Desktop Fused Deposition Modeling Research Articles

Challenges and Solutions for Cost-Effective and Practical Dental Cast Fabrication With a Desktop Fused Deposition Modeling (FDM) 3D Printer

Challenges and Solutions for Cost-Effective and Practical Dental Cast Fabrication With a Desktop Fused Deposition Modeling (FDM) 3D Printer

Design and Development of a Novel 3-D Printed External Fixation Device for Fracture Stabilization

BackgroundAn external fixator is an orthopaedic device used to stabilize long bone fractures after high energy trauma. These devices are external to the body and fixed to metal pins going into non-injured areas of bone. They serve a mechanical function to maintain length, prevent bending, and resist torque forces about the fracture area. The purpose of this manuscript is to describe a design and prototyping process creating a low-cost entirely 3-D printed external fixator for fracture stabilization of extremity fractures. The secondary objective of this manuscript is to facilitate future advancements, modifications, and innovations in this area of 3-D printing in medicine.MethodsThis manuscript describes the computer aided design process using desktop fused deposition modeling to create a 3-D printed external fixator system designed for fracture stabilization. The device was created using the orthopaedic goals for fracture stabilization with external fixation. However, special modifications and considerations had to be accounted for given the limitations of desktop fused deposition modeling and 3-D printing with plastic polymers.ResultsThe presented device accomplishes the goals of creating a construct that can be attached to 5.0 mm metal pins, allows for modularity in placement orientations, and facilitates adjustable lengths for fracture care. Furthermore, the device provides length stability, prevention of bending, and resists torque forces. The device can be printed on a desktop 3-D printer using standard low-cost polylactic acid filament. The print time is less than two days and can be completed on one print bed platform.ConclusionsThe presented device is a potential alternative for fracture stabilization. The concept of a desktop 3-D printed external fixator design and method of production allows for numerous diverse applications. This includes assisting areas with remote or limited access to advanced medical care and large-scale natural disasters or global conflicts where large volumes of fractures exceed the local medical supply chain capabilities. The presented device creates a foundation for future devices and innovations in this fracture care space. Further research is needed on mechanical testing and clinical outcomes with this design and initiative in fracture care before clinical application.

A Low-Cost Process for Fabricating Reinforced 3D Printing Thermoplastic Filaments.

Low-cost desktop-sized fused deposition modeling (FDM) printers have been widely embraced by small to large-scale institutions and individuals. To further enhance their utility and increase the range of materials that they can process, this work proposes a low-cost solution that adapts to low-cost desktop-sized extruders and enables them to fabricate filaments comprising a wide range of nonorganic reinforcing particles. This solution will fill a gap in the field, as low-cost fabrication techniques for reinforced filaments have been lacking. In the proposed solution, particles are heated and deposited on thermoplastic pellets to form a coating. Coated pellets are subsequently extruded using a low-cost desktop single-screw extruder. The effectiveness of the process is demonstrated by fabricating polylactic acid (PLA) filaments reinforced with two types of reinforcements, namely, dune sand and silicon carbide. Filaments' stiffness and strength were measured, and their microstructure along their lateral and longitudinal directions were investigated. Improvements in tensile strength (up to 8%) and stiffness (up to 4.5%) were observed, but at low reinforcement levels (less than 2 wt%). Results showed that the proposed process could be used to fabricate filaments with multiple types of particles. The produced filaments were successfully used to fabricate 3D parts using a commercial desktop FDM printer.

Utilizing ultrafast lasers for postprocessing to improve mechanical properties of 3D-printed parts

Recent advances in additive manufacturing technologies have already led to the wide-scale adoption of 3D-printed parts in the aerospace, medical, automotive, tooling, and electronics industries. The expansion in choice of materials that can be processed, in particular, using fused deposition modeling (FDM), selective laser sintering/melting, and stereolithography, and the steady advancements in dimensional accuracy control, have extended the range of applications beyond rapid prototyping. However, additive manufacturing still has considerable limitations compared to traditional and subtractive manufacturing processes. This work addresses limitations associated with the as-deposited surface roughness of 3D-printed parts. The effects of roughness-induced stress concentrations on the mechanical strength were studied, and ultrafast laser postprocessing was utilized to reduce the surface roughness of 3D-printed parts. The samples were manufactured using a commercial desktop FDM system and standard ASTM flat dogbone geometries. The samples were then postprocessed with a high-repetition-rate ultrafast Yb-fiber laser using a multi-layer scan approach. This novel postprocessing method enables high-efficiency material removal without inducing excessive thermal residual stresses into the material and, therefore, is suitable for postprocessing thermally sensitive materials, such as PLA and other polymers as well as parts with engineered porosity. In this work, we vary laser process parameters, such as average power and number of laser-processed layers, to achieve various levels of surface roughness. Values of tensile strength of the specimens were compared between 3D-printed samples featuring initial roughness and laser postprocessed samples with different values of surface roughness. The results indicate that the laser-processed samples exhibit an almost 10% increase in tensile strength depending on specific laser processing parameters.

Fused Deposition Modeling 3D Printing in Oral and Maxillofacial Surgery: Problems and Solutions.

Three-dimensional (3D) printing technology in medicine is one of the new and innovative technology for fabricating 3D models of complex anatomical structures that can be observed both visually and haptically. Patient-specific 3D models fabricated through this process are currently being used for various purposes, including surgical simulation, training, and medical education. Most of the personal use/low-end desktop 3D printers that are becoming widespread are fused deposition modeling (FDM) 3D printers. Compared to professional/high-end 3D printers, the price of the personal use/low-end desktop FDM 3D printer itself, filament, and running costs are lower; it can lower the economic bottleneck for introducing 3D printing technology into clinical practice, such as surgical simulation. With a desktop FDM 3D printer and a general-purpose PC, anyone can now rapidly fabricate 3D models on their own without having to rely on 3D printing labs and specialized technicians. However, it is also true that FDM 3D printers, due to their mechanical characteristics, encounter many difficulties and problems that emerge during the 3D printing process. Knowledge, know-how, and tips about FDM 3D printers have been introduced in various media, and it has become easy to know about them worldwide via the Internet. However, there has been no comprehensive technical review to date to produce osseous 3D models for use in oral and maxillofacial surgery. In this report, to create 3D models according to the characteristics of maxillofacial and oral surgery, we enable surgeons themselves to create 3D models smoothly by presenting ideas for CT scanning, points to note when exporting Digital Imaging and Communications in Medicine (DICOM) image data, how to create optimal stereolithography (STL) models, and problems and solutions for 3D printing.

Experimental and Thermal Analysis of Desktop FDM 3D Printers "Ender 3" and "CR-10S Pro" Hot Ends

Nowadays, the desktop 3D printers are common in computer aided manufacturing and widely used in multiple applications across homes, offices, and in several business sectors, etc. A wide variety of filaments like PLA, ABS, PETG, TPU, etc. are now being used in Fused Deposition Modeling (FDM). These filaments require different temperatures to print. FDM is a process in which a material in its filament form is melted and deposited layer by layer to form the required object. The hot end of a printer plays a crucial role in the melting of these filaments for printing. It is a major component of a 3D printer, where the filament is brought to a semi-solid state, to extrude and deposit the filament in layers. In this research study, the hot end of "Ender 3" and "CR-10S Pro" are modeled using Computer Aided Designing software, and thermal analysis using Finite Element Analysis, is carried out by applying the maximum printing temperature of PLA for the two printer hot ends. To optimize the problem of wide temperature gradient which often results in clogs and jams across the hot end, the design of heat sink is modified to maximize heat dissipation. Alongside, the simulation result is also compared with manual experimental readings.

Multiscale sterilizable 3D printed auricular templates to guide cartilaginous framework sizing and sculpture during autologous microtia reconstruction

SummaryMicrotia reconstruction using autologous costal cartilage can be one of the most challenging tasks in reconstructive surgery. An intraoperative guide using 2-dimentional drawing of the contralateral ear on an x-ray film remains the current standard of care. In this paper, we present the use of computer-aided design and desktop 3D printing to fabricate low cost, sterilizable auricular carving templates to serve as a peri-operative reference for microtia reconstruction. The design was made as a single component which incorporated the usual anatomic reference points of the ear based on Nagata technique as a Stereo-lithography file format (. STL) for 3D printing. The templates were created in sizes ranging from 55 mm to 70 mm with a 2 mm increment with an average production cost of 0.26 US dollars per material per template and about 4.5 US dollars for the whole set. Individual templates were then 3D-printed using a thermoplastic polyurethane (TPU 95A) semiflexible filament on a desktop fused deposition modeling, Ultimaker 2 + 3D printer. The produced template tolerated the sterilization process with no structural changes as compared to its pre-sterilization condition. In conclusion, we present cost-effective, sterilizable, multiscale auricular templates to guide the pre- and intra-operative carving of the cartilaginous framework during microtia reconstruction with more accuracy in a time efficient manner, thereby overcoming the drawbacks of using the traditional x-ray film. The templates are readily accessible and sharable for free through open-source software and can be directly 3D-printed using an affordable desktop 3D printer.

3D printer particle emissions: Translation to internal dose in adults and children

Desktop fused deposition modeling (FDM®) three-dimensional (3D) printers are becoming increasingly popular in schools, libraries, and among home hobbyists. FDM® 3D printers have been shown to release ultrafine airborne particles in large amounts, indicating the potential for inhalation exposure and consequent health risks among FDM® 3D printer users and other room occupants including children. These particles are generated from the heating of thermoplastic polymer feedstocks during the FDM® 3D printing process, with the most commonly used polymers being acrylonitrile butadiene styrene (ABS) and poly-lactic acid (PLA). Risk assessment of these exposures demands estimation of internal dose, especially to address intra-human variability across life stages. Dosimetry models have proven to effectively translate particle exposures to internal dose metrics relevant to evaluation of their effects in the respiratory tract. We used the open-access multiple path particle dosimetry (MPPD v3.04) model to estimate inhaled particle deposition in different regions of the respiratory tract for children of various age groups from three months to eighteen years old adults. Mass concentration data for input into the MPPD model were calculated using particle size distribution and density data from experimental FDM® 3D printer emissions tests using both ABS and PLA. The impact of changes in critical parameters that are principal determinants of inhaled dose, including: sex, age, and exposure duration, was examined using input parameter values available from the International Commission on Radiological Protection. Internal dose metrics used included regional mass deposition, mass deposition normalized by pulmonary surface area, surface area of deposited particles by pulmonary surface area, and retained regional mass. Total mass deposition was found to be highest in the 9-year-old to 18-year-old age groups with mass deposition by pulmonary surface area highest in 3-month-olds to 9-year-olds and surface area of deposited particles by pulmonary surface area to be highest in 9-year-olds. Clearance modeling revealed that frequent 3D printer users are at risk for an increased cumulative retained dose.

Establishing a Cost-Effective 3-Dimensional Printing Laboratory for Anatomical Modeling and Simulation: An Institutional Experience.

Three-dimensional (3D) printing is rapidly growing in popularity for anatomical modeling and simulation for medical organizations across the world. Although this technology provides a powerful means of creating accurately representative models of anatomic structures, there remains formidable financial and workforce barriers to understanding the fundamentals of technology use, as well as establishing a cost- and time-effective system for standardized incorporation into a workflow for simulator design and anatomical modeling. There are many factors to consider when choosing the appropriate printer and accompanying software to succeed in accomplishing the desired goals of the executing team. The authors have successfully used open-access software and desktop fused deposition modeling 3D printing methods to produce more than 1000 models for anatomical modeling and procedural simulation in a cost-effective manner. It is our aim to share our experience and thought processes of implementing 3D printing into our anatomical modeling and simulation workflow to encourage other institutions to comfortably adopt this technology into their daily routines.

A Low-Cost 3D-Printed Tool with Multiaxial/Angular Vessel Orientation for Microvascular Anastomosis Training.

Background:Microsurgical anastomosis is a technically demanding skill. The most difficult part of the learning process was in achieving the necessary orientation and dexterity. In this project, we adopted computer-aided design and desktop 3D-printing in the development of an affordable training model with different levels of vessel orientation and angulation.Methods:The training model was designed using CAD software (Rhino3D). The models were then 3D-printed with a thermoplastic polyurethane (TPU 95A) semiflexible filament on a desktop fused deposition modeling, Ultimaker 2 + 3D printer.Results:The printed training tool was assembled by fitting the ball-and-socket mechanism between two parts having an overall round table top with integrated vascular clamps. Trial with synthetic and nonliving animal blood vessels shows the utility of the clamps in holding the vessels within the working space. By rotating the top part, a multiaxial vessel orientation from 0 to 360 degrees was achieved. The top part was also capable of multiangular orientation of the vessels (±30 degrees) regardless of its axial orientation during vessel anastomosis. For the 3D-printing process, the average printing time was about 3.5 hours with a cost of 1.3$ per material.Conclusions:The utility of desktop 3D printing represents an affordable modality in microsurgical training. The designed model is capable of providing a trainee with multiaxial and multiangular vessel orientation during the anastomosis process. To our knowledge, the adoption of this technology in the field of microsurgery training has never been investigated before.

3D printed porous PLA/nHA composite scaffolds with enhanced osteogenesis and osteoconductivity in vivo for bone regeneration

Repair and regeneration of large bone defects is still a challenge, especially for defects which are the irregular and complex. Three-dimension (3D) printing, as an advanced fabrication technology, has been received considerable attentions due to its high precision, customized geometry and personalization. In this study, 3D porous polylactic acid/nano hydroxyapatite (PLA/nHA) composite scaffolds with enhanced osteogenesis and osteoconductivity were successfully fabricated by desktop fused deposition modeling technology. Morphological, composition and structural analysis revealed that nHA was successfully introduced into the PLA system and homogeneously dispersed in the printed PLA/nHA scaffolds. In vitro antibacterial experiment confirmed that the printed porous PLA/nHA scaffolds have good ability for loading and releasing vancomycin and levofloxacin. Meanwhile, MG-63 cells were used to evaluate the cytocompatibility of printed porous PLA/nHA scaffolds by proliferation and cellular morphological analysis. In addition, rabbit model was established to evaluate the osteogenesis and osteoconductivity of printed PLA/nHA scaffolds. All these results suggested that the 3D printed PLA/nHA scaffolds have great potential for repairing and regeneration of large bone defects.

Three-dimensional printed embedded channel–based resistive strain sensor: Fabrication and experimental characterization

This work explores the feasibility of commercially available elastic filament and desktop fused deposition modeling three-dimensional printing as a simple and cost-effective route to develop flexible sensors. The fabricated sensor consists of a three-dimensional printed flexible substrate with embedded U-shaped channels that are filled with Galinstan (Ga 68.5% In 21.5% Sn 10%) liquid metal conductor. When the sensor is strained, the cross-sectional area of the channels decreases causing a reduction in the conducting area and, therefore, a change in resistance. First, sensors measuring approximately 2100 μm by 200 μm are fabricated. Results demonstrate gauge factors of approximately 2.1 at 38.8% strain with high linearity and little hysteresis. In addition, smaller strain sensors, measuring approximately 696 µm by 203 µm, are fabricated with gauge factors of nearly 1.0 at 13.2% strain. Results show that substrate relaxation plays an essential role in determining the functionality of these sensors. The Mullins effect largely influences the recovery properties of the rubber-like sensor substrate. This leads to a noticeable relaxation in the substrate during cyclic loading. The results demonstrate the potential of commercially available fused deposition modeling three-dimensional printing technology and filaments to produce complex designs and sensor platforms.

Causes of Desktop FDM Fabrication Failures in an Open Studio Environment

The usage phase often dominates the lifetime environmental impact of energy and material consuming products. Improper human behaviors could increase the environmental impacts during the use stage of the product’s life cycle. The use phase of desktop fused deposition modeling (FDM) printers involves large energy and material consumption. In university makerspaces, many novices choose to use desktop FDM printers because of its easy operation, but novices often make improper design and operation decisions. The human errors increase the fabrication failures leading to higher material and energy consumption. Therefore, human behaviors should be investigated in order to identify the causes of fabrication failures in an open studio environment. Three types of failure causes are studied, which are designer error, operator error and machine error. In this research, computer-aided design (CAD) models, printing settings, user experience information and printing results were tracked and analyzed. In addition, the energy and material consumption were recorded from the printings. These data are analyzed to identify the key factors affecting printing failure rates and to improve the sustainability and efficiency of desktop FDM. From the collected data, a failure rate of 41.1% was observed. The failures caused by human error accounted for 26.3% of the total prints, which shows that human behaviors could influence the environmental impacts of FDM. For the factors impacting failure rates, user’s experience level and printing parameters were analyzed. We found that that experience did not result in higher expertise or lower failure rates.

Energy simulation of the fused deposition modeling process using machine learning approach

Fused deposition modeling (FDM) is an additive manufacturing process using a nozzle to squeeze filaments of thermoplastic materials to create layers. At current research state, the energy performance evaluation of FDM processes is mainly realized by means of experimental methods, and a simulation-based approach is still absent and called for. As a promising tool for analyzing and constructing data, machine learning approaches have been widely implemented in energy performance analysis of different engineering areas but not FDM. Hence, this paper aims at this research gap and introduces the application of random forest algorithm, which is a typical inductive machine learning approach, for predicting the energy consumption as well as the power curve imitation of a desktop FDM system. In addition, an experimental validation is carried out.

Uncertainty and Variability of Energy and Material Use by Fused Deposition Modeling Printers in Makerspaces

SummaryDesktop‐grade fused deposition modeling (FDM) printers are popular because of compact sizes and affordable prices. If we are moving toward a future where desktop FDM printers are in every school and office, like conventional printers, then these machines will consume a large amount of energy and material. However, it is very difficult to evaluate the environmental impacts of FDM printers since there are so many different brands and types of printers using different raw materials under different scenarios. This study uses data from two different printing sites to evaluate the scenario and parameter uncertainty and variability in energy and material balances for FDM printers. Data from the two makerspaces provide insight into the material and energy consumption data using polylactic acid and acrylonitrile butadiene styrene (ABS) with four types of printers. The use of actual performance data allowed for the additional study of scrap ratio. Regressions provide insight into predictive factors for energy and material consumption. Monte Carlo simulations show the range of energy life cycle inventory values for the desktop‐grade FDM printers. From the regressions, Type A Pro was the most energy‐intensive machine. For material waste, an open‐access makerspace using ABS was associated with higher scrap ratio. Regression analysis indicates that the rate of material usage is not a strong predictor of waste rates. The amount of waste generated across both sites indicates that more ubiquitous access to FDM printing may create a significant addition to the waste stream.

Orientation field guided line abstraction for 3D printing

This paper focuses on printing a 2D color image by using a desktop fused deposition modeling (FDM) 3D printer. A fully automatic framework is presented to convert a 2D image into a non-photorealistic line drawing which is suitable for 3D printing. Firstly, an image is partitioned into a moderate number of regions, and contours of these regions are extracted to deliver the high level abstraction of the image. The contour lines are further refined by taking into consideration the restrictions of 3D printing. Next, an orientation field based on the contours and feature lines at a finer level is computed to guide the placement of streamlines. The distances between streamlines are carefully controlled such that the density respects the pixel intensity values. Finally, the resulting streamlines are converted into printing paths and printed by using filaments with specified colors. Experimental results show the feasibility and efficacy of our method on portraying a given image by using a few of 3D printable non-intersecting lines while preserving features and tone variation in the image.

Fused Deposition Modelling based Printing of Full Complement Bearings

Additive manufacturing, the process of building components layer by layer offers great flexibility and freedom in design and manufacture. Over the advancements in past a few years, application of this technology has changed from mere prototyping to production of functional components. Though most of the functional components made are parts for the assembly. In this study an attempt has been made to produce a movable component- ball bearing in a single go which otherwise require assembly. A low cost desktop fused deposition modeling (FDM) printer has been utilized to print in multiple materials. The bearing was printed using PLA, ABS and Nylon 66. Surface characterization such as area surface roughness and Shore D hardness of the printed materials have been measured and compared. It was found that FDM has the potential to fabricate complicated movable parts in single step.

How Surface Roughness Performance of Printed Parts Manufactured by Desktop FDM 3D Printer with PLA+ is Influenced by Measuring Direction

Design work related to the implementation of new elements requires the use of 3D CAD modelling techniques and rapid prototyping, which makes it possible to accelerate the deployment of new solutions significantly. In this paper, six successful assembly parts are 3D printed with advanced polylactic acid (PLA+) using the fused deposition modeling (FDM) method and are expressed by the arithmetic mean surface roughness, Ra. The surface roughness was measured in three different angular directions 0°, 45° and 90° during the investigation along with various independent process parameters of nozzle diameter (0.5, 0.3, 0.2 mm), layer height (0.3, 0.2, 0.1 mm) and other dependent variables, i.e., nozzle temperature (220°C), print speed (30 mm/s) and infill density (0%). Experimental results show that nozzle diameter and layer height play a major role in terms of part quality finish, build time and ultimately part cost. Nozzle diameter and a layer height of 0.3 mm and 0.1 mm, respectively, represent the optimal manufacturing process parameters that can be selected. The surface roughness behaviour does not change and remains relatively constant and follows a similar trend with minor variations for both 45° and 90° measuring angle. Whereas, the surface roughness values are susceptible to 0° measuring direction to the build orientation as compared to other angles.

Characterization of chemical contaminants generated by a desktop fused deposition modeling 3-dimensional Printer

ABSTRACTPrinting devices are known to emit chemicals into the indoor atmosphere. Understanding factors that influence release of chemical contaminants from printers is necessary to develop effective exposure assessment and control strategies. In this study, a desktop fused deposition modeling (FDM) 3-dimensional (3-D) printer using acrylonitrile butadiene styrene (ABS) or polylactic acid (PLA) filaments and two monochrome laser printers were evaluated in a 0.5 m3 chamber. During printing, chamber air was monitored for vapors using a real-time photoionization detector (results expressed as isobutylene equivalents) to measure total volatile organic compound (TVOC) concentrations, evacuated canisters to identify specific VOCs by off-line gas chromatography-mass spectrometry (GC-MS) analysis, and liquid bubblers to identify carbonyl compounds by GC-MS. Airborne particles were collected on filters for off-line analysis using scanning electron microscopy with an energy dispersive x-ray detector to identify elemental constituents. For 3-D printing, TVOC emission rates were influenced by a printer malfunction, filament type, and to a lesser extent, by filament color; however, rates were not influenced by the number of printer nozzles used or the manufacturer's provided cover. TVOC emission rates were significantly lower for the 3-D printer (49–3552 µg h−1) compared to the laser printers (5782–7735 µg h−1). A total of 14 VOCs were identified during 3-D printing that were not present during laser printing. 3-D printed objects continued to off-gas styrene, indicating potential for continued exposure after the print job is completed. Carbonyl reaction products were likely formed from emissions of the 3-D printer, including 4-oxopentanal. Ultrafine particles generated by the 3-D printer using ABS and a laser printer contained chromium. Consideration of the factors that influenced the release of chemical contaminants (including known and suspected asthmagens such as styrene and 4-oxopentanal) from a FDM 3-D printer should be made when designing exposure assessment and control strategies.

Low Cost 3D Printed Biosensor Arrays for Biomedical Diagnostics

Development and fabrication of bioanalytical devices by 3D printing offers revolutionary new routes to low cost clinical diagnostic devices for molecular measurements. Relevant to future protein-based cancer diagnostics, we describe here our development of prototype protein immunoarray devices using desktop Fused Deposition Modeling (FDM) and stereolithographic 3D printers. All these system feature sensitive electro-optical detection by a method called electrochemiluminescence (ECL). Our first 3D-printed immunoarray features screen-printed sensors in which manual manipulations enable gravity flow reagent delivery for measurement of 3 proteins at detection limits of 0.3 to 0.5 pg/mL. ECL detection is achieved in an open channel on integrated disposable screen-printed sensor elements. We then address the issue of printing and processing optically clear plastic using a stereolithographic printer to build a closed ECL detection chamber. Finally, we describe a prototype 3D-printed microprocessor-controlled enclosed microfluidic ECL immunoarray featuring reagent reservoirs, micropumps and clear plastic detection chamber with printed nanowells for ECL emission.