Printing Speed Research Articles

Rheological Changes in Bio-Based Filaments Induced by Extrusion-Based 3D Printing Process.

In this work, the authors investigated the impact of extrusion-based printing process on the structural characteristics of bio-based resins through rheological measurements. Two commercially available filaments made from unfilled and wood-filled polylactide (PLA) polymers were considered. Three-dimensional specimens were prepared by printing these filaments under various operating conditions, i.e., changing the extruder temperature and printing rate, and examined using time sweep tests. Specific cycle rheological testing was conducted on pelletized filaments to simulate temperature changes in the printing process. The rheological characteristics of unprocessed materials, in terms of storage (G') and loss (G″) moduli, were found to be slightly affected by temperature changes. For a pure polymer, the G' slope at a low frequency decreased over time, showing that the polymer chains evolved from a higher to a lower molecular weight. For wood-filled materials, the G' slope rose over the testing time, emphasizing the formation of a percolated network of structured filler within the matrix. On the other side, the rheological parameters of both materials were strongly impacted by the printing extrusion and the related conditions. At lower nozzle temperatures (200 °C), by decreasing the printing speed, the G' and G″ curves became increasingly different with respect to unprocessed resin; whereas at higher nozzle temperatures (220 °C), the influence of the printing speed was insignificant, and all curves (albeit distant from those of unprocessed matrix) mainly overlapped. Considerations on degradation kinetics of both materials during the printing process were also provided by fitting experimental data of complex viscosity with linear correlation over time.

Conductive collagen/polypyrrole-b-polycaprolactone hydrogel for bioprinting of neural tissue constructs.

Bioprinting is increasingly being used for fabrication of engineered tissues for regenerative medicine, drug testing, and other biomedical applications. The success of this technology lies with the development of suitable bioinks and hydrogels that are specific to the intended tissue application. For applications such as neural tissue engineering, conductivity plays an important role in determining the neural differentiation and neural tissue regeneration. Although several conductive hydrogels based on metal nanoparticles (NPs) such as gold and silver, carbon-based materials such as graphene and carbon nanotubes and conducting polymers such as polypyrrole (PPy) and polyaniline were used, they possess several disadvantages. The long-term cytotoxicity of metal nanoparticles (NPs) and carbon-based materials restricts their use in regenerative medicine. The conductive polymers, on the other hand, are non-biodegradable and possess weak mechanical properties limiting their printability into three-dimensional constructs. The aim of this study is to develop a biodegradable, conductive, and printable hydrogel based on collagen and a block copolymer of PPy and polycaprolactone (PCL) (PPy-block-poly(caprolactone) [PPy-b-PCL]) for bioprinting of neural tissue constructs. The printability, including the influence of the printing speed and material flow rate on the printed fiber width; rheological properties; and cytotoxicity of these hydrogels were studied. The results prove that the collagen/PPy-b-PCL hydrogels possessed better printability and biocompatibility. Thus, the collagen/PPy-b-PCL hydrogels reported this study has the potential to be used in the bioprinting of neural tissue constructs for the repair of damaged neural tissues and drug testing or precision medicine applications.

Predictive modeling and optimization of Rockwell hardness of additively manufactured PEEK using RSM, ANFIS and RNN integrated with PSO

The purpose of this research is to investigate the correlation between statistical and machine learning techniques and additive manufacturing, with a specific focus on predicting the Rockwell hardness of FDM-printed polyether ether ketone (PEEK) components. These components have a significant impact on various industries, such as aerospace, biomedical, and automobile. The study analyzes the hardness by conducting experimental analysis of four process parameters, including infill density, layer height, printing speed, and infill pattern. The research utilizes Response Surface Methodology (RSM), Adaptive Neuro-Fuzzy Inference System (ANFIS), and Recurrent Neural Network (RNN) to accurately predict the Rockwell hardness of the printed parts, with an average deviation of less than 5% from the experimental value. The study also investigates how hardness varies with FDM process parameters using contour and surface plots. Furthermore, the study utilizes RNN integrated with the Particle Swarm Optimization (PSO) algorithm to optimize Rockwell hardness. This approach achieved a peak Rockwell hardness value of 66.89 RHN under conditions of 80% infill density, 0.1mm layer height, 25 mm sec−1 printing speed, and an octet infill pattern. Microstructural examinations and test results corroborate the findings derived from parametric analysis and optimization efforts.

3D-Printed Meat Paste Using Minimal Additive: Assessment of Rheological and Printing Behavior with Post-Processing Stability

Printing foods in the desired shape with minimal additives and their stability after printing are the most important points for 3D food technology. In this study, the effects of water (5%, 10%, 15%, and 20%) and salt (0.5%, 1%, 1.5%, and 2%) on the printability of meat paste were evaluated to achieve improved textural and rheological properties. The printing parameters were examined at every stage, starting from the line thickness of the printed product, until the final 3D printed product was obtained. Accordingly, meat printability determined using different ingredient flow speed (3, 3.5, 4, 4.5, and 5), fill factor (1.2%, 1.3%, 1.4%, 1.5%, and 1.6%) and distance between layers (1.2, 1.4, and 1.6 mm). Salt addition increased the firmness and consistency of the samples, while the viscosity, storage modulus, and loss modulus decreased with the addition of water. Considering the line thickness and outer length, the most appropriate shape was obtained with 10% water and 1.5% salt. The optimal ingredient flow speed, fill factor, and distance between layers at a constant printing speed (2500 mm/min) were 3, 1.2%, and 1.4 mm, respectively. Four-layer-infilled 3D-printed samples maintained their initial shape after cooking, regardless of the cooking method. However, only baked products maintained their initial shapes among full-infilled samples. Although water and salt have different functions in meat, the use of the appropriate ratio is necessary for 3D-printed meat-based products to provide printability and post-production stability. To sum up optimum parameters and road map for printing meat and meat products including leftover meats and low-value by-products were revealed.

Investigation on mechanical properties of bronze infill PLA composite fabricated by fused deposition modelling

This study is on the mechanical properties of bronze infill poly lactic acid composites fabricated by fused deposition modelling. By changing the nozzle temperature, printing speed, layer thickness and infill density the mechanical properties of the composites were studied. Tensile, flexural and impact strength tests were conducted on the composite specimen. Mathematical models were developed using response surface methodology and the significance of the models was tested using analysis of variance. Increase in infill density and nozzle temperature increased the strengths of the composites. Increase in layer thickness and printing speed decreased the strengths of the composite specimen. Tensile strength is primarily influenced by infill density (38.82%), flexural strength is primarily influenced by Nozzle Temperature contributes (44.02%) while Infill density (58.12%) plays the major role in contributing the impact strength followed by other parameters. The highest tensile strength, flexural strength, impact strength values obtained in this study are 19.3 (N/mm2), 36.08 (N/mm2) and 0.26 (kJ/m2) respectively. The mechanism of the fractured specimen was investigated using scanning electron microscopy. Fracture mechanisms such as cracks, infill gaps, voids, interface, delamination, hillocks, particle pull out, delamination had an effect on the fracture of composite specimens.

Enhancing the functionality of sugar palm (Arenga Pinnata) fibre reinforced polylactic acid composite filament of fused deposition modelling through Taguchi method

Constructing functional components using Fused Deposition Modelling (FDM) is challenging due to various processing factors that influence the quality of the final product. The main reason for this is the many processing parameters involved, which have the ability to impact the quality of the produced components. The aim of this research is to use the Taguchi technique in attempt to improve the printing variables for attaining the best possible mechanical and physical qualities in the three-dimensional (3D) printed product made from sugar palm fibre reinforced polylactic acid (SPF/PLA). The layer thickness, infill density, and printing speed are characteristics that directly affect the mechanical qualities, surface roughness, and dimensional accuracy of FDM products. The research applied Taguchi’s L9 array, consisting of 9 experimental trials, with each trial including 5 duplicated specimens. Thus, a total of 45 specimens were generated by altering various processing settings. The most effective printing settings for FDM using SPF and PLA were found to be a layer thickness of 0.1 mm, infill density set to 100%, and a printing speed of 25 mm s−1. The microscopic images reveal a significant rise in the number of voids as the layer thickness is raised. Additionally, the printing speed has a substantial impact on the nead structure, making it more resilient. Overall, the results will provide a significant collection of data in the area of 3D printing, improving the utilization of indigenous plant fibres in additive manufacturing technology.

Evaluation of Material Extrusion Printed PEEK Mold Inserts for Usage in Ceramic Injection Molding

The rapid tooling of mold inserts for injection molding allows for very fast product development, as well as a highly customized design. For this, a combination of rapid prototyping methods with suitable polymer materials, like the high-performance thermoplastic polymer polyetheretherketone (PEEK), should be applied. As a drawback, a huge processing temperature beyond 400 °C is necessary for material extrusion (MEX)-based 3D printing; here, Fused Filament Fabrication (FFF) requires a more sophisticated printing parameter investigation. In this work, suitable MEX printing strategies, covering printing parameters like printing temperature and speed, for the realization of two different mold insert surface geometries were evaluated, and the resulting print quality was inspected. As a proof of concept, ceramic injection molding was used for replication. Under consideration of the two different test structures, the ceramic feedstock could be replicated successfully and to an acceptable quality without significant mold insert deterioration.

Evaluation of multi-walled carbon nanotubes alignment during 3D printing of poly(acrylonitrile-butadiene-styrene) nanocomposite filaments

Nanocomposites incorporated with one-dimensional electrical conductive materials such as carbon nanotubes have been used in many applications in various industries. In this research, the filaments made of poly (acrylonitrile-butadiene-styrene) (ABS) containing 1, 3, and 5 wt% multi-walled carbon nanotubes (MWCNT) were first prepared and then printed in three directions and two printing speeds. The rheological and electrical percolation thresholds were found to take place at 0.32 and 0.96 wt% MWCNT, respectively. Using the Casson plot, it was revealed that the yield stress of the nanocomposites containing 5 wt% MWCNT was 70 times higher than that of the pristine ABS. The results also indicated that the electrical resistance decreased from 17.4 to 6.8 Ω with the increase in printing speed from 4 to 20 mm/s, respectively. The alignment of the nanofillers was examined using X-ray diffraction method. It was found from the azimuth angle that the materials printed at higher printing speed had more orientation, with respect to the director, in comparison with that of printed at lower speed.

Optimization of Flexural Performance of PETG Samples Produced by Fused Filament Fabrication with Response Surface Method.

Additive manufacturing (AM), particularly fused filament fabrication (FFF), has gained significant attention for its design flexibility and cost-effectiveness. This study focuses on optimizing FFF parameters that employ response surface methodology (RSM) to enhance the flexural performance of polyethylene terephthalate glycol (PETG) parts. Three essential parameters-layer height, print speed, and nozzle temperature-were varied, and their effects on flexural strength, flexural modulus, flexural toughness for ultimate strength, flexural toughness at 5% strain, and strain at ultimate strength were evaluated. Based on a Box-Behnken design, the experiments revealed significant effects of these parameters on the mechanical responses. The analysis of variance (ANOVA) indicates that layer height predominantly affects flexural modulus and toughness, while nozzle temperature significantly impacts flexural strength. The RSM models exhibited high accuracy, with R2 values exceeding 99%. Optimal parameter combinations yield remarkable improvements: flexural strength reached 39.55 MPa, flexural modulus peaked at 1344.60 MPa, flexural toughness for ultimate strength reached 218.22 J/mm3, flexural toughness at 5% strain reached 381.47 J/mm3, and strain at ultimate strength reached 3.50%. Validation experiments confirm the effectiveness of the optimization, with errors below 3.17%.

Optimization of 3D Printing While Traveling En Route to Extend Range of Unmanned Aircraft Systems for Multilocation Mission Scenarios

Abstract The nexus of two relatively recent technologies, additive manufacturing and unmanned aircraft systems (UAS), has enabled new and unique capabilities that have only started to be realized in integrated systems. This article explores and quantifies the impact of 3D printing parts for UAS, or entire UAS systems, on an agent platform, while this agent travels to multiple locations as part of a mission objective. The fully printed or enhanced UAS can then be released at launch points farther away from the goal locations. This, in turn, can accelerate mission completion times and reduce travel costs depending upon the ratio between vehicle speed and 3D printing rate. Thousands of scenarios are optimized across the design space to minimize the travel path length for the agent platform as a result of 3D printing en route to the locations of interest. Results indicate that based on the print capability and agent travel speed, an exponential decay in the amount of travel distance of the agent platform occurs. For unity ratios of print speed and agent speed in the considered design space, a decrease of 55% in the total required distance of our agent is observed. This reduction in total travel distance can reduce time, fuel, cost, and other aspects including other environmental and social impacts. A generalized optimization formulation is also presented at the end to enable similar analyses with other en route range-extending technology such as battery charging.

Anisotropic polymer components with desired elastic properties manufactured through fused filament fabrication additive manufacturing

AbstractFused filament fabrication (FFF) is a popular additive manufacturing (AM) process, primarily used for fabricating polymer components. Optimizing the mechanical properties of FFF components, such as their elastic moduli, is crucial in many applications. This study focuses on adjusting the elastic properties of polymer components manufactured through FFF process by selecting appropriate process parameters. The elastic constants of the anisotropic FFF components are measured by using ultrasonic testing (UT). Response surface methodology (RSM) is employed to determine the optimal settings for these parameters to achieve the desired elastic properties. The effects of layer thickness, printing speed, and raster angle on Young's modulus are explored. Analysis of variance (ANOVA) is used to identify the contributions of each process factor on the output responses. According to ANOVA results, the optimal conditions identified are: a printing speed of 2040 mm/min, a layer thickness of 0.2 mm, and a raster angle of 29°. These conditions collectively achieved the maximum Young's modulus. The differences between the predicted and measured moduli for all responses are less than 5%. The structural factors influencing the results are examined by analyzing the fracture surfaces of the tensile testing (TT) specimens with field emission scanning electron microscopy. Additional measurements of other properties, including ultrasound velocity and wave attenuation, are conducted on the samples. The findings indicate that optimizing the parameters by setting them to their minimum values does not only improve the maximum elastic modulus in specific directions but also reduces attenuation. It is concluded that the desired elastic modulus for a component can be achieved by properly adjusting the process parameters.Highlights Optimizing AM parameters to achieve the desired elastic properties of FFF samples. Examining the effects of each AM parameter by utilizing ANOVA and RSM methods. Measuring the anisotropic elastic properties of AM samples by UT. Verifying UT results through TT and measuring attenuation.

Optimal PLA+ 3D Printing Parameters through Charpy Impact Testing: A Response Surface Methodology

Additive manufacturing (AM) has revolutionized the manufacturing sector, particularly with the advent of 3D printing technology, which allows for the creation of customized, cost-effective, and waste-free products. However, concerns about the strength and reliability of 3D-printed products persist. This study focuses on the impact of three crucial variables—infill density, printing speed, and infill pattern—on the strength of PLA+ 3D-printed products. Our goal is to optimize these parameters to enhance product strength without compromising efficiency. We employed Charpy impact testing and Response Surface Methodology (RSM) to analyze the effects of these variables in combination. Charpy impact testing provides a measure of material toughness, while RSM allows for the optimization of multiple interacting factors. Our experimental design included varying the infill density from low to high values, adjusting printing speeds from 70mm/s to 100mm/s, and using different infill patterns such as cubic and others. Our results show that increasing infill density significantly boosts product strength but also requires more material and longer processing times. Notably, we found that when the infill density exceeds 50%, the printing speed can be increased to 100mm/s without a notable reduction in strength, offering a balance between durability and production efficiency. Additionally, specific infill patterns like cubic provided better strength outcomes compared to others. These findings provide valuable insights for developing stronger and more efficient 3D-printed products using PLA+ materials. By optimizing these parameters, manufacturers can produce high-strength items more efficiently, thereby advancing the capabilities and applications of 3D printing technology in various industries.

Additive manufacturing of copper parts using extrusion and sinter-based technology: evaluation of the influence of printing parameters and debinding method

PurposeThis work is focused on the realization of copper parts using the material extrusion additive manufacturing debinding and sintering (MEX+D&S) technology.Design/methodology/approachA highly filled filament with 90 Wt.% of copper is used to realize nine different combinations varying the printing speed and the flow rate. The following thermal debinding and sintering are performed at 483 °C and 1057 °C, respectively, burying the samples in specific refractory powder and carbon. The green and sintered density are measured and an inspection at optical microscope is implemented for a detailed internal analysis of the defects.FindingsThe samples, that reported the highest values of the green density, become the worst in the sintered condition due to evident swelling defect generated by the entrapped polymer during the thermal debinding. On the other hand, the parts with the lower values of green density allowed to achieve a satisfying density value without significant external defects.Originality/valueThe realization of copper parts through laser-based additive manufacturing technologies shows several troubles related to the rapid heat transfer and the high reflectivity of copper, which is a hinder of the absorption of the laser power. The MEX+D&S becomes an easier and economical alternative for the realization of copper parts. The internal inspection of the samples revealed the need for the improvement on the process chain, adopting a different debinding process to open channels during the thermal debinding to avoid the entrapment of the polymer.

Hardness and microstructure of FDM 3D printed parts using self-made PLA-brass filaments

Technological advancements in the industrial sector have led to rapid developments in 3D printing technology, enabling the creation of three-dimensional prototype models. Various filaments, including polyethylene terephthalate glycol, nylon, and polylactic acid, have been widely adopted in the industry. However, filaments composed of metal mixtures are relatively scarce in Indonesia, primarily available only through select online shops worldwide. The production and sale of such filaments present lucrative opportunities within the manufacturing industry. In this research, an experimental study was conducted to examine the hardness of test specimens fabricated using PLA-brass filament. The objective was to identify the optimal hardness value of the specimens. The study focused on three key parameters: nozzle temperature, layer height, and print speed, each at two different levels. The Taguchi L4(2³) experimental design was employed, along with S/N ratio and ANOVA analysis, to evaluate the results. The findings revealed that specific combinations of parameters yield favorable hardness values, as determined by the Taguchi Method. The optimal set of parameters for achieving good hardness values was determined to be a nozzle temperature of 230°C, a layer height of 0.2 mm, and a print speed of 40 mm/s. These results enhance the understanding of PLA-brass filament properties and facilitate the utilization of 3D printing technology in the manufacturing industry.

3D printable elastomers with exceptional strength and toughness.

Three-dimensional (3D) printing has emerged as an attractive manufacturing technique because of its exceptional freedom in accessing geometrically complex customizable products. Its potential for mass manufacturing, however, is hampered by its low manufacturing efficiency (print speed) and insufficient product quality (mechanical properties). Recent progresses in ultra-fast 3D printing of photo-polymers1-5 have alleviated the issue of manufacturing efficiency, but the mechanical performance of typical printed polymers still falls far behind what is achievable with conventional processing techniques. This is because of the printing requirements that restrict the molecular design towards achieving high mechanical performance. Here we report a 3D photo-printable resin chemistry that yields an elastomer with tensile strength of 94.6 MPa and toughness of 310.4 MJ m-3, both of which far exceed that of any 3D printed elastomer6-10. Mechanistically, this is achieved by the dynamic covalent bonds in the printed polymer that allow network topological reconfiguration. This facilitates the formation of hierarchical hydrogen bonds (in particular, amide hydrogen bonds), micro-phase separation and interpenetration architecture, which contribute synergistically to superior mechanical performance. Our work suggests a brighter future for mass manufacturing using 3D printing.

Growing three-dimensional objects with light

Vat photopolymerization (VP) additive manufacturing enables fabrication of complex 3D objects by using light to selectively cure a liquid resin. Developed in the 1980s, this technique initially had few practical applications due to limitations in print speed and final part material properties. In the four decades since the inception of VP, the field has matured substantially due to simultaneous advances in light delivery, interface design, and materials chemistry. Today, VP materials are used in a variety of practical applications and are produced at industrial scale. In this perspective, we trace the developments that enabled this printing revolution by focusing on the enabling themes of light, interfaces, and materials. We focus on these fundamentals as they relate to continuous liquid interface production (CLIP), but provide context for the broader VP field. We identify the fundamental physics of the printing process and the key breakthroughs that have enabled faster and higher-resolution printing, as well as production of better materials. We show examples of how in situ print process monitoring methods such as optical coherence tomography can drastically improve our understanding of the print process. Finally, we highlight areas of recent development such as multimaterial printing and inorganic material printing that represent the next frontiers in VP methods.

Response of PLA material to 3D printing speeds: A comprehensive examination on mechanical properties and production quality

This study investigates the impact of printing speed on the mechanical properties of parts produced through the fused deposition modeling (FDM) method using a three-dimensional (3D) printer. Tensile test specimens, fabricated with Polylactic Acid (PLA) material on an Ender 3 S1 3D printer, were subjected to varying printing speeds from 15 mm/s to 105 mm/s in 15 mm/s increments, maintaining a 100% infill rate. Detailed measurements of sample masses, hardness values, and surface roughness were conducted to assess the potential effects of printing speed on PLA’s mechanical properties. Porosity values were also calculated to evaluate internal structure homogeneity and void ratios. The results indicate that an increase in printing speed leads to a substantial reduction in production time. For instance, at a speed of 15 mm/s, the printing time was 119 minutes, decreasing to 15 minutes at 105 mm/s. As speed increased, there was a tendency for a decrease in sample masses, with a notable 12% reduction from 8.21 grams at 15 mm/s to 7.21 grams at 105 mm/s. While lower speeds (15 and 30 mm/s) exhibited higher Shore D hardness values, an overall decrease in hardness was observed with increasing speed. Surface roughness showed a proportional increase with printing speed; for example, at 0° angle, the roughness value increased from 0.8 at 15 mm/s to 1.9 at 105 mm/s. Moreover, tensile strength values decreased with higher printing speeds. For samples printed at 15 mm/s, the tensile strength was 60 MPa, decreasing to 44 MPa at 105 mm/s, representing a 27% reduction. These numerical findings underscore the significant influence of 3D printing speed on both production efficiency and the mechanical properties of the printed material.

Fiber bundle deposition model and variable speed printing strategy for in-situ impregnation 3D printing of continuous fiber reinforced thermoplastic composites

In the in-situ impregnation 3D printing of continuous fiber reinforced thermoplastic composites (CFRTPCs) at constant printing speed, in order to pursue higher printing efficiency, a higher speed for printing is adopted generally, which has no effect on the printing of the straight section, but at the same speed of printing at the corner, the printing speed will cause the fiber bundle to deviate from the printing path at the corner, which affects the accurate laying of fiber bundle along the printing path. Obviously, reducing the printing speed is an effective method to improve the print quality at the turn, but printing the entire part at the reduced speed will greatly limit the overall printing speed. However, the problem of different corner angles and shifting points from the straight section of high-speed printing to the corner section of low-speed printing has been puzzling researchers. In this paper, a fiber bundle deposition model has been proposed to reveal the deposition of fiber bundles, and the maximum offsets of fiber bundles were predicted under different turning angles. Compared with the measured results, the prediction error at different turning angles ranged from −1.07 % to 10.30 %. Then, combining with the finite element analysis method, the fiber bundle deposition model was adopted to study the effects of printing speeds, and the maximum printing speeds for different printing angles and the variable printing speed strategy have been put forward. The results have revealed that, by using the optimized variable printing speed strategy, the surface quality of the fabricated parts and the deposition of the fiber bundles along the designed printing path were significantly improved. The fiber bundle deposition model and the variable speed printing strategy could be helpful for the high-precision 3D printing of CFRTPCs.

Ceramic fused filament fabrication (CF3) of alumina: Influence of powder particle morphology on processing and microstructure

This study investigates ceramic fused filament fabrication (CF3) 3D printing of alumina with an emphasis on the impact of particle morphology on feedstock preparation and printability. Spherical powder displayed superior flow with higher apparent density, tap density, and powder packing fraction compared to irregular powder. A 55 vol % powder loading was chosen to ensure good flowability during printing. Irregular powder-based feedstocks had 40X higher viscosity than spherical powder feedstocks at 400 s−1 shear rate, posing potential printing challenges. Slow printing speed maintained low feed-rates for consistent material flow. The debinding and sintering process produced macroscopically defect-free alumina components with relative densities above 89 % for both powder morphologies. The focus of the work is on comparing two different powder particle morphologies influencing feedstock behavior, printing fidelity, and sintered part properties.

A study of the temperature-dependent stress yielding behavior of a gelatin-based hydrogel ink and its effects on the enhancement of the 3D printing resolution

Though existing studies had continuously improved the hydrogel printing resolution by facilitating ink solidification, it was literally challenging to exceed the size limit of the printing needle even if there was an ideal ink that could solidify instantaneously. One possible solution to this hurdle is to stretch the hydrogel ink with a high printing speed and try maintaining its deformation without strain recovery. In this study, a gelatin/alginate/hydroxyapatite(HA) ink was printed at multiple temperatures, and a much lower yielding strain occurred at −1 °C than 2–5 °C according to our rheological tests. At −1 °C, the hydrogel ink could be highly stretched to produce an ultrahigh resolution at 81 ± 13 μm while maintaining uniform and continuous. Furthermore, our biological tests found a high scaffold resolution greatly promoted cell adhesion, proliferation, osteogenic differentiation and biomineralization. We stepped further from existing studies, by coming up with a new concept of utilizing ink stress-yielding in improving printing resolution, which would broaden our understanding to the processing-structure-property relationship in hydrogel-based 3D printing.