scholarly journals Progress of 3D Bioprinting in Organ Manufacturing

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3178
Author(s):  
Dabin Song ◽  
Yukun Xu ◽  
Siyu Liu ◽  
Liang Wen ◽  
Xiaohong Wang
Keyword(s):  
Computer Aided Design ◽  
Three Dimensional ◽  
Research Progress ◽  
Layer By Layer ◽  
3D Bioprinting ◽  
Bioartificial Organs ◽  
Computer Aided ◽  
Bioactive Agents ◽  
Living Tissues ◽  
Aided Design

Three-dimensional (3D) bioprinting is a family of rapid prototyping technologies, which assemble biomaterials, including cells and bioactive agents, under the control of a computer-aided design model in a layer-by-layer fashion. It has great potential in organ manufacturing areas with the combination of biology, polymers, chemistry, engineering, medicine, and mechanics. At present, 3D bioprinting technologies can be used to successfully print living tissues and organs, including blood vessels, skin, bones, cartilage, kidney, heart, and liver. The unique advantages of 3D bioprinting technologies for organ manufacturing have improved the traditional medical level significantly. In this article, we summarize the latest research progress of polymers in bioartificial organ 3D printing areas. The important characteristics of the printable polymers and the typical 3D bioprinting technologies for several complex bioartificial organs, such as the heart, liver, nerve, and skin, are introduced.

scholarly journals Automatized Evaluation of Students’ CAD Models

2021 ◽  
Vol 11 (4) ◽  
pp. 145
Author(s):  
Nenad Bojcetic ◽  
Filip Valjak ◽  
Dragan Zezelj ◽  
Tomislav Martinec
Keyword(s):  
Computer Aided Design ◽  
Three Dimensional ◽  
Computer Application ◽  
Test Cases ◽  
Cad Model ◽  
Computer Solution ◽  
3D Cad ◽  
Computer Aided ◽  
Cad Models ◽  
Aided Design

The article describes an attempt to address the automatized evaluation of student three-dimensional (3D) computer-aided design (CAD) models. The driving idea was conceptualized under the restraints of the COVID pandemic, driven by the problem of evaluating a large number of student 3D CAD models. The described computer solution can be implemented using any CAD computer application that supports customization. Test cases showed that the proposed solution was valid and could be used to evaluate many students’ 3D CAD models. The computer solution can also be used to help students to better understand how to create a 3D CAD model, thereby complying with the requirements of particular teachers.

Determination of the Workspace of a Three-Degrees-of-Freedom Parallel Manipulator Using a Three-Dimensional Computer-Aided-Design Software Package and the Concept of Virtual Chains1

2015 ◽  
Vol 8 (2) ◽  
Author(s):  
Andrew Johnson ◽  
Xianwen Kong ◽  
James Ritchie
Keyword(s):  
Computer Aided Design ◽  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Graphical Representation ◽  
Three Dimensional ◽  
Parallel Manipulators ◽  
Workspace Analysis ◽  
Computer Aided ◽  
Aided Design

The determination of workspace is an essential step in the development of parallel manipulators. By extending the virtual-chain (VC) approach to the type synthesis of parallel manipulators, this technical brief proposes a VC approach to the workspace analysis of parallel manipulators. This method is first outlined before being illustrated by the production of a three-dimensional (3D) computer-aided-design (CAD) model of a 3-RPS parallel manipulator and evaluating it for the workspace of the manipulator. Here, R, P and S denote revolute, prismatic and spherical joints respectively. The VC represents the motion capability of moving platform of a manipulator and is shown to be very useful in the production of a graphical representation of the workspace. Using this approach, the link interferences and certain transmission indices can be easily taken into consideration in determining the workspace of a parallel manipulator.

An oriented feature extraction and recognition approach for concave-convex mixed interacting features in cast-then-machined parts

2018 ◽  
Vol 233 (4) ◽  
pp. 1269-1288 ◽  
Author(s):  
Haichao Wang ◽  
Jie Zhang ◽  
Xiaolong Zhang ◽  
Changwei Ren ◽  
Xiaoxi Wang ◽  
...  
Keyword(s):  
Feature Extraction ◽  
Computer Aided Design ◽  
Feature Recognition ◽  
Freeform Surface ◽  
Layer By Layer ◽  
Computer Aided Process Planning ◽  
Computer Aided ◽  
Machined Parts ◽  
Aided Design ◽  
Interacting Features

Feature recognition is an important technology of computer-aided design/computer-aided engineering/computer-aided process planning/computer-aided manufacturing integration in cast-then-machined part manufacturing. Graph-based approach is one of the most popular feature recognition methods; however, it cannot still solve concave-convex mixed interacting feature recognition problem, which is a common problem in feature recognition of cast-then-machined parts. In this study, an oriented feature extraction and recognition approach is proposed for concave-convex mixed interacting features. The method first extracts predefined features directionally according to the rules generated from attributed adjacency graphs–based feature library and peels off them from part model layer by layer. Sub-features in an interacting feature are associated via hints and organized as a feature tree. The time cost is reduced to less than [Formula: see text] by eliminating subgraph isomorphism and matching operations. Oriented feature extraction and recognition approach recognizes non-freeform-surface features directionally regardless of the part structure. Hence, its application scope can be extended to multiple kinds of non-freeform-surface parts by customizing. Based on our findings, implementations on prismatic, plate, fork, axlebox, linkage, and cast-then-machined parts prove that the proposed approach is applicable on non-freeform-surface parts and effectively recognize concave-convex mixed interacting feature in various mechanical parts.

scholarly journals The Influence of Exposure Energy Density on Porosity and Microhardness of the SLM Additive Manufactured Elements

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2304 ◽  
Author(s):  
Janusz Kluczyński ◽  
Lucjan Śnieżek ◽  
Krzysztof Grzelak ◽  
Janusz Mierzyński
Keyword(s):  
Computer Aided Design ◽  
Complex Geometry ◽  
Final Analysis ◽  
Machine Building ◽  
Layer By Layer ◽  
Laser Melting ◽  
Measurement Results ◽  
Computer Aided ◽  
Exposure Energy ◽  
Aided Design

Selective laser melting (SLM) is an additive manufacturing technique. It allows elements with very complex geometry to be produced using metallic powders. A geometry of manufacturing elements is based only on 3D computer-aided design (CAD) data. The metal powder is melted selectively layer by layer using an ytterbium laser. This paper contains the results of porosity and microhardness analysis made on specimens manufactured during a specially prepared process. Final analysis helped to discover connections between changing hatching distance, exposure speed and porosity. There were no significant differences in microhardness and porosity measurement results in the planes perpendicular and parallel to the machine building platform surface.

scholarly journals Development of integrated intelligent computer-aided design system for mechanical power-transmitting mechanism design

2017 ◽  
Vol 9 (7) ◽  
pp. 168781401771038 ◽  
Author(s):  
Isad Saric ◽  
Adil Muminovic ◽  
Mirsad Colic ◽  
Senad Rahimic
Keyword(s):  
Rapid Prototyping ◽  
Computer Aided Design ◽  
Three Dimensional ◽  
Computer Numerical Control ◽  
Numerical Control ◽  
Mechanical Power ◽  
Design System ◽  
Computer Aided ◽  
Aided Design ◽  
Intelligent Computer

This article presents architecture of integrated intelligent computer-aided design system for designing mechanical power-transmitting mechanisms (IICADkmps). The system has been developed in C# program environment with the aim of automatising the design process. This article presents a modern, automated approach to design. Developed kmps modules for calculation of geometrical and design characteristics of mechanical power-transmitting mechanisms are described. Three-dimensional geometrical parameter modelling of mechanical power-transmitting mechanisms was performed in the computer-aided design/computer-aided manufacturing/computer-aided engineering system CATIA V5. The connection between kmps calculation modules and CATIA V5 modelling system was established through initial three-dimensional models – templates. The outputs from the developed IICADkmps system generated final three-dimensional virtual models of mechanical power-transmitting mechanisms. Testing of the developed IICADkmps system was performed on friction, belt, cogged (spur and bevel gears) and chain transmitting mechanisms. Also, connection of the developed IICADkmps system with a device for rapid prototyping and computer numerical control machines was made for the purpose of additional testing and verification of practical use. Physical prototypes of designed characteristic elements of mechanical power-transmitting mechanisms were manufactured. The selected test three-dimensional virtual prototypes, obtained as an output from the developed IICADkmps system, were manufactured on the device for rapid prototyping (three-dimensional colour printer Spectrum Z510) and computer numerical control machines. Finally, at the end of the article, conclusions and suggested possible directions of further research, based on theoretical and practical research results, are presented.

Recognising Facial Surfaces

Perception ◽  
1991 ◽  
Vol 20 (6) ◽  
pp. 755-769 ◽  
Author(s):  
Vicki Bruce ◽  
Patrick Healey ◽  
Mike Burton ◽  
Tony Doyle ◽  
Anne Coombes ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Three Dimensional ◽  
Head Model ◽  
Matching Accuracy ◽  
The People ◽  
Computer Aided ◽  
Closed Head ◽  
The Face ◽  
Aided Design ◽  
Dimensional Surface

The extent to which faces depicted as surfaces devoid of pigmentation and with minimal texture cues (‘head models’) could be matched with photographs (when unfamiliar) and identified (when familiar) was examined in three experiments. The head models were obtained by scanning the three-dimensional surface of the face with a laser, and by displaying the surface measured in this way by using standard computer-aided design techniques. Performance in all tasks was above chance but far from ceiling. Experiment 1 showed that matching of unfamiliar head models with photographs was affected by the resolution with which the surface was displayed, suggesting that subjects based their decisions, at least in part, on three-dimensional surface structure. Matching accuracy was also affected by other factors to do with the viewpoints shown in the head models and test photographs, and the type of lighting used to portray the head model. In experiment 2 further evidence for the importance of the nature of the illumination used was obtained, and it was found that the addition of a hairstyle (not that of the target face) did not facilitate matching. In experiment 3 identification of the head models by colleagues of the people shown was compared with identification of photographs where the hair was concealed and eyes were closed. Head models were identified less well than these photographs, suggesting that the difficulties in their recognition are not solely due to the lack of hair. Women's heads were disproportionately difficult to recognise from the head models. The results are discussed in terms of their implications for the use of such three-dimensional head models in forensic and surgical applications.

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