Volumetric additive manufacturing via tomographic reconstruction

Science ◽  
2019 ◽  
Vol 363 (6431) ◽  
pp. 1075-1079 ◽  
Author(s):  
Brett E. Kelly ◽  
Indrasen Bhattacharya ◽  
Hossein Heidari ◽  
Maxim Shusteff ◽  
Christopher M. Spadaccini ◽  
...  

Additive manufacturing promises enormous geometrical freedom and the potential to combine materials for complex functions. The speed, geometry, and surface quality limitations of additive processes are linked to their reliance on material layering. We demonstrated concurrent printing of all points within a three-dimensional object by illuminating a rotating volume of photosensitive material with a dynamically evolving light pattern. We printed features as small as 0.3 millimeters in engineering acrylate polymers and printed soft structures with exceptionally smooth surfaces into a gelatin methacrylate hydrogel. Our process enables us to construct components that encase other preexisting solid objects, allowing for multimaterial fabrication. We developed models to describe speed and spatial resolution capabilities and demonstrated printing times of 30 to 120 seconds for diverse centimeter-scale objects.

Author(s):  
Andrew J. Birnbaum ◽  
Athanasios P. Iliopoulos ◽  
John C. Steuben ◽  
John G. Michopoulos

Despite increasing levels of acceptance, traditional additive manufacturing techniques continue to suffer from a number of fundamental drawbacks that act to limit broad adoption. These drawbacks include limits on processable materials, part properties/performance, geometric deviation and repeatability. The vast majority of existing processes also rely on a point-by-point approach to generate parts, resulting in exceedingly long build times and extremely poor scaling behavior. Furthermore, in general, current systems require significant levels of complexity for operation, resulting in the need for considerable upfront capital investment as well as continuing maintenance costs. A new manufacturing approach is presented here, based upon the generation of objects from the direct creation of constituent volumetric sub-regions. This process addresses many of the limitations described above, and has the potential to significantly alter the manner with which three-dimensional objects are realized.


2021 ◽  
Author(s):  
Yuan Yao ◽  
Cheng Ding ◽  
Mohamed Aburaia ◽  
Maximilian Lackner ◽  
Lanlan He

Abstract The Fused Filament Fabrication process is the most used additive manufacturing process due to its simplicity and low operating costs. In this process, a thermoplastic filament is led through an extruder, melted, and applied to a building platform by the axial movements of an automated Cartesian system in such a way that a three-dimensional object is created layer by layer. Compared to other additive manufacturing technologies, the components produced have mechanical limitations and are often not suitable for functional applications. To reduce the anisotropy of mechanical strength in fused filament fabrication (FFF), this paper proposes a 3D weaving deposit path planning method that utilizes a 5-layer repetitive structure to achieve interlocking and embedding between neighbor slicing planes to improve the mechanical linkage within the layers. The developed algorithm extends the weaving path as an infill pattern to fill different structures and makes this process feasible on a standard three-axis 3D printer. Compared with 3D weaving printed parts by layer-to-layer deposit, the anisotropy of mechanical properties inside layers is significantly reduced to 10.21% and 0.98%.


2018 ◽  
Vol 25 (6) ◽  
pp. 1819-1826 ◽  
Author(s):  
Haiyan Yu ◽  
Sihao Xia ◽  
Chenxi Wei ◽  
Yuwei Mao ◽  
Daniel Larsson ◽  
...  

Novel developments in X-ray sources, optics and detectors have significantly advanced the capability of X-ray microscopy at the nanoscale. Depending on the imaging modality and the photon energy, state-of-the-art X-ray microscopes are routinely operated at a spatial resolution of tens of nanometres for hard X-rays or ∼10 nm for soft X-rays. The improvement in spatial resolution, however, has led to challenges in the tomographic reconstruction due to the fact that the imperfections of the mechanical system become clearly detectable in the projection images. Without proper registration of the projection images, a severe point spread function will be introduced into the tomographic reconstructions, causing the reduction of the three-dimensional (3D) spatial resolution as well as the enhancement of image artifacts. Here the development of a method that iteratively performs registration of the experimentally measured projection images to those that are numerically calculated by reprojecting the 3D matrix in the corresponding viewing angles is shown. Multiple algorithms are implemented to conduct the registration, which corrects the translational and/or the rotational errors. A sequence that offers a superior performance is presented and discussed. Going beyond the visual assessment of the reconstruction results, the morphological quantification of a battery electrode particle that has gone through substantial cycling is investigated. The results show that the presented method has led to a better quality tomographic reconstruction, which, subsequently, promotes the fidelity in the quantification of the sample morphology.


2020 ◽  
Vol 21 (S6) ◽  
Author(s):  
Lun Li ◽  
Renmin Han ◽  
Zhaotian Zhang ◽  
Tiande Guo ◽  
Zhiyong Liu ◽  
...  

Abstract Background Electron tomography (ET) is an important technique for the study of complex biological structures and their functions. Electron tomography reconstructs the interior of a three-dimensional object from its projections at different orientations. However, due to the instrument limitation, the angular tilt range of the projections is limited within +70∘ to −70∘. The missing angle range is known as the missing wedge and will cause artifacts. Results In this paper, we proposed a novel algorithm, compressed sensing improved iterative reconstruction-reprojection (CSIIRR), which follows the schedule of improved iterative reconstruction-reprojection but further considers the sparsity of the biological ultra-structural content in specimen. The proposed algorithm keeps both the merits of the improved iterative reconstruction-reprojection (IIRR) and compressed sensing, resulting in an estimation of the electron tomography with faster execution speed and better reconstruction result. A comprehensive experiment has been carried out, in which CSIIRR was challenged on both simulated and real-world datasets as well as compared with a number of classical methods. The experimental results prove the effectiveness and efficiency of CSIIRR, and further show its advantages over the other methods. Conclusions The proposed algorithm has an obvious advance in the suppression of missing wedge effects and the restoration of missing information, which provides an option to the structural biologist for clear and accurate tomographic reconstruction.


2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Xiaojun Jia ◽  
Zihao Liu

Pattern encoding and decoding are two challenging problems in a three-dimensional (3D) reconstruction system using coded structured light (CSL). In this paper, a one-shot pattern is designed as an M-array with eight embedded geometric shapes, in which each 2 × 2 subwindow appears only once. A robust pattern decoding method for reconstructing objects from a one-shot pattern is then proposed. The decoding approach relies on the robust pattern element tracking algorithm (PETA) and generic features of pattern elements to segment and cluster the projected structured light pattern from a single captured image. A deep convolution neural network (DCNN) and chain sequence features are used to accurately classify pattern elements and key points (KPs), respectively. Meanwhile, a training dataset is established, which contains many pattern elements with various blur levels and distortions. Experimental results show that the proposed approach can be used to reconstruct 3D objects.


Author(s):  
Mamta H. Wankhade ◽  
Satish G. Bahaley

<p>3D printing is a form of additive manufacturing technology where a three dimensional object is created by laying down successive layers of material. It is mechanized method whereby 3D objects are quickly made on a reasonably sized machine connected to a computer containing blueprints for the object. As 3D printing is growing fast and giving a boost to product development, the factories doing 3D printing need to continuously meet the printing requirements and maintain an adequate amount of inventory of the filament. As the manufactures have to buy these filaments from various vendors, the cost of 3D printing increases. To overcome the problem faced by the manufacturers, small workshop owners, the need of 3D filament making machine arises. This project focuses on designing and fabricating a portable fused deposition 3D printer filament making machine with cheap and easily available components to draw 1.75 mm diameter ABS filament.</p>


Author(s):  
V. Kovan ◽  
G. Altan ◽  
E.S. Topal ◽  
H.E. Camurlu

Three-dimensional printing or 3D printing (also called additive manufacturing) is any of various processes used to make a three-dimensional object. Fused deposition modelling (FDM) is an additive manufacturing technology commonly used for modelling, prototyping, and production applications. It is one of the techniques used for 3D printing. FDM is somewhat restricted in the size and the variation of shapes that may be fabricated. For parts too large to fit on a single build, for faster job builds with less support material, or for parts with finer features, sectioning and bonding FDM parts is a great solution. The strength of adhesive bonded FDM parts is affected by the surface roughness. In this study, the layer thickness effect on bonding strength is experimentally studied and the results are discussed.


3D Printing ◽  
2017 ◽  
pp. 145-152
Author(s):  
Tihomir Mitev

The additive manufacturing (or the popular 3D printing) is relatively new technology which opens new spaces for entrepreneurial imagination and promises next stage of the industrial revolution. It is creating three dimensional solid objects from a digital file. The printer transforms the file into a material object layer by layer, using different raw materials. Today, the additive manufacturing is successfully used in architecture, medicine and healthcare, light and heavy industries, education, etc. The paper analyses the roles of actors in manufacturing the objects. It starts with the Heideggerian questioning of technology (), searching for the causes of bringing into appearance of the 3D model. According to Heideggerian analysis the technology is represented as an ‘unveiling of the truth'. The paper suggests that the old understanding of matter as a thing-in-itself should be replaced by a new, flexible, fluid, concept of matter, which is more or less manipulable. The matter is no more an occasion for object's taking place. On the other hand, it seems 3D printing technology is reduced to mere means; a simple intermediary, a copier of ideas. From that perspective the paper questioning the problem of action in ANT and search how action and interaction is distributed and how actors constitutes themselves as well as their actor-world.


Author(s):  
Tihomir Mitev

The additive manufacturing (or the popular 3D printing) is relatively new technology which opens new spaces for entrepreneurial imagination and promises next stage of the industrial revolution. It is creating three dimensional solid objects from a digital file. The printer transforms the file into a material object layer by layer, using different raw materials. Today, the additive manufacturing is successfully used in architecture, medicine and healthcare, light and heavy industries, education, etc. The paper analyses the roles of actors in manufacturing the objects. It starts with the Heideggerian questioning of technology (), searching for the causes of bringing into appearance of the 3D model. According to Heideggerian analysis the technology is represented as an ‘unveiling of the truth'. The paper suggests that the old understanding of matter as a thing-in-itself should be replaced by a new, flexible, fluid, concept of matter, which is more or less manipulable. The matter is no more an occasion for object's taking place. On the other hand, it seems 3D printing technology is reduced to mere means; a simple intermediary, a copier of ideas. From that perspective the paper questioning the problem of action in ANT and search how action and interaction is distributed and how actors constitutes themselves as well as their actor-world.


2020 ◽  
Vol 12 (7) ◽  
pp. 894-899
Author(s):  
Devendra Kumar Prajapati ◽  
Ravinder Kumar

Additive manufacturing (AM) is an advanced technique to fabricate a three-dimensional object while utilizing materials with minimal wastage to produce complex shape geometries. This technique has escalated practically as well as academically, resulting in a wide range of utility in the current global scenario to ease the manufacturing of complex and intricate objects with the use of various materials, depending upon the properties and availability of the same. Every industries wants to achieve the sustainability, easily can be possible through this manufacturing process. Due to the scope for a large number of design, material and processing combinations, a detailed outlook to how additive manufacturing can be optimized for a highly sustainable and standardized manufacturing practice needs to be assessed and understood. This paper discusses the core knowledge available regarding this manufacturing process and highlights the different processes related to this technique through review of various research papers. And also discuss the sustainability of important additive manufacturing process. Along with the fundamental analysis of this process, the paper also discusses the various attributes of the process and the growth with respect to the latest trends and techniques currently used in industries.


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