Developments in the Field of Rapid Prototype Production

2008 ◽  
Vol 589 ◽  
pp. 421-425 ◽  
Author(s):  
Norbert Krisztián Kovács ◽  
József Gábor Kovács

Characteristics of 3D printed specimens are porous structure and low mechanical strength. Due to porous structure post treatment is possible, and in most cases infiltration with an epoxy resin, wax or cyanoacrylate material takes place. As a result of post treatment, the mechanical strength can be increased by 100%, although this is strongly influenced by the infiltration depth that depends on the porous structure and the resin viscosity. In the framework of the common research of the Department of Polymer Engineering, BME and Varinex Zrt. the applicability of a 3D printer is examined in the field of direct tool making. As the first step, the resin uptake ability of specimens prepared with a Z810 3D printer is examined.

History of additive manufacturing started in the 1980s in Japan. Stereolithography was invented first in 1983. After that tens of other techniques were invented under the common name 3D printing. When stereolithography was invented rapid prototyping did not exists. Tree years later new technique was invented: selective laser sintering (SLS). First commercial SLS was in 1990. At the end of 20t century, first bio-printer was developed. Using bio materials, first kidney was 3D printed. Ten years later, first 3D Printer in the kit was launched to the market. Today we have large scale printers that printed large 3D objects such are cars. 3D printing will be used for printing everything everywhere. List of pros and cons questions rising every day.


2018 ◽  
Vol 223 ◽  
pp. 21-24 ◽  
Author(s):  
Hongxia Zhao ◽  
Lihua Li ◽  
Shan Ding ◽  
Chenxing Liu ◽  
Jiaoyan Ai

Author(s):  
R.L. Pinto ◽  
R.M. Woollacott

The basal body and its associated rootlet are the organelles responsible for anchoring the flagellum or cilium in the cytoplasm. Structurally, the common denominators of the basal apparatus are the basal body, a basal foot from which microtubules or microfilaments emanate, and a striated rootlet. A study of the basal apparatus from cells of the epidermis of a sponge larva was initiated to provide a comparison with similar data on adult sponges.Sexually mature colonies of Aplysillasp were collected from Keehi Lagoon Marina, Honolulu, Hawaii. Larvae were fixed in 2.5% glutaraldehyde and 0.14 M NaCl in 0.2 M Millonig’s phosphate buffer (pH 7.4). Specimens were postfixed in 1% OsO4 in 1.25% sodium bicarbonate (pH 7.2) and embedded in epoxy resin. The larva ofAplysilla sp was previously described (as Dendrilla cactus) based on live observations and SEM by Woollacott and Hadfield.


2021 ◽  
Vol 10 (8) ◽  
pp. 1740
Author(s):  
Marion Bareille ◽  
Michaël Hardy ◽  
Jonathan Douxfils ◽  
Stéphanie Roullet ◽  
Dominique Lasne ◽  
...  

Infection by SARS-CoV-2 is associated with a high risk of thrombosis. The laboratory documentation of hypercoagulability and impaired fibrinolysis remains a challenge. Our aim was to assess the potential usefulness of viscoelastometric testing (VET) to predict thrombotic events in COVID-19 patients according to the literature. We also (i) analyzed the impact of anticoagulation and the methods used to neutralize heparin, (ii) analyzed whether maximal clot mechanical strength brings more information than Clauss fibrinogen, and (iii) critically scrutinized the diagnosis of hypofibrinolysis. We performed a systematic search in PubMed and Scopus databases until December 31st, 2020. VET methods and parameters, and patients’ features and outcomes were extracted. VET was performed for 1063 patients (893 intensive care unit (ICU) and 170 non-ICU, 44 studies). There was extensive heterogeneity concerning study design, VET device used (ROTEM, TEG, Quantra and ClotPro) and reagents (with non-systematic use of heparin neutralization), timing of assay, and definition of hypercoagulable state. Notably, only 4 out of 25 studies using ROTEM reported data with heparinase (HEPTEM). The common findings were increased clot mechanical strength mainly due to excessive fibrinogen component and impaired to absent fibrinolysis, more conspicuous in the presence of an added plasminogen activator. Only 4 studies out of the 16 that addressed the point found an association of VETs with thrombotic events. So-called functional fibrinogen assessed by VETs showed a variable correlation with Clauss fibrinogen. Abnormal VET pattern, often evidenced despite standard prophylactic anticoagulation, tended to normalize after increased dosing. VET studies reported heterogeneity, and small sample sizes do not support an association between the poorly defined prothrombotic phenotype of COVID-19 and thrombotic events.


Author(s):  
Mahima Singh ◽  
Sriramakamal Jonnalagadda

AbstractThis study evaluates the suitability of 3D printed biodegradable mats to load and deliver the topical antibiotic, neomycin, for up to 3 weeks in vitro. A 3D printer equipped with a hot melt extruder was used to print bandage-like wound coverings with porous sizes appropriate for cellular attachment and viability. The semicrystalline polyester, poly-l-lactic acid (PLLA) was used as the base polymer, coated (post-printing) with polyethylene glycols (PEGs) of MWs 400 Da, 6 kDa, or 20 kDa to enable manipulation of physicochemical and biological properties to suit intended applications. The mats were further loaded with a topical antibiotic (neomycin sulfate), and cumulative drug-release monitored for 3 weeks in vitro. Microscopic imaging as well as Scanning Electron Microscopy (SEM) studies showed pore dimensions of 100 × 400 µm. These pore dimensions were achieved without compromising mechanical strength; because of the “tough” individual fibers constituting the mat (Young’s Moduli of 50 ± 20 MPa and Elastic Elongation of 10 ± 5%). The in vitro dissolution study showed first-order release kinetics for neomycin during the first 20 h, followed by diffusion-controlled (Fickian) release for the remaining duration of the study. The release of neomycin suggested that the ability to load neomycin on to PLLA mats increases threefold, as the MW of the applied PEG coating is lowered from 20 kDa to 400 Da. Overall, this study demonstrates a successful approach to using a 3D printer to prepare porous degradable mats for antibiotic delivery with potential applications to dermal regeneration and tissue engineering.


2020 ◽  
Vol 17 (03) ◽  
pp. 2050010
Author(s):  
Saeed Saeedvand ◽  
Hadi S. Aghdasi ◽  
Jacky Baltes

Although there are several popular and capable humanoid robot designs available in the kid-size range, they lack some important characteristics: affordability, being user-friendly, using a wide-angle camera, sufficient computational resources for advanced AI algorithms, and mechanical robustness and stability are the most important ones. Recent advances in 3D printer technology enables researchers to move from model to physical implementation relatively easy. Therefore, we introduce a novel fully 3D printed open platform humanoid robot design named ARC. In this paper, we discuss the mechanical structure and software architecture. We show the capabilities of the ARC design in a series of experimental evaluations.


2019 ◽  
Vol 964 ◽  
pp. 240-245 ◽  
Author(s):  
Amaliya Rasyida ◽  
Thalyta Rizkha Pradipta ◽  
Sigit Tri Wicaksono ◽  
Vania Mitha Pratiwi ◽  
Yeny Widya Rakhmawati

Utilization of brown algae especially in Madura, where it’s close to Surabaya, only limited for food. This become a reference for developing and increasing the potential of this algae by extracting one of the ingredients, namely alginate. This paper deals with the characterization of sodium alginate extracted from sargassum sp. using modified-purified calcium routes. The extracted sodium alginate will be further used as composite hydrogel materials and compared with commercial sodium alginate. Hereafter, the synthesized composite is expected to be bio-ink for 3d printer. Chemical composition analysis were analyzed using X-Ray Fluorosense (XRF) followed by Fourier-transform infrared spectroscopy (FTIR) analysis to identify the functional group of composite and X-Ray Diffraction (XRD). Furthermore, viscosity bath is performed to compare the viscosity of extracted and commercial one. The result shows that modified-purified calcium routes in the extraction process of sodium alginate is desirable for improving their properties. Interestingly enough, with the goal of using it as bio-ink in 3d printed fabrication, the synthesized composite shows viscosity, 300 cSt, which meets the criteria for bio-ink in 3d printer.


2021 ◽  
Vol 26 (1) ◽  
Author(s):  
Lukas Postl ◽  
Thomas Mücke ◽  
Stefan Hunger ◽  
Oliver Bissinger ◽  
Michael Malek ◽  
...  

Abstract Background The accuracy of computer-assisted biopsies at the lower jaw was compared to the accuracy of freehand biopsies. Methods Patients with a bony lesion of the lower jaw with an indication for biopsy were prospectively enrolled. Two customized bone models per patient were produced using a 3D printer. The models of the lower jaw were fitted into a phantom head model to simulate operation room conditions. Biopsies for the study group were taken by means of surgical guides and freehand biopsies were performed for the control group. Results The deviation of the biopsy axes from the planning was significantly less when using templates. It turned out to be 1.3 ± 0.6 mm for the biopsies with a surgical guide and 3.9 ± 1.1 mm for the freehand biopsies. Conclusions Surgical guides allow significantly higher accuracy of biopsies. The preliminary results are promising, but clinical evaluation is necessary.


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