slicing software, CuraEngine, was forked to MOSTMetalCura, which supports the needs of GMAW-based metal 3-D printing. The optimized setting for wire feed rate is calculated by the new slicer based on printing speed, bead width, layer height, and material diameter. Previous studies have shown that GMAW-based metal 3-D printing is capable of fabricating parts with good layer adhesion and porosity. However, this preliminary work lacked demonstrations of real-world applications. Finally, in this work, the practical applications of open-source GMAW-based metal 3-D printing are well demonstrated for both developing world and developed world applications including: 1) fixing an existing part by adding on a 3-D metal feature, 2) creating a product using the substrate as part of the component, 3) 3-D printing useful objects in high resolution, 4) near net shape objects and 5) making an integrated product using a combination of steel and polymer 3-D printing. The results prove that low-cost and open-source GMAW-based metal 3-D printing is ready for distributed manufacturing by SMEs and adequate for a wide range of applications

Producing Children\u27s Toys through 3-D Printing: A Multidisciplinary Approach

One of the things that first attracted me to VCU was the opportunity for interdisciplinary discussions and interactions. I saw HSURP as a way to push my boundaries and interact with peers from different disciplines. When I saw the Social Design and 3-D Printing project, it just clicked. I saw the opportunity for engineering, for arts, for research, for graphic design. All of the things I was interested in learning about all came together

3D printers in medicine, it present and future

This article is devoted to modern technologies in medicine and exactly to the technologies of 3D printing. The creation of 3-D printing back in 1984 brought the promise of a new age in manufacturing. Although it has only begun its takeoff, there is already so much we are able to do with the technology. From building screwdrivers to chairs to cars, the possibilities are endless. More importantly, however, is the impact of 3-D printing in medicine. In the past few years, biomedical engineers and physicians alike have realized that 3-D printing can make surgery, bone replacement, organ transfers, and other procedures a whole lot easier and more effective

Direct Freeform Fabrication of Spatially Heterogeneous Living Cell-Impregnated Implants

The objectives of this work are the development of the processes, materials, and tooling to directly “3-D print” living, pre-seeded, patient-specific implants of spatially heterogeneous compositions. The research presented herein attempts to overcome some of the challenges to scaffolding, such as the difficulty of producing spatially heterogeneous implants that require varied seeding densities and/or cell-type distributions. In the proposed approach, living implants are fabricated by the layer-wise deposition of pre-cell-seeded alginate hydrogel. Although alginate hydrogels have been previously used to mold living implants, the properties of the alginate formulations used for molding were not suitable for 3-D printing. In addition to changing the formulation to make the alginate hydrogels “printable,” we developed a robotic hydrogel deposition system and supporting CAD software to deposit the gel in arbitrary geometries. We demonstrated this technology’s capabilities by printing alginate gel implants of multiple materials with various spatial heterogeneities, including, implants with completely embedded material clusters. The process was determined to be both viable (94±5% n=15) and sterile (less than one bacterium per 0.9 µL after 8 days of incubation). Additionally, we demonstrated the printing of a meniscus cartilage-shaped gel generated directly from a CT Scan. The proposed approach may hold advantages over other tissue printing efforts [5,9]. This technology has the potential to overcome challenges to scaffolding and could enable the efficient fabrication of spatially heterogeneous, patient-specific, living implants.Mechanical Engineerin

3-D Printing, Copyright, and Fair Use: What Should We Know?

If the library is more than its collection, then use of 3-D printing to create knowledge is a good fit—but 3-D printing in library makerspaces can also provide greater access to collections by transforming 2-D images into 3-D tactile informational objects for use by blind or visually impaired patrons. Will new negotiations between libraries and publishers of journals, images, maps, and other visual resources now include access to files for 3-D printing tactile objects for on-demand creation of 3-D prints for tactile use? Is a 3-D print of a 2-D photo or digital image a derivative work? Will the treaty recently passed by the World Intellectual Property Organization (WIPO) positively impact the making of tactile learning objects? What must faculty and students know about copyright and fair use before beginning to make things with 3-D printers? Will libraries be responsible for providing makerspaces and staffing to assist in the production of tactile informational objects? ADA expectations for compliance change with availability of new technologies such as 3-D printing, which has been shown recently to be capable of producing tactile learning objects so blind or visually impaired students can sense through touch and feel what sighted students can see with microscopes and telescopes (www.nextgenemedia.com/ELDpres/assets/fallback/index.html). Whose responsibility is it to be sure that visual information contained in digital or 2-D form is made accessible to the blind patron? Does copyright stand in the way of making 3-D printed informational objects for use by visually impaired patrons? The impact of making 3-D printed informational objects will be discussed, and 3-D prints of microscope and telescope informational objects will be available for a touch and feel experience by attendees. It is expected that attendees will become more knowledgeable about how 3-D printing and related copyright issues can impact future library services and staffing