A review of additive manufacturing applications in ophthalmology

2021 ◽  
pp. 095441192110280
Author(s):  
Arivazhagan Pugalendhi ◽  
Rajesh Ranganathan
Keyword(s):  
Additive Manufacturing ◽  
Treatment Planning ◽  
Physical Object ◽  
Layer By Layer ◽  
Case Examples ◽  
Manufacturing Method ◽  
3D Cad ◽  
Stl File ◽  
Potential Applications ◽  
Manufacturing Applications

Additive Manufacturing (AM) capabilities in terms of product customization, manufacture of complex shape, minimal time, and low volume production those are very well suited for medical implants and biological models. AM technology permits the fabrication of physical object based on the 3D CAD model through layer by layer manufacturing method. AM use Magnetic Resonance Image (MRI), Computed Tomography (CT), and 3D scanning images and these data are converted into surface tessellation language (STL) file for fabrication. The applications of AM in ophthalmology includes diagnosis and treatment planning, customized prosthesis, implants, surgical practice/simulation, pre-operative surgical planning, fabrication of assistive tools, surgical tools, and instruments. In this article, development of AM technology in ophthalmology and its potential applications is reviewed. The aim of this study is nurturing an awareness of the engineers and ophthalmologists to enhance the ophthalmic devices and instruments. Here some of the 3D printed case examples of functional prototype and concept prototypes are carried out to understand the capabilities of this technology. This research paper explores the possibility of AM technology that can be successfully executed in the ophthalmology field for developing innovative products. This novel technique is used toward improving the quality of treatment and surgical skills by customization and pre-operative treatment planning which are more promising factors.

scholarly journals Mechanical characterization of additive manufacturing composite parts

Respuestas ◽  
2020 ◽  
Vol 25 (2) ◽  
Author(s):  
Juan Sebastian León-Becerra ◽  
Octavio A. González-Estrada ◽  
William Pinto-Hernández
Keyword(s):  
Additive Manufacturing ◽  
Mechanical Characterization ◽  
Solid Matrix ◽  
Elastic Model ◽  
Layer By Layer ◽  
Manufacturing Method ◽  
3D Cad ◽  
Linear Elastic ◽  
Stiffness Matrices

Additive Manufacturing is a novel manufacturing method in which the part is produced layer by layer from a 3D CAD model. In this work, we present the mechanical characterization of Fusion Deposition Modeling (FDM). Composite parts made by a nylon matrix with two kinds of fiber reinforcements: carbon fiber or fiberglass. From the obtained microstructure, we perform a division of the composite part in regions, and individual stiffness matrices are encountered by either using a linear elastic isotropic model, for the case of solid matrix filling, or an orthotropic linear elastic model based on micromechanical results. Then, a volume average stiffness method is employed to perform the characterization of the whole part. The theoretical results are compared with the experimental data, showing good agreement for both cases. This research allows the prediction of the structural behavior of additive manufacturing 2composite parts.

Increasing Part Accuracy in Additive Manufacturing Processes Using a k-d Tree Based Clustered Adaptive Layering

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Neeraj Panhalkar ◽  
Ratnadeep Paul ◽  
Sam Anand
Keyword(s):  
Additive Manufacturing ◽  
Computer Aided Design ◽  
Three Dimensional ◽  
Layer By Layer ◽  
Adaptive Slicing ◽  
Stl File ◽  
Build Time ◽  
Standard File Format ◽  
Aided Design ◽  
Profile Errors

Additive manufacturing (AM) is widely used in aerospace, automobile, and medical industries for building highly accurate parts using a layer by layer approach. The stereolithography (STL) file is the standard file format used in AM machines and approximates the three-dimensional (3D) model of parts using planar triangles. However, as the STL file is an approximation of the actual computer aided design (CAD) surface, the geometric errors in the final manufactured parts are pronounced, particularly in those parts with highly curved surfaces. If the part is built with the minimum uniform layer thickness allowed by the AM machine, the manufactured part will typically have the best quality, but this will also result in a considerable increase in build time. Therefore, as a compromise, the part can be built with variable layer thicknesses, i.e., using an adaptive layering technique, which will reduce the part build time while still reducing the part errors and satisfying the geometric tolerance callouts on the part. This paper describes a new approach of determining the variable slices using a 3D k-d tree method. The paper validates the proposed k-d tree based adaptive layering approach for three test parts and documents the results by comparing the volumetric, cylindricity, sphericity, and profile errors obtained from this approach with those obtained using a uniform slicing method. Since current AM machines are incapable of handling adaptive slicing approach directly, a “pseudo” grouped adaptive layering approach is also proposed here. This “clustered slicing” technique will enable the fabrication of a part in bands of varying slice thicknesses with each band having clusters of uniform slice thicknesses. The proposed k-d tree based adaptive slicing approach along with clustered slicing has been validated with simulations of the test parts of different shapes.

scholarly journals Fabrication of Demineralized Bone Matrix/Polycaprolactone Composites Using Large Area Projection Sintering (LAPS)

2019 ◽  
Vol 3 (2) ◽  
pp. 30 ◽  
Author(s):  
Mohsen Ziaee ◽  
Rebecca Hershman ◽  
Ayesha Mahmood ◽  
Nathan B. Crane
Keyword(s):  
Additive Manufacturing ◽  
Cancellous Bone ◽  
Demineralized Bone Matrix ◽  
Bone Matrix ◽  
Bone Allograft ◽  
Layer By Layer ◽  
Large Area ◽  
Manufacturing Method ◽  
Synthetic Scaffolds ◽  
Demineralized Bone

Cadaveric decellularized bone tissue is utilized as an allograft in many musculoskeletal surgical procedures. Typically, the allograft acts as a scaffold to guide tissue regeneration with superior biocompatibility relative to synthetic scaffolds. Traditionally these scaffolds are machined into the required dimensions and shapes. However, the geometrical simplicity and, in some cases, limited dimensions of the donated tissue restrict the use of allograft scaffolds. This could be overcome by additive manufacturing using granulated bone that is both decellularized and demineralized. In this study, the large area projection sintering (LAPS) method is evaluated as a fabrication method to build porous structures composed of granulated cortical bone bound by polycaprolactone (PCL). This additive manufacturing method utilizes visible light to selectively cure the deposited material layer-by-layer to create 3D geometry. First, the spreading behavior of the composite mixtures is evaluated and the conditions to attain improved powder bed density to fabricate the test specimens are determined. The tensile strength of the LAPS fabricated samples in both dry and hydrated states are determined and compared to the demineralized cancellous bone allograft and the heat treated demineralized-bone/PCL mixture in mold. The results indicated that the projection sintered composites of 45–55 wt %. Demineralized bone matrix (DBM) particulates produced strength comparable to processed and demineralized cancellous bone.

scholarly journals Additive Manufacturing of H11 with Wire-Based Laser Metal Deposition

2017 ◽  
Vol 22 (4) ◽  
pp. 466-479 ◽  
Author(s):  
Stella Holzbach Oliari ◽  
Ana Sofia Clímaco Monteiro D’Oliveira ◽  
Martin Schulz
Keyword(s):  
Additive Manufacturing ◽  
Travel Speed ◽  
Metal Deposition ◽  
Parameters Optimization ◽  
Layer By Layer ◽  
Laser Metal Deposition ◽  
3D Cad ◽  
Deposition Parameters ◽  
Commercial Applications ◽  
Functional Components

Abstract Laser additive manufacturing (LAM) is a near-net-shape production technique by which a part can be built up from 3D CAD model data, without material removal. Recently, these production processes gained attention due to the spreading of polymer-based processes in private and commercial applications. However, due to the insufficient development of metal producing processes regarding design, process information and qualification, resistance on producing functional components with this technology is still present. To overcome this restriction further studies have to be undertaken. The present research proposes a parametric study of additive manufacturing of hot work tool steel, H11. The selected LAM process is wire-based laser metal deposition (LMD-W). The study consists of parameters optimization for single beads (laser power, travel speed and wire feed rate) as well as lateral and vertical overlap for layer-by-layer technique involved in LMD process. Results show that selection of an ideal set of parameters affects substantially the surface quality, bead uniformity and bond between substrate and clad. Discussion includes the role of overlapping on the soundness of parts based on the height homogeneity of each layer, porosity and the presence of gaps. For the conditions tested it was shown that once the deposition parameters are selected, lateral and vertical overlapping determines the integrity and quality of parts processed by LAM.

On the Capabilities of a Multi-Modality 3D Bioprinter for Customized Biomedical Devices

2015 ◽  
Author(s):  
Prashanth Ravi ◽  
Panos S. Shiakolas ◽  
Tre Welch ◽  
Tushar Saini ◽  
Kristine Guleserian ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Device Fabrication ◽  
Layer By Layer ◽  
Fused Filament Fabrication ◽  
Stl File ◽  
Diverse Application ◽  
Multiple Materials ◽  
Manufacturing Platform ◽  
Single Construct ◽  
Manufacturing Technologies

Currently, there is a major shift in medical device fabrication research towards layer-by-layer additive manufacturing technologies; mainly owing to the relatively quick transition from a solid model (.STL file) to an actual prototype. The current manuscript introduces a Custom Multi-Modality 3D Bioprinter (CMMB) developed in-house, combining the Fused Filament Fabrication (FFF), Photo Polymerization (PP), Viscous Extrusion (VE), and Inkjet (IJ) printing technologies onto a single additive manufacturing platform. Methodologies to address limitation in the ability to customize construct properties layer-by-layer and to incorporate multiple materials in a single construct have been evaluated using open source 3D printing softwares Slic3r and Repetier-Host. Such customization empowers the user to fabricate constructs with tailorable anisotropic properties by combining different print technologies and materials. To this end, procedures which allow the integration of more than one distinct modality of the CMMB during a single print session were developed and evaluated, and are discussed. The current setup of the CMMB provides the capability to fabricate personalized medical devices using patient data from an MRI or a CT scan. Initial experiments and fabricated constructs demonstrate the potential of the CMMB for research in diverse application areas within biomedical engineering.

scholarly journals STUDIES ON MASK-LESS ELECTROCHEMICAL ADDITIVE MANUFACTURING

2021 ◽  
Author(s):  
Abhishek Bhardwaj
Keyword(s):  
Additive Manufacturing ◽  
High Power ◽  
Room Temperature ◽  
Three Dimensional ◽  
High Impact ◽  
Layer By Layer ◽  
Metal Parts ◽  
3D Cad ◽  
Cad Models

<div>Added substance Manufacturing (AM) of metallic designs is a warm cycle of layer by layer metal added substance fabricating measure produces parts straightforwardly from 3D CAD models. In this assembling interaction confined electrochemical affidavit joins with the added substance producing technique to make metal parts at room temperature. In this paper, the attainability of Mask-less Electrochemical Additive Manufacturing (ECAM), as a non-warm interaction is considered. Layer by layer testimony has been finished utilizing the electrochemical tips to make nickel microstructures. All the while beat wave qualities and their impacts on affidavit have been considered. </div><div>Confined electrodeposition (LED) was investigated as an AM the interaction with high power over measure boundaries and yield boundaries. The confinement of electrodeposition is completed by utilizing Ultra microelectrodes (UME) and low tossing power electrolytes. Variety in some cycle boundaries, for example, voltage and terminal hole are found to have a high impact on yield boundaries like thickness. The reproductions can anticipate the yield width of affidavit of analyses with a blunder of 8- 30%, so it can possibly apply as an added substance-producing strategy of complex three-dimensional (3D) parts on the microscale.</div>

Evaluation of Environmental Sustainability for Additive Manufacturing Batch Production

2017 ◽  
Author(s):  
Yiran Yang ◽  
Lin Li
Keyword(s):  
Additive Manufacturing ◽  
Environmental Sustainability ◽  
Production Method ◽  
Manufacturing Cost ◽  
Layer By Layer ◽  
Batch Production ◽  
Manufacturing Method ◽  
Current State ◽  
Layer Manufacturing ◽  
Batch Sizes

Additive manufacturing (AM), owning to the unique layer-by-layer manufacturing method and its associated advantages, has been implemented in a great number of industries. To further expand the AM applications, the current low throughput of AM system needs to be improved. Consequently, the batch production method, where multiple parts are fabricated in one batch, has gained increasing research interest. In the current state of literature, most research efforts assess the batch production approach based on its manufacturing cost saving potential. Nevertheless, environmental sustainability, serving as a critical part in AM development, is less explored. Environmental sustainability of AM batch production needs to be thoroughly investigated and assessed, due to the potential environmental impacts and human health risks that AM batch production activities might cause. This research aims to advance the state-of-the-art on environmental sustainability evaluation for AM batch production, by experimentally comparing three main environmental sustainability aspects (i.e., energy consumption, emission, and material waste) for batch production processes with different batch sizes. Based on the experimental results, the feasibility of batch production method for AM is discussed. The outcomes of this research will help evaluate the AM batch production method from an environmental sustainability standpoint, and facilitate the development of AM batch production.

scholarly journals A Layer-Arranged Meshless Method for the Simulation of Additive Manufacturing with Irregular Shapes

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 674
Author(s):  
Ming-Hsiao Lee ◽  
Wen-Hwa Chen ◽  
Ying Mao
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Meshless Method ◽  
Element Distribution ◽  
Layer By Layer ◽  
Analysis Model ◽  
Printing Process ◽  
Manufacturing Method ◽  
Geometry Model ◽  
Analysis Scheme

Additive manufacturing (3D Printing) has become a promising manufacturing method as it can produce parts in a flexible and efficient way, especially for very irregular parts. However, during the printing process, the material experiences a great temperature change from the melting temperature to room temperature; this causes high thermal strains and induces distinct deformations which degrade the quality of the printed parts, especially in metal 3D printing. In order to reduce possible problems and find possible solutions, a prior evaluation by simulation is often adopted. Nevertheless, since the 3D printing process generates parts in a layer-by-layer way, the analysis model should also be layer-by-layer arranged and used with a layer-by-layer based analysis process to simulate the layer-by-layer additive printing; otherwise, the simulation may not match the real behavior. In order to meet these requirements, a new meshless method is proposed to match the situations and handle these problems. As a meshless method, the modeling is not constrained by the element distribution. In addition, the analysis model generated with the proposed method can be arranged in a layer-by-layer way and combined with the proposed layer-by-layer analysis scheme, so it can then match and simulate the printing processes. Furthermore, the layer-by-layer arranged models can be automatically created, directly based on the STL (STereo-Lithography) geometry model, which is a de facto standard in the 3D printing industry. This makes the proposed approach more straightforward and efficient. To validate the proposed method, two parts with holes inside have been printed and simulated for comparison. The results show a good agreement. In addition, a highly irregular part has also been simulated to demonstrate the effectiveness and efficiency of this proposed method.

scholarly journals STUDIES ON MASK-LESS ELECTROCHEMICAL ADDITIVE MANUFACTURING

2021 ◽  
Author(s):  
Abhishek Bhardwaj
Keyword(s):  
Additive Manufacturing ◽  
High Power ◽  
Room Temperature ◽  
Three Dimensional ◽  
High Impact ◽  
Layer By Layer ◽  
Metal Parts ◽  
3D Cad ◽  
Cad Models

<div>Added substance Manufacturing (AM) of metallic designs is a warm cycle of layer by layer metal added substance fabricating measure produces parts straightforwardly from 3D CAD models. In this assembling interaction confined electrochemical affidavit joins with the added substance producing technique to make metal parts at room temperature. In this paper, the attainability of Mask-less Electrochemical Additive Manufacturing (ECAM), as a non-warm interaction is considered. Layer by layer testimony has been finished utilizing the electrochemical tips to make nickel microstructures. All the while beat wave qualities and their impacts on affidavit have been considered. </div><div>Confined electrodeposition (LED) was investigated as an AM the interaction with high power over measure boundaries and yield boundaries. The confinement of electrodeposition is completed by utilizing Ultra microelectrodes (UME) and low tossing power electrolytes. Variety in some cycle boundaries, for example, voltage and terminal hole are found to have a high impact on yield boundaries like thickness. The reproductions can anticipate the yield width of affidavit of analyses with a blunder of 8- 30%, so it can possibly apply as an added substance-producing strategy of complex three-dimensional (3D) parts on the microscale.</div>

scholarly journals EVALUATION OF OVERHANG ANGLE IN TIG WELDING-BASED WIRE ARC ADDITIVE MANUFACTURING PROCESS

2020 ◽  
Vol 7 (10) ◽  
pp. 247-254
Author(s):  
Omer Eyercioglu ◽  
Yusuf Atalay ◽  
Mehmet Aladag
Keyword(s):  
Additive Manufacturing ◽  
Manufacturing Process ◽  
Large Scale ◽  
Tig Welding ◽  
Layer By Layer ◽  
Manufacturing Method ◽  
Environment Temperature ◽  
Bead Height ◽  
Overhang Angle ◽  
Wire Arc Additive Manufacturing

Wire Arc Additive Manufacturing (WAAM) is a relatively new manufacturing method. It is a novel technique to build net-shaped or near-net-shaped metal components in a layer-by-layer manner via applying metal wire and selection of a heat source such as laser beam, electron beam, or electric arc. WAAM process is preferable as an alternative to traditional manufacturing methods especially for complex featured and large scale solid parts manufacturing and it is particularly used for aerospace structural components, manufacturing and repairing of dies/molds. TIG welding-based WAAM method is implemented by depositing continuous wire melted via heat. In this study, the overhang (self-supporting) angle in TIG welding-based wire arc additive manufacturing process is investigated. The overhang angles are the angles at which a 3D printer can build tapered (overhang) surfaces without the need to supporting material below the printing layer. The material, bead height, TIG weld parameters and the environment temperature (cooling rate of printed layer) are the parameters which affect the overhang angle. The results show that the maximum overhang angle is also dependent on the temperature of the previous layer. For the selected set of process parameters, the maximum overhang angle is found as 28o, if the temperature of the previous layer is cooled to 150oC before the subsequent layer is deposited.

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