Palliation therapy for dysphagia using esophageal stents is the current treatment of choice for those patients with inoperable esophageal malignancies. However, the stents currently used in the clinical setting, regardless of the type of metal mesh or plastic mesh stents (covered/uncovered), may cause complications, such as tumor ingrowth and stent migration into the stomach. Furthermore, metal mesh stents have limited capacities for loading anti-cancer drugs. To effectively reduce/overcome those complications and enhance the efficacy of drug release, we designed and 3D-printed a tubular, flexible polymer stent with spirals, and then load anti-cancer drug, paclitaxel, on the stent for drug release. Non- spiral 3D-printed tubular and mesh polymer stents served as controls. The self-expansion and anti migration properties, cytotoxicity, drug release profile, and cancer cell inhibition of the 3D-printed stent were fully characterized. Results showed the self-expansion force of the 3D-printed polymer stent with spirals was slightly higher than the stent without spirals. The anti-migration force of the 3D-printed stent with spirals was significantly higher than the anti-migration force of a non-spiral stent. Furthermore, the stent with spirals significantly decreased the migration distance compared to the migration distance of the non-spiral 3D-printed polymer stent. The in vitro cytotoxicity of the new stent was examined through the viability test of human esophagus epithelial cells, and results indicated that the polymer stent does not have any cytotoxicity. The results of in vitro cell viability of esophageal cancer cells further indicated that the paclitaxel in the spiral stent treated esophageal cancer cells much more efficiently than that in the mesh stent. Furthermore, the results of the in vitro drug release profile and drug permeation showed that the dense tubular drug-loaded stent could efficiently be delivered more paclitaxel through the esophageal mucosa/submucosa layers in a unidirectional way than mesh stent that delivered less paclitaxel to the esophageal mucosa/submucosa but more to the lumen. In summary, these results showed that the 3D-printed dense polymer stent with spirals has promising potential to treat esophageal malignancies. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2019. / FAU Electronic Theses and Dissertations Collection

The aim of this work was to assess the feasibility of 3-D inkjet printing of elastomers in latex form to create a novel material that would offer shielding against electromagnetic interference (EMI). To achieve this aim it was necessary to characterise and select suitable materials, carry out ink jetting trials, modify the materials accordingly to improve the printability and assess post jetting conditions including drying and curing behaviour. Particle size, surface tension, and viscosity measurements were made for a series of elastomer latex materials and carboxylated styrene butadiene rubber (XSBR) latex was identified as the most suitable. Latex ink optimisation included dilution with water and the addition of a humectant, triethylene glycol monomethyl ether (TGME), which delayed drying and reduced nozzle blocking. The surface energy was measured for arrange of potential substrates and PET was identified as the most suitable, due to its relatively high surface energy which allowed for an ideal level of wetting and spreading. Analysis of the cross-sectional profiles of the printed samples by white light interferometry showed that drying during printing was an important issue for the latex ink. Ink jetting of a composite material with control of filler distribution was shown to be feasible when ten layers of conductive carbon black ink were deposited alternately between ten layers of XSBR ink. Printing was successfully carried out with a latex combined with a resorcinol resin which was subsequently cured, indicating that it should be possible to 3D print a thermoset elastomer in this way. Conductive carbon black was printed in various patterns onto PET sheet and the dielectric properties measured. Results indicated that at very low carbon contents, the printed patterns could provide EMI shielding. The research has shown that it is feasible to create a cured 3D elastomeric object containing filler with a controlled distribution that is capable of providing EMI shielding.

Der Beitrag berichtet, wie im Rahmen eines Forschungsvorhabens, welches durch das BMWi über einen Zeitraum von zwei Jahren gefördert wurde, ist untersucht worden, inwieweit der nachwachsende Rohstoff Miscanthus zur Herstellung von Verpackungen genutzt werden kann. Hierbei wurden zwei Verfahren, das Fasergussverfahren und das additive Fertigungsverfahren 3D-Printing, betrachtet. Beteiligt waren drei KMU und zwei gemeinnützige Forschungseinrichtungen.

Der Beitrag berichtet, wie im Rahmen eines Forschungsvorhabens, welches durch das BMWi über einen Zeitraum von zwei Jahren gefördert wurde, ist untersucht worden, inwieweit der nachwachsende Rohstoff Miscanthus zur Herstellung von Verpackungen genutzt werden kann. Hierbei wurden zwei Verfahren, das Fasergussverfahren und das additive Fertigungsverfahren 3D-Printing, betrachtet. Beteiligt waren drei KMU und zwei gemeinnützige Forschungseinrichtungen.

Design and performance of fully-printed Ku-band aperture coupled patch antennas fabricated by a direct digital manufacturing (DDM) approach that integrates fused deposition modeling (FDM) of acrylonitrile butadiene styrene (ABS) thermoplastic with in-situ micro-dispensing of conductive silver paste (CB028) are reported. Microstrip line characterizations are performed and demonstrate that misalignment of ABS substrate deposition direction with microstrip line micro-dispensing direction can degrade the effective conductivity up to 60% within the Ku-band, and must be taken into consideration in antenna array feed network designs. Specically, over 125 µm thick ABS substrate, RF loss of 0.052 dB/mm is obtained at 18 GHz, demonstrating the feasibility of additively manufactured RF devices within the Ku-band. By varying ABS inll ratios and resorting to multi-layer printing with custom substrate thicknesses, single and stacked patch antennas are designed, fabricated, and characterized with bandwidth performances up to 35%, and radiation efficiencies up to 90%. This extensive utilization of the design flexibilities provided by the direct digital manufacturing (i.e. customized substrate thicknesses, multiple substrates with varying infill ratios, and in-situ micro-dispensing of conductors) distinguishes the present work from the recently reported 3-D printed antennas. Compared to the existing work in literature, the antennas presented within this thesis stand out as being fully printed structures, operating in higher frequency range (i.e. Ku-band), and exhibiting high radiation efficiencies with wide bandwidth performances.

Archaeological conservation is the process by which conservators prevent deterioration of archaeological remains and provide insight into the nature of recovered material. This thesis examines the effect of digital technology upon the ethics of the conservation profession and upon the attitude of the lay-public towards archaeology. The ethical issues raised by the use of digital technology are discussed, particularly the ways in which these issues differ from those raised by traditional conservation methods. Technological advancements, particularly those occurring in the 20th century, changed the way artifacts are conserved and studied. Conservation arose out of a craft-restoration tradition and evolved into a profession which, in addition to necessary artistic and aesthetic considerations, uses a demonstrable scientific method in order to preserve artifacts. The creation of guidelines for practice and various codes of ethics is the turning point in this evolution, marking the point after which conservation became a scientific profession. Advances in computer technology have permitted the widespread use of devices such as 3-D scanners, digital CT scanners, and digital cameras in the conservation of archaeological artifacts. All of these pieces of equipment produced digital files which must be stored. Currently, the pace of technological change renders most data inaccessible within ten years, and data conservation problems such as storage, access, and file format have not been adequately addressed by the professional conservation community. There is a distinct lack of formal ethical guidelines concerning these issues; this thesis concludes that there is an extreme need for measured consideration before digital methods are used in archaeological conservation. The creation of high-fidelity replicas presents a problem for the museum audience. The public connects with artifacts on an emotional level which is altered when a replica is displayed instead of an original. Digital reconstructions abound in popular culture, heavily influencing public opinion, and often resulting in widespread misperception of the information which can be extracted from archaeological evidence. As a result, conservators of the future must be cautious when creating digital artifacts, and must be meticulously careful to make the nature of digital reconstruction clear to the audience, in order to avoid spreading misinformation.

Digital Craft is a project that explores the interface between three-dimensional (3-D) computer technology and costume technology. I combine seasoned millinery techniques with modern methods of object construction and design to diversify the costume artisan’s toolbox and encourage practical and useful ways of moving between the virtual and physical world. Through a series of theoretical projects the dichotomy of modern artistic process is explored. The task of this thesis project is to explore the impact of 3-D imaging software on design and construction methods by applying them to the sculptural process of hat making. I collaborate with designers and technicians to develop methods of hat making for performance culminating in an exhibition presented at the University Co-op Cohen New Works Festival, April 2011. This research is applied to cultivate new methods of hat making, by exploring new media and expanding creative possibilities. Craft objects are created directly through the hand of the maker; it is thorough technique that the hand informs the craft object (Risatti, 108). Furthermore, the traditional notion of tools and craft objects is that they are conditioned, controlled and limited by the hands. In order to update and improve methods of object construction, this project will expand the traditional concept of craft, combining hands-on methods with machining. I hope to improve efficiency and decrease the cost of realizing authentic and original hat designs by exploring alternative digital spaces that can be used to communicate, develop and actualize ideas. / text

Cellular materials, often called lattice materials, are increasingly receiving attention for their ultralight structures with high specific strength, excellent impact absorption, acoustic insulation, heat dissipation media and compact heat exchangers. In alignment with emerging additive manufacturing (AM) technology, realization of the structural applications of the lattice materials appears to be becoming faster. Considering the direction dependent material properties of the products with AM, by directionally dependent printing resolution, effective moduli of lattice structures appear to be directionally dependent. In this paper, a constitutive model of a lattice structure, which is an octet-truss with a base material having an orthotropic material property considering AM is developed. In a case study, polyjet based 3D printing material having an orthotropic property with a 9% difference in the principal direction provides difference in the axial and shear moduli in the octet-truss by 2.3 and 4.6%. Experimental validation for the effective properties of a 3D printed octet-truss is done for uniaxial tension and compression test. The theoretical value based on the micro-buckling of truss member are used to estimate the failure strength. Modulus value appears a little overestimate compared with the experiment. Finite element (FE) simulations for uniaxial compression and tension of octet-truss lattice materials are conducted. New effective properties for the octet-truss lattice structure are developed considering the observed behavior of the octet-truss structure under macroscopic compression and tension trough simulations.

Measurement of circulating protein biomarkers associated with disease can facilitate early detection, help guide treatment strategies and improve patient outcomes beyond current standards of care. The combination of inexpensive 3D-printed flow cells and electrochemical biosensors has recently emerged as a viable platform for low-cost, reliable biomarker measurements. Here, we report an electrochemical immunoassay system based on simple graphite electrode arrays, 3D-printed flow cells, and signal-generating magnetic bead bioconjugates for simultaneous detection of three biomarker proteins (cancer antigen 125 (CA-125), midkine (MK) and osteopontin (OPN)) associated with pediatric soft tissue sarcomas (PSTS). Magnetic bead bioconjugates are functionalized with large amounts of antibody and enzyme labels, electrode arrays are modified with gold nanoparticles and antibodies for specific capture of bioconjugate-labeled biomarkers, and 3D-printed flow cells facilitate their amperometric detection. Using this system, detection limits for CA-125, OPN and MK are 100 times lower than those obtained with commercial enzyme-linked immunosorbent assay (ELISA).

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