scholarly journals Independent Evaluation of Medical-Grade Bioresorbable Filaments for Fused Deposition Modelling/Fused Filament Fabrication of Tissue Engineered Constructs

Polymers ◽  
2018 ◽  
Vol 10 (1) ◽  
pp. 40 ◽  
Author(s):  
◽  
◽  
Keyword(s):  
Fused Deposition Modelling ◽  
Fused Filament Fabrication ◽  
Fused Deposition ◽  
Independent Evaluation ◽  
Medical Grade

scholarly journals A new algorithm for build time estimation for fused filament fabrication technologies

2016 ◽  
Vol 230 (12) ◽  
pp. 2214-2228 ◽  
Author(s):  
Zicheng Zhu ◽  
Vimal Dhokia ◽  
Stephen T Newman
Keyword(s):  
Time Estimation ◽  
Numerical Control ◽  
Accurate Estimation ◽  
Fused Deposition Modelling ◽  
Hybrid Manufacturing ◽  
Production Operation ◽  
Fused Filament Fabrication ◽  
Fused Deposition ◽  
Wide Range ◽  
Build Time

The manufacture of highly complex and accurate part geometries with reduced costs has led to the emergence of hybrid manufacturing technologies where varied manufacturing operations are carried out in either parallel or serial manner. One such hybrid process being currently developed is the iAtractive process, which combines additive (i.e. fused filament fabrication, which is sometimes called fused deposition modelling. However, the latter term is trademarked by Stratasys Inc. and cannot be used publicly without authorisation from Stratasys) and subtractive (i.e. computer numerical control machining) processes. In the iAtractive process production, operation sequencing of additive and subtractive operations is essential. This requires accurate estimation of production time, in which the fused filament fabrication build time is the determining factor. There have been some estimators developed for fused deposition modelling. However, these estimators are not applicable to hybrid manufacturing, particularly in process planning, which is a vital stage. This article addresses the characteristics of fused filament fabrication technologies and develops a novel and rigorous method for predicting build times. An analytical model was first created to theoretically analyse the factors that affect the part build time and was subsequently used to facilitate the design of test parts and experiments. The experimental results indicate that part volume, interaction of volume and porosity and interaction of height and intermittent factor have significant effects on build times. Finally, the estimation algorithm has been developed, which was subsequently evaluated and validated by applying a wide range of identified influential factors. The major advantage of the new proposed algorithm is its ability to estimate the build time based on simple geometrical parameters of a given part. The key factors that drive the algorithm can be directly obtained from part dimensions/drawings, providing an efficient and accurate way for fused filament fabrication time estimation. Test part evaluations and analysis have clearly demonstrated that estimation errors range from 0.1% to 13.5%, showing the validity, capability and significance of the developed algorithm and its applications to hybrid manufacture.

scholarly journals A 3D Printed, Constriction-Resistive Sensor for the Detection of Ultrasonic Waves

2021 ◽  
Keyword(s):  
Structural Health Monitoring ◽  
3D Printing ◽  
Health Monitoring ◽  
Low Cost ◽  
Ultrasonic Waves ◽  
Fused Deposition Modelling ◽  
Fused Filament Fabrication ◽  
Engineering Structures ◽  
Structural Health ◽  
Fused Deposition

Abstract. Ultrasonic waves, either bulk waves or guided waves, are commonly used for non-destructive evaluation, for example in structural health monitoring. Traditional sensors for detecting ultrasonic waves include metallic strain gauges and piezoelectric ceramics. Recently piezoresistive nanocomposites have emerged as a promising sensor with high sensing range. In this paper, a constriction-resistive based sensor made from a graphene reinforced PLA filament is developed using a fused deposition modelling 3D printing approach as a novel type of ultrasonic sensor for structural health monitoring purposes. The sensor is made of very low-cost and recyclable thermoplastic material, which is lightweight and can be either directly printed onto the surface of various engineering structures, or embedded into the interior of a structure via fused filament fabrication 3D printing. These characteristics make this sensor a promising candidate compared to the traditional sensors in detecting ultrasonic waves for structural health monitoring. The printed sensors can detect ultrasonic signals with frequencies around 200 kHz, with good signal-to-noise ratio and sensitivity. When deployed between two adjacent printed tracks , and exploiting a novel kissing-bond mechanism, the sensor is capable of detecting ultrasonic waves. Several confirmatory experiments were carried out on this printed sensor to validate the capability of the printed sensor for structural health monitoring.

scholarly journals Extrusion-Based 3D Printing of Microfluidic Devices for Chemical and Biomedical Applications: A Topical Review

Micromachines ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 374 ◽  
Author(s):  
Daniela Pranzo ◽  
Piero Larizza ◽  
Daniel Filippini ◽  
Gianluca Percoco
Keyword(s):  
Biomedical Applications ◽  
Microfluidic Devices ◽  
Research Topic ◽  
Point Of View ◽  
Fused Deposition Modelling ◽  
Fused Filament Fabrication ◽  
Fused Deposition ◽  
The World ◽  
Low Costs ◽  
Machine Structure

One of the most widespread additive manufacturing (AM) technologies is fused deposition modelling (FDM), also known as fused filament fabrication (FFF) or extrusion-based AM. The main reasons for its success are low costs, very simple machine structure, and a wide variety of available materials. However, one of the main limitations of the process is its accuracy and finishing. In spite of this, FDM is finding more and more applications, including in the world of micro-components. In this world, one of the most interesting topics is represented by microfluidic reactors for chemical and biomedical applications. The present review focusses on this research topic from a process point of view, describing at first the platforms and materials and then deepening the most relevant applications.

scholarly journals Entwicklung und Realisierung neuer Designs zur Nutzung als Knochenersatzmaterial mittels Fused-Deposition-Modelling-3D- Druck

2021 ◽  
Author(s):  
◽  
Jonas Neijhoft
Keyword(s):  
Tissue Engineering ◽  
Computer Aided Design ◽  
Fused Deposition Modelling ◽  
Fused Filament Fabrication ◽  
Fused Deposition ◽  
Computer Aided ◽  
Osteogene Differenzierung ◽  
Aided Design ◽  
Physikalische Eigenschaften

Die Therapie langstreckiger Knochendefekte stellt auch weiterhin eine große Herausforderung dar. Dies beruht unter anderem darauf, dass der therapeutische Goldstandard - die Verwendung von autogener Knochensubstanz aus dem Beckenkamm - neben der begrenzten Verfügbarkeit vor allem Komplikationen im Bereich der Entnahmestelle mit sich bringen kann. Es wurde bisher aber noch kein durchschlagendes Ergebnis in der Entwicklung neuer Scaffolds zum Einsatz bei langstreckigen Knochendefekten erreicht. Dies kann eine Vielzahl an Ursachen haben, die sich von der verwendeten Ausgangssubstanz, bis hin zum verwendeten Design erstrecken können. Neben dem Ausgangsmaterial spielen vor allem die Formgebung und physikalische Eigenschaften, wie Porosität und Mikroarchitektur, eine wichtige Rolle. Ein aktueller Ansatz zur Nutzung als alternatives Knochenersatzmaterial ist das Knochen-Tissue-Engineering. Hierbei werden körpereigene, knochen-regenerative Zellen mit einem dreidimensionalen Gerüststoff (Knochenersatzmaterial oder -scaffold) kombiniert und in den Knochendefekt implantiert. In dieser Arbeit wurde der Fokus auf die Designentwicklung eines neuen Kochenersatz-Scaffolds gelegt. Nach Vorbild schon vorgestellter Knochenersatzdesigns und unter Berücksichtigung einer Grundstruktur, die auch Phasen der Knochenheilung wie die Frakturhämatomausbreitung und initiale Nährstoffversorgung einbeziehen sollte, wurden mehrere Designs (Raster, Tempel, Zwiebel) entwickelt. Mithilfe des additiv extrusionsbasierten Schmelzschichtverfahrens (Fused Filament Fabrication) wurden die in Computer-Aided Design entworfenen Scaffolds realisiert. Dieser Ansatz beinhaltet, unter Verwendung des resorbierbaren und biokompatiblen Trägerpolymers Polylaktat, mehrstufige Designs, die kleine biologisch funktionelle Einheiten in eine tragende, kompressionsfeste Rahmenstruktur einbetten. Hierdurch entsteht einerseits die nötige mechanische Belastbarkeit und andererseits eine offene Architektur mit Poren, die Diffusion von Sauerstoff und Nährstoffen in die inneren Bereiche des Implantats ermöglicht. Es wurden verschiedene Designs entwickelt, gedruckt und mechanisch sowie in vitro in den Kernbereichen Zelladhäsion, Zellaktivität und osteogene Differenzierung nach Besiedelung mit Saos-2-Zellen charakterisiert. Ein weiterer Entwicklungsschritt stellte das Einführen eines neuartigen, innerhalb der Designs kompatiblen Baukastensystems dar. Hierdurch wird nicht nur die Anpassbarkeit an den Knochendefekt verbessert, es sind auch weitere Funktionen ergänzbar und die unterschiedlichen Designs untereinander kombinierbar. Die Ergebnisse dieser Dissertationsarbeit dienen als Basis für einen völlig neuen Ansatz von Knochenersatzmaterialien mit positiven biologischen sowie biophysikalischen Eigenschaften.

Evaluation of geometrical benchmark artifacts containing multiple overhang lengths fabricated using material extrusion technique

2020 ◽  
Vol 14 (3) ◽  
pp. 7296-7308
Author(s):  
Siti Nur Humaira Mazlan ◽  
Aini Zuhra Abdul Kadir ◽  
N. H. A. Ngadiman ◽  
M.R. Alkahari
Keyword(s):  
3D Model ◽  
Laser Scanner ◽  
Dimensional Accuracy ◽  
Fused Deposition Modelling ◽  
Layer By Layer ◽  
Fused Deposition ◽  
Layer Technique ◽  
Subtractive Manufacturing ◽  
Manufacturing Features ◽  
Layer Problem

Fused deposition modelling (FDM) is a process of joining materials based on material entrusion technique to produce objects from 3D model using layer-by-layer technique as opposed to subtractive manufacturing. However, many challenges arise in the FDM-printed part such as warping, first layer problem and elephant food that was led to an error in dimensional accuracy of the printed parts especially for the overhanging parts. Hence, in order to investigate the manufacturability of the FDM printed part, various geometrical and manufacturing features were developed using the benchmarking artifacts. Therefore, in this study, new benchmarking artifacts containing multiple overhang lengths were proposed. After the benchmarking artifacts were developed, each of the features were inspected using 3D laser scanner to measure the dimensional accuracy and tolerances. Based on 3D scanned parts, 80% of the fabricated parts were fabricated within ±0.5 mm of dimensional accuracy as compared with the CAD data. In addition, the multiple overhang lengths were also successfully fabricated with a very significant of filament sagging observed.

scholarly journals Current State and Challenges of Natural Fibre-Reinforced Polymer Composites as Feeder in FDM-Based 3D Printing

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2289
Author(s):  
Nishata Royan Rajendran Royan ◽  
Jie Sheng Leong ◽  
Wai Nam Chan ◽  
Jie Ren Tan ◽  
Zainon Sharmila Binti Shamsuddin
Keyword(s):  
Mechanical Properties ◽  
Natural Fibre ◽  
Critical Discussion ◽  
Fused Deposition Modelling ◽  
Preparation Methods ◽  
Fused Deposition ◽  
Current State ◽  
Future Challenges ◽  
Raster Angle ◽  
Fibre Reinforced Polymer

As one of the fastest-growing additive manufacturing (AM) technologies, fused deposition modelling (FDM) shows great potential in printing natural fibre-reinforced composites (NFRC). However, several challenges, such as low mechanical properties and difficulty in printing, need to be overcome. Therefore, the effort to improve the NFRC for use in AM has been accelerating in recent years. This review attempts to summarise the current approaches of using NFRC as a feeder for AM. The effects of fibre treatments, composite preparation methods and addition of compatibilizer agents were analysed and discussed. Additionally, current methods of producing feeders from NFRCs were reviewed and discussed. Mechanical property of printed part was also dependent on the printing parameters, and thus the effects of printing temperature, layer height, infill and raster angle were discussed, and the best parameters reported by other researchers were identified. Following that, an overview of the mechanical properties of these composites as reported by various researchers was provided. Next, the use of optimisation techniques for NFRCs was discussed and analysed. Lastly, the review provided a critical discussion on the overall topic, identified all research gaps present in the use of NFRC for AM processes, and to overcome future challenges.

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