Innovative approaches to designing and manufacturing a prosthetic thumb

2020 ◽  
pp. 030936462094971 ◽  
Author(s):  
Branko Štefanovič ◽  
Monika Michalíková ◽  
Lucia Bednarčíková ◽  
Marianna Trebuňová ◽  
Jozef Živčák
Keyword(s):  
Additive Manufacturing ◽  
3D Scanning ◽  
Metacarpal Bone ◽  
Point Of View ◽  
Dominant Hand ◽  
Fused Filament Fabrication ◽  
Conventional Methods ◽  
Manufacturing Technologies ◽  
The Right ◽  
Manufacturing Time

Case description: Conventional methods for producing custom prosthetic fingers are time-consuming, can be uncomfortable for the patient, and require a skilled prosthetist. The subject was a 40-year-old male with congenital absence of the thumb and related metacarpal bone on the right non-dominant hand, anomaly of the lengths of individual upper limb segments, and contracture of the elbow joint. This hand presentation made it impossible for him to perform thumb opposition, which is a very important function for common daily activities. Objective: The goal was to design an individual passive thumb prosthesis using free open-source software, 3D scanning technology, and additive manufacturing methods (i.e., fused filament fabrication). Study design: Case report. Treatment: Artificial thumb prostheses with two types of bases and fastening interfaces were designed and manufactured. One combination was chosen as the best alternative. Outcomes: The shape, positioning, firmness, and fastening of the prosthesis were compliant enough for the patient to be able to hold objects with his healthy fingers and artificial thumb. This innovative approach to fabrication of a custom thumb prosthesis provided considerable advantages in terms of custom sizing, manufacturing time, rapid production, iteration, comfort, and costs when compared to conventional methods of manufacturing a hand prosthesis. Conclusion: The methodology of designing and manufacturing a prosthetic thumb using 3D scanning and additive manufacturing technologies have been demonstrated to be adequate from a practical point of view. These technologies show potential for use in the practice of prosthetics.

scholarly journals Additive Manufacturing of Ti-Based Intermetallic Alloys: A Review and Conceptualization of a Next-Generation Machine

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4317
Author(s):  
Thywill Cephas Dzogbewu ◽  
Willie Bouwer du Preez
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
Additive Manufacturing ◽  
Complex Geometries ◽  
Intermetallic Alloys ◽  
Tial Alloys ◽  
Conventional Methods ◽  
Manufacturing Technologies ◽  
In Situ Heat Treatment

TiAl-based intermetallic alloys have come to the fore as the preferred alloys for high-temperature applications. Conventional methods (casting, forging, sheet forming, extrusion, etc.) have been applied to produce TiAl intermetallic alloys. However, the inherent limitations of conventional methods do not permit the production of the TiAl alloys with intricate geometries. Additive manufacturing technologies such as electron beam melting (EBM) and laser powder bed fusion (LPBF), were used to produce TiAl alloys with complex geometries. EBM technology can produce crack-free TiAl components but lacks geometrical accuracy. LPBF technology has great geometrical precision that could be used to produce TiAl alloys with tailored complex geometries, but cannot produce crack-free TiAl components. To satisfy the current industrial requirement of producing crack-free TiAl alloys with tailored geometries, the paper proposes a new heating model for the LPBF manufacturing process. The model could maintain even temperature between the solidified and subsequent layers, reducing temperature gradients (residual stress), which could eliminate crack formation. The new conceptualized model also opens a window for in situ heat treatment of the built samples to obtain the desired TiAl (γ-phase) and Ti3Al (α2-phase) intermetallic phases for high-temperature operations. In situ heat treatment would also improve the homogeneity of the microstructure of LPBF manufactured samples.

Green Material for Fused Filament Fabrication

2020 ◽  
pp. 1-27 ◽  
Author(s):  
Mastura Mohammad Taha ◽  
Ridhwan Jumaidin ◽  
Nadlene M. Razali ◽  
Syahibudil Ikhwan Abdul Kudus
Keyword(s):  
Additive Manufacturing ◽  
Composite Materials ◽  
Manufacturing Process ◽  
Extrusion Process ◽  
Fused Filament Fabrication ◽  
Green Material ◽  
Additive Manufacturing Technology ◽  
Green Materials ◽  
Composites Materials ◽  
The Right

Fused filament fabrication (FFF) has been developed in additive manufacturing technology as a fast and simple manufacturing process in product design. Advantage of the process such as flexibility in terms of the materials employment has attracted many researchers to develop new materials for the feed stock filament in the heat extrusion process of FFF. Green materials or bio-composites materials have been found in FFF and successfully commercialized in the market. However, a deep research should have been performed prior the application because of the unique characteristics of the material itself. The challenge for the researchers to develop bio-composite materials as the filament in FFF technology is to determine the right composition of the composites with the right thermal, mechanical, and rheological properties. Therefore, in this study, a review has been conducted to highlight the important requirements of the process and materials. Green materials such as bio-composites have a great potential in the FFF technology and could improve the sustainability impact.

scholarly journals A 3D weaving infill pattern for fused filament fabrication

2021 ◽  
Author(s):  
Yuan Yao ◽  
Cheng Ding ◽  
Mohamed Aburaia ◽  
Maximilian Lackner ◽  
Lanlan He
Keyword(s):  
Additive Manufacturing ◽  
Three Dimensional ◽  
Layer By Layer ◽  
Fused Filament Fabrication ◽  
Repetitive Structure ◽  
Mechanical Linkage ◽  
Manufacturing Technologies ◽  
Dimensional Object ◽  
Anisotropy Of Mechanical Properties ◽  
3D Weaving

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%.

scholarly journals Geometric Modeling of Cellular Materials for Additive Manufacturing in Biomedical Field: A Review

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Gianpaolo Savio ◽  
Stefano Rosso ◽  
Roberto Meneghello ◽  
Gianmaria Concheri
Keyword(s):  
Tissue Engineering ◽  
Additive Manufacturing ◽  
Geometric Modeling ◽  
Solid Freeform Fabrication ◽  
Cellular Materials ◽  
Point Of View ◽  
Porous Scaffolds ◽  
Freeform Fabrication ◽  
Geometric Point ◽  
Manufacturing Technologies

Advances in additive manufacturing technologies facilitate the fabrication of cellular materials that have tailored functional characteristics. The application of solid freeform fabrication techniques is especially exploited in designing scaffolds for tissue engineering. In this review, firstly, a classification of cellular materials from a geometric point of view is proposed; then, the main approaches on geometric modeling of cellular materials are discussed. Finally, an investigation on porous scaffolds fabricated by additive manufacturing technologies is pointed out. Perspectives in geometric modeling of scaffolds for tissue engineering are also proposed.

scholarly journals Processing of Sr2+ Containing Poly L-Lactic Acid-Based Hybrid Composites for Additive Manufacturing of Bone Scaffolds

2020 ◽  
Vol 7 ◽  
Author(s):  
Priscila Melo ◽  
Raasti Naseem ◽  
Ilaria Corvaglia ◽  
Giorgia Montalbano ◽  
Carlotta Pontremoli ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Additive Manufacturing ◽  
Hybrid Composites ◽  
Homogeneous Distribution ◽  
Fused Filament Fabrication ◽  
Rheological Characterization ◽  
Biodegradable Composite ◽  
Manufacturing Technologies

Biodegradable composite materials represent one of the major areas of investigation for bone tissue engineering due to their tuneable compositional and mechanical properties, which can potentially mimic those of bone and potentially avoid the removal of implants, mitigating the risks for the patient and reducing the overall clinical costs. In addition, the introduction of additive manufacturing technologies enables a strict control over the final morphological features of the scaffolds. In this scenario, the optimisation of 3D printable resorbable composites, made of biocompatible polymers and osteoinductive inorganic phases, offers the potential to produce a chemically and structurally biomimetic implant, which will resorb over time. The present work focuses on the development and process optimisation of two hybrid composite filaments, to be used as feedstock for the fused filament fabrication 3D printing process. A Poly L-lactic acid matrix was blended with either rod-like nano-hydroxyapatite (nano-HA) or nanoparticles of mesoporous bioactive glasses, both partially substituted with strontium (Sr2+), due to the well-known pro-osteogenic effect of this ion. Both inorganic phases were incorporated into Poly L-lactic acid using an innovative combination of processes, obtaining a homogeneous distribution throughout the polymer whilst preserving their ability to release Sr2+. The filament mechanical properties were not hindered after the incorporation of the inorganic phases, resulting in tensile strengths and moduli within the range of cancellous bone, 50 ± 10 MPa and 3 ± 1 GPa. Finally, the rheological characterization of the hybrid composites indicated a shear thinning behaviour, ideal for the processing with fused filament fabrication, proving the potential of these materials to be processed into 3D structures aiming bone regeneration.

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 Additive manufacturing – digitally changing the global business landscape

2019 ◽  
Vol 28 (2) ◽  
pp. 174-188 ◽  
Author(s):  
Christina Öberg
Keyword(s):  
Supply Chain ◽  
Additive Manufacturing ◽  
Design Methodology ◽  
Emerging Technology ◽  
Point Of View ◽  
Power Dependence ◽  
Power Struggle ◽  
Global Business ◽  
Content Type ◽  
Manufacturing Technologies

Purpose Additive manufacturing, that is, layer-based manufacturing technologies, is thought to change supply chain operations from global to local, while also affecting design processes and product structures. As this transformation happens, a power struggle among various actors relating themselves to additive manufacturing has emerged. The purpose of this paper is to discuss and explain the development of additive manufacturing from a power dependence point of view. Design/methodology/approach The paper is based on data collected from a number of seminars hosting a total of 620 industry experts representing 102 companies in the area, and reflecting every step of the supply chain. Findings The paper points out how measures to deal and create power imbalances occur also related to indirect parties, and how the disruptive character of the supply chain leads to exercised power. Originality/value The power struggle provides new insights into how an emerging technology is realised and the effect of protectionism on such attempts. Specifically related to additive manufacturing, the paper illustrates the business side from various actors’ point of view, which adds to technological perspectives on additive manufacturing, as well as studies viewing the supply chain from a bird’s-eye perspective.

scholarly journals AHP method to determine the optimal technological variant for maxillofacial implant fabrication

2018 ◽  
Vol 178 ◽  
pp. 03012
Author(s):  
Luciana Laura Dincă ◽  
Alexandra Banu ◽  
Aurelian Vişan ◽  
Nicolae Ionescu
Keyword(s):  
Additive Manufacturing ◽  
Mechanical Strength ◽  
Technological Process ◽  
Clinical Case ◽  
Metallic Materials ◽  
Optimal Process ◽  
Ahp Method ◽  
Materials Used ◽  
Manufacturing Technologies ◽  
The Right

The paper describes different technologies for manufacturing maxillofacial implant. By using the AHP method the AM, the direct manufacturing technology SLM is the optimal process. Technological variants for obtaining a maxillofacial implant that replaces the right zygomatic bone and a part of maxilla, based on a real clinical case are presented. Starting from the possibility of processing the biocompatible metallic materials used in the oral and maxillofacial technique, it is possible to classify the technological process variants in procedures that use and do not use additive manufacturing technologies. The aim of this paper is to show how important it is to select the optimal technological process in obtaining a maxillofacial implant. It has been analyzed the technological processes of achieving the maxillofacial implant, both those which use the additive manufacturing technologies and those which do not use such technologies, highlighting not only the benefits but also their limits. Based on criteria such as: mechanical strength, porosity, roughness, accuracy, anchorage, time and cost, by using the AHP method, it is possible to choose the optimal technological process for achieving the maxillofacial implant.

scholarly journals An Innovative Approach on Directed Energy Deposition Optimization: A Study of the Process Environment’s Influence on the Quality of Ti-6Al-4V Samples

2020 ◽  
Vol 10 (12) ◽  
pp. 4212
Author(s):  
Alessandro Carrozza ◽  
Alberta Aversa ◽  
Federico Mazzucato ◽  
Mariangela Lombardi ◽  
Sara Biamino ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Environmental Factors ◽  
Grain Morphology ◽  
Point Of View ◽  
Gas System ◽  
Columnar Grain ◽  
Directed Energy ◽  
Manufacturing Technologies ◽  
Blown Powder ◽  
Process Atmosphere

Blown powder additive manufacturing technologies are not restricted to the use of a process chamber. This feature allows to build larger components with respect to conventional powder bed processes. This peculiarity is mostly promising for manufacturing large components or repairing/rebuilding parts of large systems. The main downside of using an open environment, even if a protective shielding gas system is adopted, is the lack of control of process atmosphere. This is particularly critical for titanium alloys which are very sensitive to oxygen/nitrogen pick-up; they have a detrimental effect on ductility, by causing embrittlement and possibly leading to the formation of cracks. It is then important to address how environmental factors, such as process atmosphere and platform temperature, impact not only on the processability but also on the final component properties, both from a compositional and mechanical point of view. The correlations between these environmental factors and microstructure, interstitials content, grain size, and hardness were investigated. Moreover, the Hall–Petch equation was then adopted to additive manufacturing microstructures, characterized by a columnar grain morphology, and used to further investigate the relationship intercurring between grains and hardness and how different microstructures might influence this correlation.

scholarly journals Effects of Two Melt Extrusion Based Additive Manufacturing Technologies and Common Sterilization Methods on the Properties of a Medical Grade PLGA Copolymer

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 572
Author(s):  
Marion Gradwohl ◽  
Feng Chai ◽  
Julien Payen ◽  
Pierre Guerreschi ◽  
Philippe Marchetti ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Additive Manufacturing ◽  
Ethylene Oxide ◽  
Medical Devices ◽  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Fused Filament Fabrication ◽  
Scanning Calorimetry ◽  
Manufacturing Technologies ◽  
Medical Grade

Although bioabsorbable polymers have garnered increasing attention because of their potential in tissue engineering applications, to our knowledge there are only a few bioabsorbable 3D printed medical devices on the market thus far. In this study, we assessed the processability of medical grade Poly(lactic-co-glycolic) Acid (PLGA)85:15 via two additive manufacturing technologies: Fused Filament Fabrication (FFF) and Direct Pellet Printing (DPP) to highlight the least destructive technology towards PLGA. To quantify PLGA degradation, its molecular weight (gel permeation chromatography (GPC)) as well as its thermal properties (differential scanning calorimetry (DSC)) were evaluated at each processing step, including sterilization with conventional methods (ethylene oxide, gamma, and beta irradiation). Results show that 3D printing of PLGA on a DPP printer significantly decreased the number-average molecular weight (Mn) to the greatest extent (26% Mn loss, p < 0.0001) as it applies a longer residence time and higher shear stress compared to classic FFF (19% Mn loss, p < 0.0001). Among all sterilization methods tested, ethylene oxide seems to be the most appropriate, as it leads to no significant changes in PLGA properties. After sterilization, all samples were considered to be non-toxic, as cell viability was above 70% compared to the control, indicating that this manufacturing route could be used for the development of bioabsorbable medical devices. Based on our observations, we recommend using FFF printing and ethylene oxide sterilization to produce PLGA medical devices.

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