Alumina-Doped Silica Gradient-Index (GRIN) Lenses by Slurry-Based Three-Dimensional Printing (S-3DP™)

2002 ◽  
Vol 758 ◽  
Author(s):  
Hong-Ren Wang ◽  
Michael J. Cima ◽  
Emanuel M. Sachs
Keyword(s):  
Complex Structure ◽  
Three Dimensional ◽  
Optical Quality ◽  
Vacuum Furnace ◽  
Gradient Index ◽  
Alumina Concentration ◽  
Graded Materials ◽  
Three Dimensional Printing ◽  
Dimensional Printing

ABSTRACTThe traditional Slurry-based Three-dimensional Printing (S-3DP™) process has been used to fabricate complex structure materials by printing organic binders in selected positions on each printing layer. This process is modified to fabricate functional graded materials, such as gradient index (GRIN) lenses, by depositing different concentrations of dopant at different positions. The modified S-3DP™ process offers advantages over conventional GRIN lens processes, including reduced processing time, improved compositional flexibility, and increased index profile dimensionality. Two different approximately parabolic dopant concentration profiles, which have maximum alumina concentrations of 1.63 mol% and 2.50 mol%, are printed into silica powder beds using S-3DP™. The samples with maximum alumina concentration of 1.63 mol% have been sintered into optical transparency at 1650 0C for 30 minutes in a vacuum furnace (5×10-6 torr) while an additional dehydration process before sintering was required for the samples with maximum alumina concentration of 2.50 mol%. The magnifying effects of GRIN lenses with profiles of 1.63 mol% and 2.50 mol% alumina were observed, yielding effective focal lengths of 10 cm and 6.1 cm, respectively. Light diffraction, which results from the locally inhomogeneous dopant distribution and reduces the optical quality of GRIN lenses, was also observed.

scholarly journals 3DP Technology for the Manufacture of Molds for Pressure Casting

2016 ◽  
Vol 16 (3) ◽  
pp. 99-102 ◽  
Author(s):  
G. Skorulski
Keyword(s):  
Calcium Sulfate ◽  
Copper Alloys ◽  
Three Dimensional ◽  
Pressure Casting ◽  
Gravity Casting ◽  
Three Dimensional Printing ◽  
Comparative Feature ◽  
Dimensional Printing ◽  
Calcium Sulfate Hemihydrate

Abstract The paper presents the use of rapid prototyping technology of three dimensional printing (3DP) to make a prototype shell casting mold. In the first step, for identification purposes, a mold was prepared to enable different alloys to be cast. All molds being cast were designed in a universal CAD environment and printed with the zp151 composite material (Calcium sulfate hemihydrate) with a zb63 binder (2-pyrrolidone). It is designated to be used to prepare colourful models presenting prototypes or casting models and molds. The usefulness of 3DP technology for use with copper alloys, aluminum and zinc was analyzed. The strength of the mold during casting was assumed as a characteristic comparative feature in the material resistance to high temperature, the quality of the resulting casting and its surface roughness. Casting tests were carried out in vacuum – pressure casting. The casting programs applied, significantly increased the quality of castings and enabled precise mold submergence. Significant improvement was noted in the quality compared to the same castings obtained by gravity casting.

scholarly journals Three-dimensional Printing in Spine Surgery: Protocol of a Systematic Review and Meta-analysis

2020 ◽  
Author(s):  
Guanli Xie ◽  
Tao Wang ◽  
Bo Jiang ◽  
Chunyan Yang ◽  
Deguang Li ◽  
...  
Keyword(s):  
3D Printing ◽  
Spinal Surgery ◽  
Three Dimensional ◽  
Clinical Heterogeneity ◽  
Three Dimensional Printing ◽  
3D Printing Technology ◽  
Randomized Controlled ◽  
Randomized Controlled Studies ◽  
Dimensional Printing

Abstract BackgroundThe complexity and diversity of spine pathology lead to the complexity and diversity of spinal surgery. The emergence and application of three-dimensional printing (3DP) technology has brought good news to surgeons and patients. However, the use of 3DP in spinal surgery remains controversial. Therefore, this study was designed to investigate whether 3D printing technology is beneficial for spinal surgery.MethodsThree English online databases including EMBASE (via embase.com), Medline (via PubMed), and Cochrane Central Register of Controlled Trials (CENTRAL) will be searched from inception until August 31, 2020. Document records retrieved according to the pre-defined search strategy will be managed by EndNote X7. The MINORST (methodological index for non-randomized studies) item recommended for non-randomized controlled interventional studies in surgery will be used to assess the quality of non-randomized controlled studies. The “Risk of bias” (ROB) table will be used to assess the quality of randomized controlled studies. The data extraction will be completed by two authors independently, one of whom extracts and the other checks. If there is any missing data, original author will be contacted to obtain the data required. Any inconsistencies were agreed upon by discussion with a third investigator. If the collected data can be synthesized, Review Manager (RevMan5.3) will be used to estimate the overall effect of 3DP for Spinal surgery. Otherwise, only the qualitative analysis will be carried out. According to the results of clinical heterogeneity test, random effects model or fixed effects model will be used for data synthesis. The sources of clinical heterogeneity will be explored by meta-regression and subgroup analysis. If more than 10 studies are included, funnel plots will be used to assess the publication bias. This review will be carried out in strict accordance with Cochrane Handbook for Systematic Reviews of Interventions.ConclusionThis study will can provide surgeons and patients with evidence-based evidence for the use of 3D printing technology in spinal surgery.Systematic review registrationPROSPERO/ID = CRD42020204053.

3D Reconstruction Role in Surgical Treatment of Sinonasal Tumours

2018 ◽  
Vol 69 (6) ◽  
pp. 1455-1457
Author(s):  
Dragos Octavian Palade ◽  
Bogdan Mihail Cobzeanu ◽  
Petronela Zaharia ◽  
Marius Dabija
Keyword(s):  
3D Printing ◽  
Three Dimensional ◽  
Patient Specific ◽  
Three Dimensional Printing ◽  
Great Progress ◽  
3D Printed ◽  
Medical Modeling ◽  
Dimensional Printing ◽  
Tissue Defects

Three-dimensional printing has numerous applications and has gained much interest in the medical world. The constantly improving quality of 3D-printing applications has contributed to their increased use on patients. Nowadays, 3D printing is very well integrated in the surgical practice and research. Also, the field of head and neck reconstructive surgery is constantly evolving because of the three-dimensional printing, a technology which can be widely used in a variety of situations such as reconstruction of tissue defects, surgical planning, medical modeling and prosthesis. By using 3D printing into tissue engineering and materials, it may be possible for otolaryngologists to implant 3D printed functional grafts into patients and will also provide a rapid production of personalized patient-specific devices. Advances in 3D printed implants and future tissue-engineered constructs will bring great progress to the field of otorhinolaryngology.

scholarly journals Bioartificial Organ Manufacturing Technologies

2018 ◽  
Vol 28 (1) ◽  
pp. 5-17 ◽  
Author(s):  
Xiaohong Wang
Keyword(s):  
Three Dimensional ◽  
Human Beings ◽  
Three Dimensional Printing ◽  
Advantages And Disadvantages ◽  
Human Organs ◽  
Manufacturing Technologies ◽  
Near Future ◽  
First Time ◽  
Dimensional Printing

Bioartificial organ manufacturing technologies are a series of enabling techniques that can be used to produce human organs based on bionic principles. During the last ten years, significant progress has been achieved in the development of various organ manufacturing technologies. According to the degree of automation, organ manufacturing technologies can be divided into three main groups: (1) fully automated; (2) semi-automated; (3) handworked (or handmade); each has the advantages and disadvantages for bioartificial organ manufacturing. One of the most promising bioartificial organ manufacturing technologies is to use combined multi-nozzle three-dimensional printing techniques to automatically assemble personal cells along with other biomaterials to build exclusive organ substitutes for defective/failed human organs. This is the first time that advanced bioartificial organ manufacturing technologies have been reviewed. These technologies hold the promise to greatly improve the quality of health and average lifespan of human beings in the near future.

scholarly journals Design of urban furniture to enhance the soundscape: A case study

2018 ◽  
Vol 25 (1) ◽  
pp. 61-75 ◽  
Author(s):  
Gioia Fusaro ◽  
Francesco D’Alessandro ◽  
Giorgio Baldinelli ◽  
Jian Kang
Keyword(s):  
Three Dimensional ◽  
Experimental Tests ◽  
Open Spaces ◽  
Three Dimensional Printing ◽  
Historical Heritage ◽  
Environmental Feasibility ◽  
The Relationship ◽  
Dimensional Printing

In modern urban scenarios, all the aspects of the historical heritage, including public open spaces and ancient buildings, have to meet the high increase of density of infrastructures and constructions, with the consequent change of visual and sound environments. This in turn affects people’s quality of life. Because of the growing interest on this problem, this study investigates the relationship between soundscape and design solutions for urban furniture, considering technical and environmental feasibility of the designing process, from the materials characteristics, to the acoustic and psychoacoustic impact of the tool on the user. The process includes the acoustic suitability of three-dimensional printing materials, the suitability of acoustic design using software simulation, the experimental assessment of the performance of the three-dimensional printed prototype and the statistical evaluation of the chosen studying parameters and conditions. This article describes all the stages of the designing process, with a focus on the study of shapes and volumes of the prototype and on its impact on the user’s perception. FEM simulations and experimental tests performed in a semi-anechoic chamber allowed to validate the design process. These analyses proved that the designed prototype of urban furniture can not only positively influence the physical environment but also the psychoacoustic perception of it.

Analysis of Extrusion Parameters for the Fused Deposition Modeling Process

2020 ◽  
Author(s):  
Wenqiang Yu ◽  
Zhengwei Nie ◽  
Yuyi Lin ◽  
Huakai Jiang
Keyword(s):  
Fused Deposition Modeling ◽  
Three Dimensional ◽  
Three Dimensional Printing ◽  
Technical Parameters ◽  
Fused Deposition ◽  
Modeling Process ◽  
Deposition Modeling ◽  
Dimensional Printing ◽  
Screw Pitch

Abstract Fused deposition modeling (FDM) is an additive manufacturing technology commonly used for three-dimensional printing. The screw rod is an important part of the extrusion nozzle in the FDM manufacturing. The technical parameters of the screw rod, such as the screw pitch, screw angle, groove width, and length-diameter ratio (or aspect ratio), etc., directly determine the speed of extrusion and the precision of modeling. To improve the printing speed and quality of FDM models, this work analyzed the influence of extrusion screw’s parameters on the extrusion flow rate and proposed the best parameters for the screw rod of the FDM process. The results of this work have a crucial significance on the modeling speed and accuracy of the FDM.

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