Movable Type Research Articles

A Study of Fit and Friction Force as a Function of the Printing Process for FFF 3D-Printed Piston–Cylinder Assembly

Current 3D printing processes for polymer material extrusion are limited in their accuracy in terms of dimension, form, and position. For precise results, post-processing is recommended, like with assembled parts such as pistons and cylinders wherein axial mobility is desired with low friction force and limited radial play. When no post-processing step of the printed parts is accomplished, the fit and the friction force behavior are strongly dependent on the process performances. This paper presents a study on parameters of significance and their effects on sliding and running fits as well as their friction forces for fused filament fabrication of such assemblies. A series of experiments were performed with multiple factors and levels, including the position or layout of printed objects, their layer thickness, the material used, the use of aligned or random seam, and the printer type. Piston–cylinder pairs were printed, measured, assembled, and tested using a tensile test frame. A mathematical model was developed to describe the oscillating friction force behavior observed. This study presents the feasibility and limitations of producing piston–cylinder assemblies with reduced play and friction when using appropriate conditions. It also provides recommendations to obtain and better control a desired running and sliding fit.

Atomic Printing Strategy Achieves Precise Anchoring of Dual-Copper Atoms on C2N Structure for Efficient CO2 Reduction to Ethylene.

Isolated metal sites catalysts (IMSCs) play crucial role in electrochemical CO2 reduction, with potential industrial applications. However, tunable synthesis strategies for IMSCs are limited. Herein, we present an atomic printing strategy that draws inspiration from the ancient Chinese "movable-type printing technology". Selecting customizable combinations of metal atoms as metal precursors from an extensive binuclear metal library. A series of dual-atom catalysts were prepared by utilizing the edge nitrogen atoms in the C2N cavity as anchoring "pincers" to capture metal atoms. To prove utility, the dual atom catalyst Cu2-C2N is investigated as electrocatalytic CO2RR catalyst. The synergistic interaction of dual Cu atoms promotes C-C coupling and guarantees FEC2+ (90.8 %) and FEC2H4. (71.7 %) at -1.10 V vs RHE. DFT calculations revealed the Cu2 site would be subtly flipped during CO2RR for enhancing *CO adsorption and dimerization. We validate that atomic printing strategies are applicable to wide range of metal combinations, representing a significant advancement in the development of IMSCs.

A Global Snapshot of 3D-Printed Buildings: Uncovering Robotic-Oriented Fabrication Strategies

This paper aims to provide a global snapshot of concrete 3D-printed buildings and to uncover robotic-oriented large-scale fabrication strategies. Therefore, an extensive internet search and literature review was carried out to investigate 3D-printed buildings. In this study, 154 construction projects with 204 buildings were systematically recorded and evaluated from 2013 up to 2023. Using an exploratory mixed-methods approach and a comparative case study analysis, a total of 88 3D-printed buildings were first evaluated descriptively. Thereafter, different existing printing strategies for in situ, on-site, and off-site production were identified, using an iterative approach. In addition to the geographical distribution, the descriptive evaluation also showed the key players as drivers for the spread of the 3D-printing technology and the correlations between printer type, fabrication strategy, and the building size. With regard to the printing strategy, three different approaches for in situ and off-site fabrication can be defined, depending on the printer types and their characteristics (work size and mobility): print-in-one-go, horizontal or vertical segmentation, and the multi-element vs. full-scaled wall strategy. However, the study showed that the data quality was sometimes difficult due to a lack of information and essential details of the printing process and segmentation.

Evaluation of wash colour strength of a printed garment with flexible filaments on 3D printers

The research aims to evaluate the solidity of the washing colour of a garment printed with flexible filaments on 3D printers. Three groups of factors have been selected: Anet A8 and M3D Crane Quad printer, temperature (49° and 71°C) and flexible filaments TPE (thermoplastic elastomer) and TPU (polyurethane thermoplastic), framed in the factorial design, type applied of 10 units per combination of factors in a total of 80 sampling units, using Girowah equipment according to the technical standard AATCC TM61-2020. The results show that the printer factors Anet A8 and M3D Crane Quad with the CIELab and CMC (2:1) discolouration system exceed 50% in both the tolerances of the value 1. About the temperature factor (49° and 71°C), which exhibits a discolouration of 1.06 in CIE94 and 1.36 in CMC, it is determined that the combination with better resistance to discolouration of solidity at washing (CIE94 - 49°C) compared to CMC (2:1) better establishes the visual and technical concordance of the solidity of colour. As regards flexible filament types: TPE and TPU, the results show us that the colour tolerance assessments (CIELab CIE94) and (CMC (2,1)) prove that the TPE filament has greater resistance to the discoloration of the 3D-printed garment at different temperatures. In conclusion, the solidity of colour washing in a printed garment with flexible filaments in a 3D printer causes discolouration by the minimum, be it the factors of printer type, filament, and temperature. There is a need for analysis with other values and it remains open to other research.

Parallel molecular data storage by printing epigenetic bits on DNA

DNA storage has shown potential to transcend current silicon-based data storage technologies in storage density, longevity and energy consumption1–3. However, writing large-scale data directly into DNA sequences by de novo synthesis remains uneconomical in time and cost4. We present an alternative, parallel strategy that enables the writing of arbitrary data on DNA using premade nucleic acids. Through self-assembly guided enzymatic methylation, epigenetic modifications, as information bits, can be introduced precisely onto universal DNA templates to enact molecular movable-type printing. By programming with a finite set of 700 DNA movable types and five templates, we achieved the synthesis-free writing of approximately 275,000 bits on an automated platform with 350 bits written per reaction. The data encoded in complex epigenetic patterns were retrieved high-throughput by nanopore sequencing, and algorithms were developed to finely resolve 240 modification patterns per sequencing reaction. With the epigenetic information bits framework, distributed and bespoke DNA storage was implemented by 60 volunteers lacking professional biolab experience. Our framework presents a new modality of DNA data storage that is parallel, programmable, stable and scalable. Such an unconventional modality opens up avenues towards practical data storage and dual-mode data functions in biomolecular systems.

Comparison of mechanical properties of 3D printer resins for occlusal splints using different models of 3D printers.

Considering the development of new 3D printing technologies that use different printing techniques, further studies must be conducted to evaluate the impact of different printing systems on the mechanical properties of 3D-printed materials. This study aimed to evaluate the mechanical properties of 3D-printed materials for occlusal devices using different 3D printers and printing layer thicknesses. Ninety rectangular samples were manufactured and divided into nine groups according to the 3D printer model they were printed on (AnyCubic Mono X, Elegoo Mars 2, or FlashForge Hunter) and the layer thickness (20, 50, or 100 µm) and were subjected to superficial microhardness, flexural resistance, and elasticity modulus tests. The results were analyzed using two-way analysis of variance and Tukey's statistical tests, with a significance level of 5%. The type of 3D printer significantly affected superficial microhardness (p = 0.007). Flexural strength showed a significant interaction between the 3D printer and layer thickness (p = 0.005), with both factors independently influencing flexural strength (printer: p< 0.001, layer thickness: p< 0.001). Elasticity modulus was significantly influenced by the 3D printer type (p< 0.001) and the interaction between both factors (p = 0.004). The AnyCubic Mono X 3D printer with a 20 µm layer thickness exhibited more consistent mechanical properties than the other printers. Variations in printing systems and layer thicknesses can impact the mechanical properties of 3D-printed materials. Key words:CAD-CAM. Bruxism. Temporomandibular disorders. Mechanical tests; 3-D printing.Care Team.

Investigation of process parameters of electrohydrodynamic jetting for 3D printed PCL fibrous scaffolds with complex geometries

Tissue engineering is a promising technology in the field of regenerative medicine with its potential to create tissues de novo. Though there has been a good progress in this field so far, there still exists the challenge of providing a 3D micro-architecture to the artificial tissue construct, to mimic the native cell or tissue environment. Both 3D printing and 3D bioprinting are looked upon as an excellent solution due to their capabilities of mimicking the native tissue architecture layer-by-layer with high precision and appreciable resolution. Electrohydrodynamic jetting (E-jetting) is one type of 3D printing, in which, a high electric voltage is applied between the extruding nozzle and the substrate in order to print highly controlled fibres. In this study, an E-jetting system was developed in-house for the purpose of 3D printing of fibrous scaffolds. The effect of various E-jetting parameters, namely the supply voltage, solution concentration, nozzle-to-substrate distance, stage (printing) speed and solution dispensing feed rate on the diameter of printed fibres were studied at the first stage. Optimized parameters were then used to print Polycaprolactone (PCL) scaffolds of highly complex geometries, i.e., semi-lunar and spiral geometries, with the aim of demonstrating the flexibility and capability of the system to fabricate complex geometry scaffolds and biomimic the complex 3D micro-architecture of native tissue environment. The spiral geometry is expected to result in better cell migration during cell culture and tissue maturation.

Preliminary analysis on the characteristics of stamps by 3D printing and their stamped impression

The development of 3D printing technology has brought new risks and challenges to stamp impression identification. To prevent potential risks, a total of 45 stamps were printed using three types of 3D printers: fused deposition molding (FDM) printer, stereo lithography (SLA) printer, and liquid crystal display (LCD)-based SLA 3D printer, including 6 stamps replicated using LCD-based SLA 3D printer. A preliminary study was conducted on the printed stamps and stamped impressions, and the results showed that stamp are influenced by various factors such as printer type, printing material, the technology level of the producer, mold parameters such as font, size, printing parameters, slicing direction, and polishing process, etc., resulting in significant differences in characteristics. However, there are some obviously common characteristics such as missing of strokes, exposure of white and mottled phenomenon in the impression stamped by the 3D produced stamp. The impression of stamp replicated with an LCD 3D printer can be easily identified since it is difficult to achieve consistency with the real impression in detail characteristics.

Assessment of lip and finger print patterns in patients with type 2 diabetes mellitus and dental caries: A cross-sectional study

Abstract Background and Objectives: Globally, the prevalence of diabetes and dental caries has been soaring high in recent times. There is a constant effort in the scientific community to develop a reliable and economic early predictor which can serve the purpose of mass screening of genetically vulnerable populations. The present study attempts to evaluate the different types of lip prints and finger prints in diabetes mellitus and dental caries and to see association between the most common diseases (diabetes mellitus and dental caries) if any. Materials and Methods: Study subjects included 100 subjects (50 uncontrolled Type II diabetes mellitus patients and 50 healthy controls) in the age group of 30–80 years among the population of Lucknow. Lip prints were obtained using lipstick and cellophane paper, analysed, and classified using Suzuki and Tsuchihashi’s classification. Finger prints were obtained using inkpad, analysed, and classified using Henry’s system of classification. Results: We found loop-type fingerprints and type IV lip prints associated with diabetic patients. Non-diabetics showed loop-type fingerprints and type I lip prints. We found increased dental caries incidence (DMFT scores) in diabetics. Diabetic subjects with caries showed loop fingerprints, which reiterated our earlier findings but are not associated with type IV lip prints. Non-diabetics with caries showed arch fingerprints, but they are not associated with type I lip prints. We found that DMFT scores that we used to assess caries did not associate well with lip prints. Conclusion: The results from our study strongly suggest that dermatoglyphics can be used as a non-invasive technique to mass screen for diabetes as well as dental caries as both diseases are predominantly associated with loop-type fingerprints. Type IV lip prints could be used to screen for diabetes, but no association of lip prints was seen in patients with caries.

Digital Revolution and Artificial Intelligence as Challenges for Today/Rewolucja cyfrowa i sztuczna inteligencja jako wyzwania współczesności

This article addresses the social impact of the ongoing digital revolution through a critical analysis of the literature on the subject. The aim is to understand the dynamics of change, which is key to dealing with the complexities of the digital age and realising its potential for sustainable development. The information revolution and artificial intelligence pose significant challenges to modern society by marking a profound transformation through self-organising social changes that disrupt existing norms. The digital age has revolutionized information systems, much like Gutenberg's invention of movable-type printing press. While it enables scientific and economic progress, the information revolution raises ethical, moral and legal concerns. Social media have become ”weapons” in a hybrid conflict, where the intangible battleground is human cognitive systems.

Sandwich structures with TPMS core and printed circuit board faces

Sandwich structures are widely used in the aerospace industries due to their mechanical properties that give them high energy absorption, low density, and high mechanical strength. These structures are composed of two faces interspersed by a core that can have various geometric configurations. One of the most widely used geometric cells are honeycomb structures, highly used in structural applications since the early 20th century. However, new geometric core configurations, as well as alternative materials and manufacturing processes, are being studied for space applications. Triply Periodic Minimal Surfaces (TPMS) are lattice structures composed of periodic surface structures in three independent directions. Among the available models, the most notable TPMS structures are Schwartz-type, Diamond-type, and Gyroid-type. Since the structures are too complex to be manufactured by subtractive manufacturing, additive manufacturing is excellent, being able to produce complex structures much faster and easier. One of the most common types of 3D printing is Fused Deposition Modeling (FDM), which is based on the fusion and deposition of various materials, such as thermoplastic materials. To save space and improve the mechanical strength of Cubesats, sandwich structures are being produced using printed circuit boards (PCB) of electrical and electronic components as outer faces. These faces are called laminates and are made of thermosetting materials such as fiberglass and epoxy resin, composites, or ceramic materials. The objective of this paper is to produce sandwich panels, with a core based on the TPMS architecture. They will be printed in thermoplastic material with laminated faces used in printed circuit boards. A numerical analysis using the finite element method was performed and its testing according to ASTM C393, furthermore, this paper aims to realize an optimized TPMS core with mass distribution based on the stress profile and compare them.

The evolution of printing

The history of printing is a captivating narrative that has significantly influenced the dissemination of knowledge and the development of human society. This article explores the prehistory of literacy, the emergence of writing systems, the tools used before the invention of printing, and the profound impact of Johannes Gutenberg's movable type printing press. It also discusses the challenges faced by printing technology over the centuries, the role of digitalization, and the enduring value of traditional printing.

Effect of printing technology and orientation on the accuracy of three-dimensional printed retainers.

To evaluate the impact of printer technology and print orientation on the accuracy of directly printed retainers. Digital retainers were printed with two different printing technologies: digital light processing (DLP) and stereolithography (SLA), using two different orientations: 0° and 90°. After printing, the retainers (n = 40) were scanned using cone-beam computed tomography. The DICOM files were then converted into standard tessellation language (STL) files. Comparison of the printed retainers with a master file was done by superimposition using a three-dimensional (3D) best-fit tool in Geomagic software. A ±0.25 mm tolerance was set to detect differences between the superimposed files. Statistical analysis was conducted (Kruskal-Wallis and Wilcoxon-Mann-Whitney tests, with Bonferroni correction). The lowest median average deviation was observed for the DLP horizontally printed models (median, [interquartile range (IQR)] = 0.01 mm, [-0.01, 0.02]) followed by the SLA horizontally printed retainers (median, [IQR] = 0.05 mm, [0.03, 0.07]). The highest median inside the tolerance levels ratio was observed for the horizontally SLA printed retainers (median, [IQR] = 78.9%, [74.4, 82.4%]) followed by the horizontally DLP printed retainers (median, [IQR] = 78.2%, [74.5, 80.7%]). Both technologies (DLP and SLA) showed 3D printed results compatible with orthodontic clinical needs. Printing orientation was more important than printer type regarding its accuracy. Additional studies are needed to evaluate the accuracy of direct printed appliances clinically.

Application of innovative mechatronic systems in product design, development and production

The application of mechatronic systems is very topical today. Today, mechatronic systems are applied in all areas, so today systems are also being developed that enable fast and simple production of products. Today's mechatronic systems that are supported by computers enable the development, easy and fast production of prototypes and products. Two technologies that are widely used are 3D printers and scanners. 3D printers allow a virtually developed product to be turned into a physical model, while the application of a 3D scanner allows a physical model to be turned into a virtual model on a computer. In this paper, a comparative analysis of two types of printers and their software was performed. They differ according to their working principle. In addition to the working principle, an example of the difference between the software used to write the G code to drive the printing process of 3D printer.

Enhancing sustainability in polymer 3D printing via fusion filament fabrication through integration of by-products in powder form: mechanical and thermal characterization

FFF (fused filament fabrication) is a type of 3D printing that utilizes filament for part creation. This study proposes using by-products or waste to replace part of the plastic in FFF filament, reducing environmental impact. The aim is to maintain a simple manufacturing process involving extrusion on a single-screw desktop machine followed by printing. The plastic matrix comprises polylactic acid (PLA) and polyethylene glycol (PETG), with added powdered by-products: seashells, car glass and mill scale (metal). Additives will be incorporated at 10% and 20% by weight, with two grain sizes: up to 0.09 mm and up to 0.018 mm. Mechanical tests (tensile, flexural and hardness) and thermal characterization tests will be conducted. Findings suggest adding 10%w powder of any variety to PETG increases tensile strength up to 48%, with metal powder (mill scale) showing the highest enhancement, even at 20%w, resulting in a 41% increase. Conversely, adding powder to PLA worsens mechanical properties without stiffening the material; instead, the elastic modulus decreases. Metal grain size has minimal impact, with grain sizes lower than 0.09 mm optimal for PLA. Thermal conductivity in polymers blended with powder additives is lower than in virgin polymers, likely due to air void formation, supported by density and microscopic evaluations. This research underscores the potential of utilizing waste materials with a simple FFF filament production to enhance sustainability in 3D printing practices.

Virtual display of wooden furniture cultural relics based on laser and CT scanning technology

The 3D reconstruction and virtual display of wooden furniture cultural relics were investigated using laser scanning and CT scanning techniques. The suitability of different 3D reconstruction techniques and virtual display approaches were considered. The experiments demonstrated that digital models obtained from both laser scanning and CT scanning can be integrated seamlessly into virtual environments created with 3DMAX for exhibition purposes. Additionally, post-processing software, such as PR or AE, can be utilized to synthesize virtual display video. The resulting images exhibit self-adaptation capabilities, with clear and undistorted 3D model and texture image. Moreover, other types of scanned models are suitable for 3D micro-scale model printing, although CT-based models tend to achieve higher printing accuracy compared to those generated by laser scanning technology. However, the precision of 3D printing model is contingent upon factors such as the precision of digital model, the type of printer, and the printing material.

Unveiling Cross-Cultural Hidden Nexus: An Analysis of Chinas Contribution to the Cultural Influence of the East on the West

Even though the cultural communication between Japan and Europe is massively documented, such as the impact of ukiyo-e prints on Impressionism, Chinese culture's enormous contributions are overlooked. Ukiyo-e is often regarded as the primary source that influenced Impressionism from the East during the Meiji Restoration in the fin de sicle. The East's impact on the West is long-lasting rather than explosive. The critical power of traditional Chinese art and innovations, for example, the moveable type printing, over the evolution of European art movements has yet to be noticed due to political and geographic limitations. Citing paintings by Ma Yuan (1160-1225), Li Song ( active 1190-1230) and Wang Ximeng (1096-1119) in China, Katsushika Hokusai (1760-1849), Utagawa Kuniyoshi (1798- 1861), and Hiroshige (1797- 1858) in Japan, Vincent Van Gogh (1853- 1890) in the Netherlands, and Claude Monet (1840-1926) in France, among others, as examples of specific comparisons and cultural analyses, this article delves into the hidden connections and cultural exchanges, through working on the technical and iconographical forms from ancient China that shaped the European art in the epoch of high modernism.

Boundary Gaussian Distance Loss Function for Enhancing Character Extraction from High-Resolution Scans of Ancient Metal-Type Printed Books

This paper introduces a novel loss function, the boundary Gaussian distance loss, designed to enhance character segmentation in high-resolution scans of old metal-type printed documents. Despite various printing defects caused by low-quality printing technology in the 14th and 15th centuries, the proposed loss function allows the segmentation network to accurately extract character strokes that can be attributed to the typeface of the movable metal type used for printing. Our method calculates deviation between the boundary of predicted character strokes and the counterpart of the ground-truth strokes. Diverging from traditional Euclidean distance metrics, our approach determines the deviation indirectly utilizing boundary pixel-value difference over a Gaussian-smoothed version of the stroke boundary. This approach helps extract characters with smooth boundaries efficiently. Through experiments, it is confirmed that the proposed method not only smoothens stroke boundaries in character extraction, but also effectively eliminates noise and outliers, significantly improving the clarity and accuracy of the segmentation process.

Comparative study to evaluate the subtractive and additive process in dentistry: a systematic review

The objective of this study was focused on carrying out an analysis on the main contributions of additive manufacturing in dental pieces and the benefits of this procedure in dentistry, as well as establishing the advantages and limitations that this modality entails. The research was based on a systematic review with adaptability to Prisma and Tranfield methodology, through which the impact of additive manufacturing in dental clinics and in the various clients who acquire the pieces in terms of taste and adherence to product, likewise, in terms of contribution to knowledge, the study remains as a precedent for other investigations that are carried out later on this topic. Articles published in the last five years from the Scopus and Web of Science databases were reviewed. The process was developed through inclusion and exclusion criteria, wherein its final instance the material criteria, type of printing, and post-processing were reviewed, to which a final filter was made that yielded the articles for review of the literature. This project contributes to the knowledge of the processes that are carried out in additive manufacturing in dental pieces, the advantages and disadvantages, thus leaving a precedent for the adherence of dental clinics to this method.

4D Printing of novel poly(ethylene-vinyl acetate) / poly(butyl methacrylate-co-isobutyl methacrylate) shape memory polymer blends

4D printing is a technology that combines additive manufacturing with shape memory polymers, aiming to enhance the functionality of 3D printed structures. Filaments made from thermoplastic polymers are commonly used in Fused Deposition Modeling (FDM), which is one of the most prevalent types of 3D printing. Here, novel heat-responsive shape memory polymer blends were produced from ethylene-vinyl acetate copolymer (EVA) and poly(butyl methacrylate-co-isobutyl metacrylate) polymers. The effect of blend composition on the morphological, thermal, mechanical, and shape memory properties was investigated. The blend (60E-40B) containing 60 % by weight EVA and 40 % by weight BMA-co-iBMA exhibited optimum shape memory performance with a shape fixing (Rf) of 94.1 % and a shape recovery (Rr) of 94.5 % at a shape transition temperature (Ttrans) of 55 °C. Filament for the 60E-40B blend was produced for FDM type 3D printers, and 4D parts for various applications were printed using this filament. These 4D printed parts, designed for robotic grippers, self-assemble rivets, movable cog-wheel teeth, surface traps, and finger splints, displayed shape recovery characteristics in both hot oven and hot water environments.