Deposition Modeling 3D Printing Technique Research Articles

Experimental study on mechanical properties of FDM 3D printed polylactic acid fabricated parts using response surface methodology

The purpose of this study is to examine the mechanical properties of components produced through the Response Surface Methodology for polylactic acid, utilizing the Fused Deposition Modeling 3D printing technique. Polylactic acid is a commonly employed biodegradable polymer, making it a desirable substance for diverse applications. This study involves carrying out experiments to vary process printing parameters like layer height or thickness, part orientation, and infill density. The values of these parameters were obtained using a Response Surface Methodology Box–Behnken experimental design. The mechanical performance of the 3D Printed polylactic acid fabricated was assessed by evaluating their flexural and tensile strength. The test samples for measuring tensile and flexural strength are fabricated according to American Society for Testing and Material standards. The findings suggest that higher strength is achieved when using increased layer height and infill levels. The experimental results indicated that specimens with a filling ratio of 80% exhibited greater tensile strength, while the flexural strength of samples with 50% infill was observed to be higher. Regression analyses and multi-optimization techniques were employed to predict the experimental results. This study provides valuable insights that can significantly impact various industries. Our research on the complex interactions between process variables and mechanical properties has major implications for improving high-strength component manufacturing. As demand for dependable and efficient 3D-printed materials rises, our discoveries improve material design and manufacturing methods, making a significant contribution to the field.

3D printed sequence-controlled copolyimides with high thermal and mechanical performance

Inadequate heat resistance and mechanical property limited the application of 3D printed polymer parts in aerospace industry. To address this restriction, a kind of sequence-controlled copolyimides with both amorphous segment and crystalline segment, suitable for fused deposition modeling 3D printing technique were designed and synthesized. The effect of content and distribution of crystalline segment on melt fluidity and crystallization behavior was disclosed. It was found that copolyimide with crystalline segment only distributed in the end of backbone exhibited good melt fluidity and slow crystallization rate. Microstructure change of the corresponding copolyimide during 3D printing and thermal annealing was revealed. Due to slow crystallization rate of copolyimide, no crystals formed during 3D printing. Thus, the diffusion and entanglement of polymer chain at interface were guaranteed. Thermal annealing at 350 °C facilitated diffusion and arrangement of polymer chain, leading to the enhancement of interfacial bonding and crystallization of copolyimide at interface and in filament. Therefore, the printed copolyimide specimens exhibited high heat resistance, high mechanical property and excellent interfacial bonding performance. The tensile strength of specimens printed in XY plane with 0° infill direction (XY-0), XY plane with 90° infill direction (XY-90) and XZ plane with 90° infill direction (XZ-90) were 110 MPa, 96 MPa and 57 MPa, respectively. The tensile strength of XY-0 printed specimen at 200 °C was 186 % higher than that of XY-0 printed amorphous polyimide specimen, reaching 40 MPa. This study expanded the kinds of polymeric materials suitable for fused deposition modeling, and provided the possibility of printing high performance engineering parts.

Investigation of the effect of the degree of hollowness and internal cavity structure on the mechanical properties of 3D-printed parts

Despite the wide growth of additive manufacturing, it is still very expensive to mass produce 3D-printed parts. The costs can be minimized if the quantity of material required to produce a part can be substantially reduced by introducing hollow cavities into the structure, without compromising its properties. This study investigates the effect of the degree of hollowness and different internal cavity structures on the mechanical properties of 3D-printed materials. Test specimens were prepared with four polymeric materials (i.e., acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), carbon fiber-reinforced (CFR) ABS, and CFR PLA) using the fused deposition modeling 3D printing technique. Internal hollow cavities were introduced to the specimens during printing and the specimens were prepared with three different cavity structures (i.e., hexagonal honeycomb, circular drills, and squares), and the degree of hollowness was varied from 0% to 30% in 10% increments. Tensile and flexural properties of the 3D-printed specimens were evaluated and analyzed. The mechanical properties of all specimens were found to decrease with increasing hollowness levels, regardless of the type of material or the internal cavity structure. The hexagonal honeycomb structure showed the best tensile properties out of the three internal cavity structures, while the flexural properties were not significantly affected by the internal cavity structure. The material type had a significant impact on the mechanical properties with PLA exhibiting better tensile and flexural properties than ABS, while their carbon fire reinforced counterparts showed enhanced mechanical properties than pure ABS and PLA.

Colombian Sustainability Perspective on Fused Deposition Modeling Technology: Opportunity to Develop Recycled and Biobased 3D Printing Filaments.

In the context of the preservation of natural resources, researchers show a growing interest in developing eco-friendly materials based on recycled polymers and natural fiber biocomposites to minimize plastic and agroindustrial waste pollution. The development of new materials must be integrated within the circular economy concepts to guarantee sustainable production. In parallel, fused deposition modeling, an additive manufacturing technology, provides the opportunity to use these new materials in an efficient and sustainable manner. This review presents the context of plastics and agro-industrial fiber pollution, followed by the opportunity to give them added value by applying circular economy concepts and implementing these residues to develop new materials for the manufacture of fused deposition modeling 3D printing technique feedstock. Colombian perspective is highlighted since 3D printing technology is growing there, and Colombian biodiversity represents a high reservoir of materials. Also, recycling in Colombia promotes compliance with the 2030 Agenda and the Sustainable Development Goals.

3D printed flexible wearable sensors based on triply periodic minimal surface structures for biomonitoring applications

Soft piezoresistive wearable conductors have led to a paradigm shift in the monitoring of human bodily motions. Cellular additively manufactured conductors are promising piezoresistive components as they offer mechanical tunability and provide controllable percolation pathways. In the present study, we engineer high surface-area cellular structures with the triply periodic minimal surface (TPMS)-based architectures to tailor their piezoresistive response for use in wearable devices. A simple and economical fabrication process is proposed, wherein a fused deposition modeling 3D printing technique is utilized to fabricate flexible thermoplastic polyurethane (TPU) cellular structures. Interconnectivity of TPMS designs enables the coating of a continuous graphene layer over the TPU internal surfaces via a facile dip-coating process. The effects of pore shape on piezoresistivity are studied in four different TPMS structures (i.e. Primitive, Diamond, Gyroid, and I-WP). Mechanical properties of sensors are evaluated through experimental procedures and computation methods using finite element analysis of the Mooney–Rivlin hyperelastic model. The piezoresistive performance of sensors exhibits durability under cyclic compression loading. Finally, we conclude that the Primitive structure offers suitable piezoresistive characteristics for sensing of walking, whereas the Diamond structure presents favorable results for respiration monitoring.

3D Printed Larynx as a Novel Simulation Tool for Window Elaboration in Medialization Laryngoplasty

ObjectiveSurgical simulation training in residents has declined due to the limited exposure to cadaveric specimens. Three-dimensional (3D)-printing technology is rapidly taking an important role in different medical areas, especially in surgical specialties. It provides an alternative for resident simulation practices and for developing surgical skills before exposure to real settings. The elaboration of the thyroid window in the medialization laryngoplasty procedure requires high technical precision and experience for better outcomes. MethodsThe computer-based 3D reconstruction model was created using computed tomograph scan images from a standard larynx. The final model was created using a deposition modeling 3D printing technique with polylactic acid filament. The model was tested for surgical simulation practice in three otolaryngology residency programs in Bogotá, Colombia. ResultsThe model had similar anatomic detail and it was considered very useful, safe, and relevant for surgical simulation. Conclusions3D printed models are a cost-effective alternative for resident training.

Flexible 3D Printed Conductive Metamaterial Units for Electromagnetic Applications in Microwaves.

In this work we present a method for fabricating three dimensional, ultralight and flexible millimeter metamaterial units using a commercial household 3D printer. The method is low-cost, fast, eco-friendly and accessible. In particular, we use the Fused Deposition Modeling 3D printing technique and we fabricate flexible conductive Spilt Ring Resonators (SRRs) in a free-standing form. We characterized the samples experimentally through measurements of their spectral transmission, using standard rectangular microwave waveguides. Our findings show that the resonators produce well defined resonant electromagnetic features that depend on the structural details and the infiltrating dielectric materials, indicating that the thin, flexible and light 3D printed structures may be used as electromagnetic microwave components and electromagnetic fabrics for coating a variety of devices and infrastructure units, while adapting to different shapes and sizes.

Additive manufacturing of resonant fluidic sensors based on photonic bandgap waveguides for terahertz applications.

A hollow-core Bragg waveguide-based resonant fluidic sensor operating in the terahertz frequency band is studied. A fused deposition modeling 3D printing technique with a Polylactic Acid filament is employed to fabricate the sensor where the liquid analyte is flowing in the microfluidic channel integrated into the waveguide cladding. The fluidic channel supports a resonant defect state which is probed spectrally using the core-guided mode of the Bragg waveguide. Continuous-wave terahertz spectroscopy is used to characterize the fluidic sensor. The measured signal amplitude shows a dip in the transmission spectrum, while the measured phase shows a sharp change in the vicinity of the anticrossing frequency whose spectral position depends strongly on the real part of the analyte refractive index. The sensor spectral response is further optimized by tailoring the waveguide length and position of the defect layer. Consistent with the results of numerical modeling, the measured sensor sensitivity is ~110 GHz/RIU, while the sensor resolution ~0.0045 RIU is limited by the parasitic standing waves in the spectrometer cavity. We believe that the proposed fluidic sensor opens new opportunities in applied chemical and biological sensing as it offers a non-contact measurement technique for monitoring refractive index changes in flowing liquids.

3D-Printed Pediatric Temporal Bone Models for Surgical Training: A Patient-Specific and Low-Cost Alternative

Aim: To determine the usefulness of low-cost 3D-printed pediatric temporal bone models and to define if they could be used as a tool for large-scale surgical training based on their affordability. Materials & methods: Prototypes of a pediatric temporal bone were printed using fused deposition modeling 3D printing technique. The prototypes were drilled. The surgical simulation experience was registered by means of a Likert scale questionnaire. Results: The prototypes adequately simulated a cadaveric temporal bone. The costs associated with production were low compared with other commercial models making it a cost-effective alternative for a temporal bone laboratory. Conclusion: Printed temporal bones created by means of fused deposition modeling are useful for surgical simulation and training in otolaryngology, and it is possible to achieve detailed low-cost models.

Improved thermal conductivity of thermoplastic polyurethane via aligned boron nitride platelets assisted by 3D printing

Thermal management is of importance to microelectronics. Owning both excellent thermal conduction and electrical insulation, hexagonal boron nitride (hBN) platelets are widely used in polymer matrices. While the thermal properties rely on the orientation of hBN platelets in polymer matrices significantly. Herein, we report that high thermal conductive hBN filled thermoplastic polyurethane (TPU) composites can be achieved by a fused deposition modeling 3D printing technique. The hBN platelets show excellent alignment along printing direction in TPU matrix due to the shear-inducing effect of printing. The sample along printing direction at filler loading of 25.9 vol% (40 wt%) exhibits the thermal conductivity up to 2.56 Wm−1 K−1 at 100 °C along printing direction, i.e. 10- and 2.8-time enhancement, compared to those of neat TPU and hBN/TPU sample tested along thickness direction. The surface temperature distribution of samples with various heating durations is also presented. The effects of some key parameters, i.e. nozzle diameter, printing speed as well as filler loading, on the alignment level of hBN are also investigated. Finally, the alignment level of the platelets is predicted by effective medium approximation, which is consistent with that measured by small angle X-ray scattering.

3D Complex Structures Through Fused Deposition Modeling as a Rapid Prototyping Technology Designed for Replacing Anatomic Parts of Human Body

Abstract The paper aims to demonstrate the capability of FDM – Fused Deposition Modeling 3D printing technique to build complex structures designed for replacing anatomic parts of human body. It proposes to push the limits of FDM machine in order to achieve both structural integrity, mechanical properties and complexity of the 3D print part. Main applicability focus on bioengineering - developing new, lightweight implants but also can easily extended to airspace/automotive industry.

Fabrication and characterization of 3D printed BaTiO3/PVDF nanocomposites

This paper presents a fabrication process to enhance homogeneous dispersion of BaTiO3 nanoparticles in polyvinylidene fluoride matrix nanocomposites using fused deposition modeling (FDM) 3D printing technique. The nanocomposites integrate the functional property (piezoelectric, pyroelectric, and dielectric) of BaTiO3 with the flexibility and lightweight of polyvinylidene fluoride. Traditionally, the simple yet effective way to fabricate the nanocomposites includes solvent-casting, spin-coating, and hot-embossing. However, these methods have disadvantages such as heterogeneous dispersion of BaTiO3 nanoparticles in polyvinylidene fluoride matrix due to the higher density of BaTiO3 compared with polyvinylidene fluoride and agglomeration during fabrication process. This heterogeneous dispersion could weaken functional and mechanical properties. Herein, fused deposition modeling 3D printing technique was utilized for homogeneous dispersion to alleviate the agglomeration of BaTiO3 in polyvinylidene fluoride through two processes: filament extrusion and 3D printing. In addition, thermal poling was applied to further enhance piezoelectric response of the BaTiO3/polyvinylidene fluoride nanocomposites. It is found that 3D printed BaTiO3/polyvinylidene fluoride nanocomposites exhibit three times higher piezoelectric response than solvent-casted nanocomposites.

Simplified fabrication of integrated microfluidic devices using fused deposition modeling 3D printing

Microfluidic devices based on polydimethylsiloxane shown a plethora of experimental possibilities due to good transparency, flexibility and ability to adhere reversibly and irreversibly to distinct materials. Though PDMS is a milestone in microfluidic developments, its cost and handling directed the field to search for new options. 3D printing technology nowadays starts a revolution offering materials and possibilities that can contribute positively to current methodologies. Here we explored the fused deposition modeling 3D printing technique to obtain integrated, transparent and sealed microchannels made with polylactic acid, a cheap alternative material to set up microfluidic systems. Using a home-made 3D printer, devices could be assembled in a simplified process, enabling the integration of different materials such as paper, glass, wire and polymers within the microchannel. To demonstrate the efficacy of this approach, a 3D-printed electronic tongue sensor was built, enabling the distinction of basic tastes below the human threshold.