Printing Precision Research Articles

The Influence of Pigments on Ultrasonic Welding Behaviour of 3D Printed Components Using the Low Force Stereolithography Technology

The purpose of this paper is to study the strength characteristics of V4 resin components that are welded using ultrasonics. These components are created using the Low Force Stereolithography (LFS) technology, which reduces the printing forces for achieving the best possible finish. Welding components are 3D printed with a Form 3+ 3D printer, known for its high printing precision, employing a powerful laser and a spatial filter. Key characteristics of the ultrasonically welded components can be extracted, analysed, and summarized to provide guidance on the optimal resin selection.

A comparative quantitative assessment of 3D-printed PEKK and PEEK thin meshes in customized alveolar bone augmentation

ObjectiveCustomized nonabsorbable membranes are widely used in severe alveolar bone defects and provide sufficient and precise regenerated bone tissue for subsequent dental implant placement. Although 3D-printed polyetheretherketone (PEEK) meshes have confirmed successful use in clinical cases, the performance of a PEEK mesh is not satisfactory. Compared with PEEK, polyetherketoneketone (PEKK) has better mechanical and processing properties. However, whether PEKK is suitable for making customized membranes remains unclear. The objectives of this study were (1) to evaluate the printing precision, surface characteristics, mechanical characteristics and biocompatibility of the PEKK mesh and (2) to compare the properties of the PEKK and PEEK meshes.Materials and methodsBoth PEKK and PEEK meshes were designed and manufactured via additive manufacturing technology combined with computer-aided design (CAD). The printing precision was evaluated with a high-resolution extraoral scanner. The surface characteristics were evaluated with a contact angle system and three-dimensional optical microscopy. The mechanical characteristics were evaluated via three-point bending tests and tensile tests. The biocompatibility was evaluated with a CCK-8 assay, live/dead viability assay and qRT-PCT.ResultsCompared with the PEEK mesh, the PEKK mesh exhibited better control in terms of the thickness and aperture area. Both the PEKK mesh and the PEEK mesh had a hydrophobic surface, but the PEKK mesh had a smoother surface. Compared with the PEEK mesh, the PEKK mesh has better compression and tensile properties. Both the PEKK mesh and the PEEK mesh had good biocompatibility. The proliferation of cells on the PEKK mesh was slightly lower than that on the PEEK mesh.ConclusionsCompared with PEEK mesh, PEKK mesh has greater printing accuracy, smoother surfaces, better mechanical properties and similar biocompatibility and is expected to be used in the production of customized barrier membranes for the augmentation of severe bone defects. To ensure the stability of the mesh for clinical application, it is best to control the aperture diameter of the PEKK mesh to less than 2 mm with a thickness of 0.2 μm.

Modeling the interaction between powder particles and laser heat sources

This study investigates the spheroidization of titanium Ti-6Al-4V powder particles using numerical models developed in Abaqus and OpenFOAM. Spherical particles are crucial in powder-based additive manufacturing due to their superior flowability, packing density, and mechanical properties, enhancing printing precision and the quality of final products. While conventional techniques such as gas atomization and plasma spheroidization have been extensively researched, the potential of laser spheroidization remains underexplored. To address this gap, detailed numerical analyses of laser spheroidization were conducted, modeling heat transfer from the laser to powder particles using a transient uncoupled heat transfer method with latent heat considerations, while particle deformation was simulated with a phase-fraction-based interface-capturing approach integrated with Navier-Stokes equations. The results, validated against analytical models, indicate that particles within the 20–80 μm range experience optimal spheroidization within a 0.005-second residence time under laser heating, with particles smaller than 30 μm reaching evaporation temperatures of 5,000°C, while larger particles reshape without evaporating under a typical heat flux of 94 MW/m2 (1.8 kW laser power). This study demonstrates that laser spheroidization of Ti-6Al-4V powder can potentially increase powder yield by 10%, offering higher power density and shorter melting times compared to plasma spheroidization, thus presenting a more efficient alternative for achieving spherical particles of specific sizes.

Contactless printing of food micro-particles controlled by ultrasound

Traditional food 3D printing technology, which primarily relies on mechanical control, often faces challenges such as low resolution, stringent material requirements, limited flexibility, and cumbersome equipment. To overcome these limitations, we developed an innovative food 3D printing method utilizing ultrasonic phased arrays and subsequently designed a contactless printing device employing this advanced technology. The device effectively manipulates the phase and amplitude of the ultrasonic phased array to focus the sound field on a specific location. We have successfully demonstrated preliminary control over the suspension of small food particles, including popcorn, chocolate, honey, and marshmallows, using this apparatus. Following this, popcorn particles were selected for detailed practical printing and further analysis. Additionally, we established a software platform, Ultr_printing, based on Ultraino, for intelligent simulation and control of the printing process. Leveraging FPGA and Arduino controllers, this setup facilitates rapid signal transmission from personal computers to sensors, ensuring quick and adaptable movement of suspended particles. Experimental results confirm that the device consistently controls the food particles, irrespective of their motion state. Notably, it achieves a printing precision of 0.16 mm when handling popcorn particles measuring 1.5 mm in diameter. The process, entirely contactless and free from contamination, preserves the original flavor of the food particles. This technology is particularly effective for high-precision printing of micro-scale shapes and offers considerable benefits in assembly and precision manufacturing.

Enhancing precision in 3D printing for highly functional printing with high-speed vision

3D printing has revolutionized product design and manufacturing across various industries by enabling the creation of complex geometries with minimal waste. Despite its advancements, 3D printing still faces significant challenges, including spatial constraints and process control limitations. This paper introduces novel approaches to improve the functionality and precision of material extrusion 3D printers for the fused deposition modeling method, particularly for additional printing tasks such as printing on existing objects or continuing a print on a relocated object without prior knowledge of its position or even the environment is changed. We introduce a compensation system integrating a high-speed vision system for robot arms to address these challenges. Our system employs a three-step pose estimation process—fast point feature histograms (FPFH)-based, corner-based, and sub-pixel edge-based methods—to ensure high accuracy in restoring the position of printed pieces for additional printing tasks on a given object. Experimental results demonstrate substantial improvements in printing precision, with the system achieving sub-millimeter and sub-pixel accuracy. These advancements not only eliminate work area constraints but also enhance the adaptability and reliability of 3D printing processes.

Impact of hydrocolloids on 3D meat analog printing and cooking

This study investigated the effects of hydrocolloid addition on three-dimensional (3D) printing and cooking of plant ingredients-based meat analog (MA). The MA inks were formulated with soy protein isolate, wheat gluten, canola oil, water, and hydrocolloids (xanthan gum, pectin, hydroxypropyl methylcellulose, guar gum, locust bean gum) at a ratio of 22:12:15:88:2. Formulated inks were used to create a specific 3D cylindrical model geometry and the printed structure were subjected to air frying (AF:180°C, 15 min) and infrared heating (IR:180°C, 15 min). Results showed that the MA ink’s viscosity (3871–5482 Pa. s), 3D printing rate (0.34–0.39 g.sec−1), printing error (2.51–10.37 %), and printing precision (81.97–97.27 %) were significantly (p<0.05) impacted by the incorporation of hydrocolloids. The dimensional stability (63.17–98.58 %), and cooking loss (6.70–17.41 %) were greatly impacted by both the hydrocolloids and post-printing cooking methods. Moisture (1.71 db) and fat (0.28 db) content of uncooked 3D printed MA were identical, whereas, differences in color attributes (L value:80.21–98.88, a value:0.01–0.13, b value:0.11–2.11) among the studied hydrocolloid added samples were observed. Moisture, fat, and color traits of 3D printed meat-analogs were significantly (p<0.05) impacted by post-printing cooking methods (AF, IR). During post-printing cooking, the loss of mass (moisture, fat) and changes in color tones were associated with the types of hydrocolloids incorporated in formulating the 3D printing ink. Surfaces and internal structure, mass loss, chemical profile, and glass-transition-temperature of 3D printed meat-analogs were significantly (p<0.05) impacted by both the type of incorporated hydrocolloids and post-printing cooking methods.

Dimension compensation of printed master molds by a desktop LCD 3D printer for high-precision microfluidic applications.

Recent advances in low-cost liquid crystal display (LCD) 3D printing have popularized its use in creating microfluidic master molds and complete devices. However, the quality and precision of these fabrications often fall short of the rigorous standards required for advanced microfluidic applications. This study introduces a novel approach to enhance the dimensional accuracy of microchannels produced using a desktop LCD 3D printer. We propose a method for dimension compensation, optimize the printing parameters, and provide a straightforward post-treatment technique to ensure high-quality curing of polydimethylsiloxane (PDMS) in master molds made from photosensitive resin. Our investigation assesses the precision of 3D printing across three different scales of square cross-section microchannels by measuring their widths and heights, leading to the determination of optimal printing parameters that minimize dimensional errors. The dimensional errors are further reduced by introducing a series of dimension compensation factors, which correct the nominal dimensions of the microchannels by using the compensation factors in 3D printing. The dimensional accuracy is significantly improved after compensation even in fabricating complex microchannels of triangular cross-sections. Finally, a spiral channel of trapezoidal-like cross-section with tilted edges is fabricated for microfluidic application, and highly efficient particle separation is realized in the channel. The proposed method provides new insights for utilizing desktop LCD 3D printers to achieve high-accuracy microstructures necessary for advanced microfluidic applications.

Advances in 3D bioprinting for environmental remediation and hazardous materials treatment.

The high-throughput method based on the micron-level structure that 3D bioprinting technology offers for various environmental microbiological engineering applications is made possible by its several printing paths and precision programming control. This versatility makes it an on-demand manufacturing technology. A novel 3D manufacturing technique called 3D bioprinting may be used to precisely uptake and disperse bacteria to create microbial active substances with a variety of intricate functionalities for environmental applications. The technological challenges that the current 3D bioprinting technology must face include the mechanical properties of materials, the creation of specific bioinks to adapt to different strains, and the exploration of 4D bioprinting for intelligent applications. Therefore, this analysis delves deeply into the core technological ideas of 3D bioprinting, bioink materials, and their environmental applications. It also offers recommendations about the challenges and opportunities associated with 3D bioprinting. Combined with the present advancements in microbe enhancement technology, 3D bioprinting will provide an enabling platform for multifunctional microorganisms and facilitate the management of in situ directional responses in the environmental domain. This review highlights the applications of 3D bioprinting in the environmental monitoring and bioremediation. 3D printing in solid waste management is also discussed in detail.

The influence of heating and cooling on the precision and microstructure of 3D printing results with PLA+ material

The influence of heating and cooling on the precision and microstructure of 3D printing results with PLA+ material

Selective Laser Melting: A Novel Method for Surface Roughness Analysis

The present study introduces a novel approach to analyse the surface roughness of metal parts made by 3D selective laser melting (SLM). This technology, known for its ability to efficiently produce functional prototypes and limited-run series, is particularly effective when surface conditions directly meet usage requir ements. Thus, the suitability of surfaces is a critical factor, emphasizing the importance of new methods for predicting their quality. Here fractal geometry and network theory are integrated to delve into the complexities of SLM-produced surfaces, while machine learning and pattern recognition concepts are employed to evaluate the surface roughness. Specifically, genetic programming, artificial neural networks, support vector machine, random forest, k-nearest neighbors are compared in terms of accuracy demonstrating that only the first method provided valid estimation due to the presence of very little training data. Experimental work with EOS Maraging Steel MS1 and an EOS M 290 3D printer validates the method’s practicality and effectiveness. Then, the research offers a fresh perspective in surface analysis and has significant implications for quality control in additive manufacturing, potentially enhancing the precision and efficiency of 3D metal printing.

Stereolithographic 3D Printing of Intrinsically Flame‐Retardant Shape‐Memory Polymers

AbstractThis study presents a novel approach to fabricate 3D‐printed phosphorous‐based acrylate monomers using stereolithographic 3D printing technology, aiming to create demonstrators with exceptional shape‐memory characteristics and robust flame retardant properties. The synthesized materials combine the advantages of 3D printing precision with the intrinsic flame retardancy of phosphorous‐based monomers, offering a versatile solution for applications requiring both shape memory functionality and fire resistance. The limiting oxygen index (LOI) value of the intrinsically flame‐retardant shape‐memory polymer (IFR‐SMP) can reach 34%, and the vertical combustion rating after UL 94 can obtain V‐0. The mechanism of the IFR‐SMP flame retardant mainly includes terminating a free‐radical chain reaction and gas phase dilution, which indicates that the gas‐phase mechanism plays an important role in the flame retardancy. This work advances the frontiers of 3D printing technology by demonstrating the synergistic potential of shape memory and flame retardancy within a single material system, providing a pathway toward the development of innovative and resilient materials for the future.

Interphase-Controlled Inkjet Printing of MicroInlaid OLEDs: Effects of Solvent- and Solute-Polymer Interactions.

Inkjet printing, a highly promising technique for the cost-effective fabrication of large-scale organic light-emitting devices (OLEDs), typically necessitates the intricate alignment of precisely patterned insulating layers. Recently, we introduced a unique single-step inkjet printing process that produces well-patterned microinlaid spots of functional compounds through insulating polymer layers. This approach exploits lateral phase separation between the solute of functional compounds and the polymer, allowing the simultaneous spatial etching of the polymer and the infilling of the solute using a single inkjet-printed sessile droplet. Here, we demonstrate that the interaction between the solvent and polymer, as well as the solute and polymer, critically determines the precision and efficiency of printing. This is particularly evident when using either the insulating poly(vinylpyridine) isomer of poly(4-vinylpyridine) (P4VP) or poly(2-vinylpyridine) (P2VP) with chloroform as a solvent, which allows for a detailed examination of these interactions based on certain solubility parameters. Micro-Raman spectroscopy reveals that the self-organizing capability of the microinlaid spots with P4VP is superior to that with P2VP. This is due to the fact that P2VP shows higher affinity to the solvent and causes imperfect phase separation as compared to P4VP. As a result, a performance evaluation demonstrates enhanced device performance for inkjet-printed green micro-OLEDs with P4VP, exhibiting a higher external quantum efficiency of 3.3% compared to that of 2.3% achieved with P2VP. These findings elucidate the important roles of solvent-polymer and solute-polymer interactions in the inkjet printing process, leading to interfacial control of inkjet printing technique for the cost-effective production of high-performance and high-resolution micro-OLEDs.

Additive Manufacturing: A Paradigm Shift in Revolutionizing Catalysis with 3D Printed Photocatalysts and Electrocatalysts Toward Environmental Sustainability.

Semiconductor-based materials utilized in photocatalysts and electrocatalysts present a sophisticated solution for efficient solar energy utilization and bias control, a field extensively explored for its potential in sustainable energy and environmental management. Recently, 3D printing has emerged as a transformative technology, offering rapid, cost-efficient, and highly customizable approaches to designing photocatalysts and electrocatalysts with precise structural control and tailored substrates. The adaptability and precision of printing facilitate seamless integration, loading, and blending of diverse photo(electro)catalytic materials during the printing process, significantly reducing material loss compared to traditional methods. Despite the evident advantages of 3D printing, a comprehensive compendium delineating its application in the realm of photocatalysis and electrocatalysis is conspicuously absent. This paper initiates by delving into the fundamental principles and mechanisms underpinning photocatalysts electrocatalysts and 3D printing. Subsequently, an exhaustive overview of the latest 3D printing techniques, underscoring their pivotal role in shaping the landscape of photocatalysts and electrocatalysts for energy and environmental applications. Furthermore, the paper examines various methodologies for seamlessly incorporating catalysts into 3D printed substrates, elucidating the consequential effects of catalyst deposition on catalytic properties. Finally, the paper thoroughly discusses the challenges that necessitate focused attention and resolution for future advancements in this domain.

Fabrication of 3D-Printed Scaffolds with Multiscale Porosity.

3D printing is a promising technique for producing bone implants, but there is still a need to adjust efficiency, facilitate production, and improve biocompatibility. Porous materials have a proven positive effect on the regeneration of bone tissue, but their production is associated with numerous limitations. In this work, we described a simple method of producing polymer or polymer-ceramic filaments for 3D-printing scaffolds by adding micrometer-scale porous structures on scaffold surfaces. Scaffolds included polycaprolactone (PCL) as the primary polymer, β-tricalcium phosphate (β-TCP) as the ceramic filler, and poly(ethylene glycol) (PEG) as a porogen. The pressurized filament extrusion gave flexible filaments composed of PCL, β-TCP, and PEG, which are ready to use in fused filament fabrication (FFF) 3D printers. Washing of 3D-printed scaffolds in ethanol solution removed PEG and revealed a microporous structure and ceramic particles on the scaffold's surfaces. Furthermore, 3D-printed materials exhibit good printing precision, no cytotoxic properties, and highly impact MG63 cell alignment. Although combining PCL, PEG, and β-TCP is quite popular, the presented method allows the production of porous scaffolds with a well-organized structure without advanced equipment, and the produced filaments can be used to 3D print scaffolds on a simple commercially available 3D printer.

A Novel Compliant Connection Mechanism with Thermal Distortion Self-Elimination Function.

As a novel technology for fabricating large-screen OLED devices, OLED inkjet printing places extreme demands on the positioning accuracy of inkjet printing platforms. However, thermal deformation of the connection mechanism often reduces the printing precision of OLED printing equipment, significantly impacting overall print quality. This study introduces a compliant connection mechanism that achieves precise positioning of the inkjet printing platform and can self-eliminate thermal distortion. The design of the mechanism's core component is based on the Freedom and Constraint Topology (FACT) principle. This component is constructed from three distinct compliant sections arranged in series, collectively providing three degrees of freedom. Furthermore, the resistance to deformation caused by gravity and other external forces was evaluated by analyzing both vertical and horizontal stiffness. To validate the mechanism's thermal distortion elimination and gravity resistance capabilities, finite element analysis (FEA) was carried out. The results demonstrate that the mechanism effectively reduces the maximum deformation of the platform by approximately 46% and the average deformation across the entire platform by approximately 59%. These findings confirm that the mechanism has potential in high-precision positioning tasks that need to mitigate thermal distortion.

Optimization of the extrusion rate for different layer thicknesses to achieve controlled mechanical properties in MEX 3D printing of low-alloy steel

Composite extrusion modeling is an advanced material extrusion additive manufacturing process that requires fine-tuning of printing parameters for printing injection molding feedstocks. In order to achieve comparable high-quality parts at different layer thicknesses, the parameters must be optimized for the respective layer thicknesses. In this work, the printing parameters for AISI 8740 low-alloy steel injection molding material are optimized for four different layer thicknesses. The extrusion multiplier values for each layer thickness are tuned, allowing fine adjustment of the printer's screw rotation speed at every layer thickness, resulting in all final parts' maximum densities (≥ 98 %) with high accuracies. Scanning electron microscope images, surface roughness measurements, and printing precision tests proved the good and comparable high-quality of all optimized printed parts. Young's modulus, tensile and yield strengths also raised by ∼24 %, ∼16 % and ∼15 %, respectively, compared to the non-optimized printed sintered part. The achieved tensile strength range of (∼888–947) MPa and yield strength range of (∼574–586) MPa of all optimized printed sintered parts were also higher than those provided by the feedstock manufacturer. This promising approach significantly reduces printing time and manufacturing costs without compromising the printed final parts' quality and mechanical properties. The adjusting screw rotation speed methodology allows broader applicability across diverse material extrusion processes.

Mechanistic study on the role of 3D-Printed biomimetic coral bone scaffolds in bone defect repair

With the continuous innovation and development of 3D printing technology, 3D-printed biomimetic coral bone scaffolds have demonstrated significant potential in the field of bone defect repair. This paper aims to explore in-depth the mechanistic study of 3D-printed biomimetic coral bone scaffolds in bone defect repair, by systematically reviewing relevant literature and analyzing their potential mechanisms in promoting bone growth and improving the success rate of bone defect repair. Firstly, this paper introduces the fabrication process and material characteristics of 3D-printed biomimetic coral bone scaffolds. Secondly, the paper discusses the mechanisms of 3D-printed biomimetic coral bone scaffolds in terms of biocompatibility, biomechanical performance, as well as their roles in vascularization and bone formation. Finally, the paper outlines future research directions for 3D-printed biomimetic coral bone scaffolds, including further optimization of material properties, improvement of printing precision, and expansion of clinical applications.

Synergistic improvement of mechanical and piezoelectric properties of the flexible piezoelectric ceramic composite and its high-precision preparation

Flexible piezoelectric ceramic composites (FPCCs) hold promising applications in fields such as flexible sensing and energy harvesting. However, the previous methods are difficult to achieve high-precision preparation of the FPCCs with complex structures, as well as the synergistic enhancement of piezoelectric performance and flexibility. In this study, by configuring a flexible resin matrix and employing a surface functionalization treatment on the piezoelectric ceramic particles, the flexibility and piezoelectric performance of the FPCCs are synergistically improved. Moreover, the addition of a light absorber, TiO2, significantly improves the 3D printing precision. The mechanical properties, piezoelectric performance, and printing precision of the FPCCs are analyzed. It is found that the printing error is less than 2 μm, the tensile fracture strength is 4.07 MPa, the elongation at break is 350 %, and the piezoelectric constant d33 can reach 7.7 pC/N. In addition, the cyclic loading tests show that FPCCs with high-precision 3D complex microstructure have good recovery performance. This study not only enriches the formulation of FPCCs slurry for 3D printing, but also provides a research foundation for the multifunctional applications.

Radio frequency air cold plasma pretreatment to enhance 3D printing performance of tapioca starch by altering its rheological behavior and water migration

This work investigated the effect of radio frequency air cold plasma (RFACP) pretreatment in enhancing 3D printing performance of tapioca starch. The results of 3D printing showed that the cold plasma (CP) treatment enhanced printing precision from 75.88% to 89.16% in starch. On the one hand, it could appropriately weaken the fluidity of starch ink to reduce the printing line width. On the other hand, it could enhance the self-supporting ability of starch ink and alleviate the sagging and collapse of 3D patterns. The results of rheological behavior further demonstrated that CP-treated starch exhibited greater gel structure characterized by the increased viscoelasticity, rigidity, and structural recovery capacity. Additionally, CP treatment facilitated the migration of free water into immobilized states within the starch ink and shortened relaxation times, indicating an enhanced water-binding ability of the CP-treated starch. Correlation analysis showed that rheological properties, firmness and water distribution of starch ink were significantly linked with the printability. The improvement of starch 3D printing performance after CP treatment may be attributed to the higher amylose content and more hydrophilic groups (especially carboxyl) generated by CP depolymerization and oxidation effects, which could lead to a denser network structure with greater mechanical strength of starch gel. Overall, this study not only reveals the mechanism that CP treatment enhances 3D printing performance of starch, but also provides a green and effective way to improve the 3D printing performance of starch.

3D printed emulsion based on arginine-myofibrillar protein

The feasibility of preparing high internal phase Pickering emulsions (HIPPEs) from arginine (Arg) and tilapia myofibrillar protein (MP) complex particles for 3D printing was investigated. The characterization of Arg-MP solutions showed that the Arg-MP complexes had excellent emulsification potential. HIPPE stabilized by Arg-MP had a strong self-supporting and stable gel structure. Therefore, HIPPE stabilized by Arg-MP showed excellent stability. Furthermore, the viscoelasticity and thixotropic recovery of the Arg-MP-stabilized HIPPEs increased with increasing Arg concentrations. This made them suitable for 3D printing. Notably, the Arg-MP stabilized HIPPEs exhibited the best printing precision shape, resolution, and clear contours in 3D printing at an Arg concentration of 0.5 wt%. Our results provide a valuable source of food-grade materials for 3D printing inks and demonstrate a promising strategy for deep processing of tilapia myofibrillar protein.