Digital Printing Research Articles

Digital light processing printing of porous ceramics using interparticle photo-cross-linkable Pickering emulsions

Digital light processing (DLP) printing using photo-curable Pickering emulsion is a promising route to fabricate porous ceramics having on-demand structures. However, the long duration for debinding/sintering due to the large organic contents remained in the photo-cured bodies and the insufficient long-term stability of the emulsions needs to be solved toward efficient manufacturing. Herein, a new interparticle photo-cross-linkable Pickering emulsion having improved stability, which can be photo-cured using reduced amounts of monomers, were designed for the rapid production of porous ceramics using DLP printing. The Pickering emulsion was obtained by mixing isopropyl myristate into a dimethyl sulfoxide (DMSO) aqueous suspension of SiO2 particles with pre-dissolved polyethylene glycol diacrylate (PEGDA) and a photo-radical initiator. Further, functionalized polyethyleneimine (PEI) was designed to ensure the dispersion of SiO2 particles and formation of a Pickering emulsion. The photo-irradiation of the designed Pickering emulsion resulted in the successful photo-curing by the radical polymerization of PEGDA, followed by a Michael addition reaction between the reactive amine of PEI and acryloyl groups of PEGDA. The improved stability of the emulsion over time and reduced amounts of monomer facilitated the application of the designed emulsion to DLP printing, followed by a rapid firing process without any structural collapse.

Novel D-π-A hemicyanine dye as photoinitiators for insitu hydrogel formation and DLP printing.

The field of biofabrication imposes stringent requirements on the polymerization activity and biosafety of photopolymeric hydrogel systems. In this investigation, we designed and synthesized four hemicyanine dyes with a D-π-A structure specifically tailored for biofabrication purposes. These novel dyes, incorporating carbazole (CZ), triphenylamine (TPA), anthracene (AN), and benzodithiophene (BDT) as electron donors, along with heterocyclic salt (IN) as electron acceptors, were prepared using a straightforward synthesis method. The absorption maxima of ANIN, CZIN, and TPAIN exceeded 500 nm, rendering them suitable co-initiators for the free radical photopolymerization of acrylates under green-red light exposure facilitated by light-emitting diodes (LEDs) and the co-initiator iodonium salt (ION). Notably, CZIN and TPAIN, due to their robust dye absorption and efficient electron transfer to ION, functioned as high-performance photosensitizers. Meanwhile, BDTIN, with its strong and broad absorption range (400-600 nm), enhanced the accuracy of visible light photopolymerization. These dyes exhibit characteristics such as facile synthesis, heightened photo stability, and non-toxicity and also demonstrate the ability to discern the alkalinity of a solution to some extent. Furthermore, we explored the application of these hemicyanine dyes in 3D printing, showing potential to enhance printing resolution in DLP 3D printing (digital light process 3D printing).

DESIGN DEVELOPMENT AND DIGITAL PRINTING OF HOME FURNISHING ARTICLES USING “AQUATIC MOTIFS”

Textile designing is the most demanding and emerging field as it is full of scope and creativity but many individuals become quite lost when confronted with the task of finding “inspiration” any objects or thing we see in our daily routine are possible design sources. The sources of inspiration play a powerful role in the beginning of the design process and research and strategic collection planning. This study investigated the use of aquatic motifs on home furnishing items using digital printing, exploring their potential for product diversification and consumer acceptance. Fifteen captivating designs featuring aquatic themes were created for bed sheets, table covers with mats, and cushion covers using two designing software Corel Draw and Adobe Photoshop. A panel of thirty judges including renowned local designers and discerning boutique owners evaluated the developed designs for the selection of two most enthralling designs from each category for application on textiles in order to prepare home furnishing articles. Their enthusiastic response highlights the positive reception of the aquatic motifs. It concludes that use of aquatic motifs on home furnishing items using digital printing has paved the way for wide new world of product diversification in the home furnishing market.

Aesthetic relationship between personality emotions and contemporary graphic design patterns on the surfaces of textiles

In this work, five different types of animated graphic design ideas (traditional, 2D, 3D, stop motion, motion) were examined on three different textile fabrics (cotton, silk, polyester) through digital printing. Psychological-emotional expressions (openness, conscientiousness, extroversions, agreeableness, and neuroticism) were investigated that influenced the perceptual criteria. Lastly, a quantitative investigation was carried out from a sample of 300 students whose ages varied from 20 to 24 years old for an analysis of aesthetic appeal through a 5-point Likert scale. The results revealed that motion animation design has the most effective aesthetic appeal while the stop motion design pattern has the least aesthetic appeal. Silk fabric samples have better graphic consequences whereas polyester fabric samples have the least. Moreover, individuals with neuroticism emotional personality have the least effective response while agreeableness has the utmost for the sense of aesthetics. 71% of students were accustomed to aesthetic appeal as compared to structural fabrics.

Synthesis of nonionic polyacrylate emulsions: coatings for digital inkjet printing

Synthesis of nonionic polyacrylate emulsions: coatings for digital inkjet printing

Excellent microwave absorption property of 3D printed SiCN matrix metamaterial

The combination of 3D printing, polymer derived ceramics, and electromagnetic wave (EMW) absorption metamaterials is particularly useful for spacecraft stealth in extreme environments and is gradually gaining significant interest. While the 3D printing of SiOC has been extensively researched, the high temperature stability and mechanical performance of SiOC are not as favorable as SiCN. However, it remains challenging to prepare SiCN metamaterials with both high mechanical and microwave absorption properties by 3D printing. Herein, we demonstrate a SiCN EMW absorption metamaterial with high mechanical properties using digital light processing 3D printing, which achieves a minimum reflection loss of −31.01 dB (99.9 % absorption), and the widest effective absorption bandwidth covers the entire X-band from 8.2 to 12.4 GHz. And the EMW absorption performance can be adjusted based on the size of the unit structure.

High-Resolution Printing of Various Electronic Materials by Electrophotography

Electrophotography is a digital, on-demand, dry, and page printing technique that operates based on toner particles of electronic materials using an electrostatic force and generates an electrical circuit via distribution of the toner particles. We developed a 10 μm linewidth resolution with various electronic materials, including conductors, semiconductors, and insulators, without any chemical pretreatments on the substrate films, while a 5 μm resolution was also possible for limited materials. The electrical resistivity of the printed Ag–Ni after an intense pulse light sintering was comparable to that of commercial indium tin oxide transparent films.

Investigation of sound absorption on a polymeric acoustic metamaterial using 3D printing process

AbstractThis paper presents the design and characterization of DENORMS (Designs for Noise‐Reducing Materials and Structures) cell‐based acoustic metamaterial developed using a 3D printing technique. The metamaterial's acoustic absorption properties were investigated through experimental testing and numerical simulations. The experimental testing of the acoustic metamaterial was conducted in an impedance tube using a two‐microphone method. The numerical simulations were carried out using a thermoviscous module. The simulations allowed for a deeper understanding of the influence of geometric parameters on the absorption coefficient, providing valuable insights for optimizing the design. It was observed that upon increasing the spherical diameter while maintaining the same cylindrical diameter and cylindrical length resulted in an increase in the absorption coefficient throughout the frequency range. It was also observed that upon increasing the cylindrical diameter, there was a significant decrement of absorption coefficient, and upon increasing the length of the cylinder, there was a shift of response toward lower frequency. The augmentation in cell count from 9 to 24 led to a rise in the absorption coefficient and a shift of the response toward lower frequencies. The findings highlight the significance of photopolymer 3D printing in tailoring complex geometries for enhanced performance of the acoustic metamaterial.Highlights Photopolymeric resin used for DENORMS cell‐based acoustic metamaterial. High cleanability and accuracy of digital light processing 3D printing technique. Usage of thermoviscous model for simulation of sound absorption behavior. Use of two microphone impedance tube to determine sound absorption coefficient. Geometric parameters significantly affect the absorption coefficient.

Architectural Taste: Shaping Aesthetics, Embracing Multisensory Experiences, and Navigating Cultural Influences

This paper explores the intricate relationship between architecture and taste, focusing on mechanisms that enable architecture to enhance aesthetic preferences and sensory experiences. It delves into the impact of architecture on taste through the education of public taste, the development of interactive models, and the establishment of an architectonic language of communication. These mechanisms serve as vehicles to broaden public appreciation, deepen individual understanding, and personalize architectural aesthetics. The research investigates the potential for architecture to extend beyond the visual by integrating touch, taste, and smell, providing a more inclusive, multisensory experience. It examines how digital modeling, 3D printing, and edible materials can be utilized to season and flavor the built environment, making it uniquely immersive and responsive to personal taste. Furthermore, the study acknowledges the influence of socio-cultural and economic factors on architectural preferences and the importance of catering to diverse tastes. Employing qualitative methods, this research contributes insights from discussions that reveal the evolving nature of architecture's role in shaping taste. Findings underscore architecture's capacity to evolve as a medium for cultural expression, fostering inclusivity, emotional resonance, and dynamic adaptation in the built environment. These insights offer valuable perspectives for architects, designers, and policymakers as they strive to create spaces that reflect the diverse tastes and preferences of society

Experimental investigation and optimization of process parameters on digital light processing (DLP) 3D printing process based on Taguchi-grey relational analysis

Additive manufacturing technology, specifically Digital Light Processing (DLP), offers a unique approach to fabricating intricate objects without the need for traditional molds or machining. The technique described entails the incremental construction of layers through the curing process polymer, facilitated by a projection light source. Digital Light Processing 3D printing is particularly suited for creating complex structures with small cross-sections, requiring high surface polish and durability. In this study, DLP-printed test coupons were produced using an Ultraviolet-sensitive resin, and the investigation focused on examining the impact of surface quality and toughness, adhering to guidelines outlined by the ASTM specifications. To optimize the DLP printing process, Taguchi and Grey relational optimization techniques were employed to find the best values for multiple factors. The parameters considered in this study were speed, layer thickness, orientation, and pattern type. By employing these techniques, the optimal parameters were identified as follows: The printing process is conducted at a speed of 3 mm per second, with each layer being 0.05 mm thick and the orientation of the printed object is set at 90 degrees, and the pattern employed is of the square type. Experimental results revealed that utilizing these parameters yielded a surface roughness of 2.58 µm and an impact strength of 9.1J. The results showed that the Grey relational grade improved from 0.6244 to 0.7974, with a deviation of 0.173 and 27.71%, indicating a significant enhancement in the optimization process. Additionally, contour plots depicting the relationships between speed and orientation, speed and layer thickness, and orientation and layer thickness were generated for surface roughness, impact strength, and the Grey relational grade. This research offers valuable insights into optimizing DLP 3D printing processes to achieve enhanced surface quality, toughness, and material efficiency while reducing costs and production time.

Optimizing Workflow Efficiency in Digital Printing Imposition: A Visual Tutorial on Design Impact Printing Methods

The rapid evolution of digital printing technologies has necessitated a parallel advancement in imposition workflows to ensure maximum efficiency, cost-effectiveness, and high-quality results. The purpose of this study sought to outline a visual tutorial focused on the intersection of design impact and workflow optimization in the realm of digital printing imposition. In an attempt, the study demonstrated the benefits of template-based imposition for standardized layouts and design consistency using imposer pro software. As a qualitative research method, the study adopted case study design on a visual tutorial approach, utilizing a combination of images, diagrams, and video explanatory text to present step-by-step guides and examples. The content was structured to cover fundamental concepts, software selection, template-based imposition, automation and variable data printing (VDP) integration. The outcome of the study revealed that the tutorial's visual format effectively communicated the intricacies of optimizing workflow efficiency in digital printing imposition. The study encourages design practitioners to leverage the tutorial as a practical resource for achieving efficiency gains, reducing turnaround times, and elevating design impact in the rapidly evolving digital printing landscape.

Characterization of Bixin by UV-Visible Spectroscopy and HPLC, and Its Application as Latent Fingermark Developer

Fingerprints are essential for human identification and are valuable tools in criminal investigations. The pursuit of new materials for digital printing is expanding, with increasing interest in natural compounds such as bixin, sourced from annatto seeds. Despite its traditional use as a natural dye with medicinal properties, the potential of bixin in papilloscopy remains largely untapped. In this study, we meticulously extracted bixin from annatto seeds and meticulously developed composites incorporating zinc carbonate (bixin/ZnCO3) and kaolinite (bixin/kaolinite). UV-visible spectroscopy was used for characterization, and the extracted bixin showed absorption peaks at 429, 453, and 481 nm, which were very similar to standard peaks at 429, 457, and 487 nm. The two samples also had the same retention times (7.07 min) according to further liquid chromatography analysis. Sweat pores were easier to detect thanks to the effectiveness of the bixin/ZnCO3 and bixin/kaolinite composites in creating high contrast sebaceous and natural latent fingerprints. These results highlight the composites’ potential as novel and fascinating instruments for papilloscopy applications, which might also improve forensic investigations.

Digital light processing 3D printing of microfluidic devices targeting high-pressure liquid-phase separations.

This paper focuses on 3D printing using digital light processing (DLP) to create microchannel devices with inner diameters of100, 200, and 500 µm and cater flow-through applications within the realm of analytical chemistry, in particular high-pressure liquid chromatographic separations. Effects of layer thickness and exposure time on channel dimensions and surface roughness were systematically investigated. Utilizing a commercially accessible 3D printer and acrylate resin formulation, we fabricated 100-500 µm i.d. squared and circular channel designs minimizing average surface roughness (< 20%) by applying a 20-µm layer thickness and exposure times ranging from 1.1 to 0.7s. Pressure resistance was measured by encasing microdevices in an aluminum chip holder that integrated flat-bottom polyetheretherketon (PEEK)nanoports allowing to establish the micro-to-macro interface to the HPLC instrument. After thermal post-curing and finetuning the clamping force of the chip holder, a maximum pressure resistance of 650bar (1.5% RSD) was reached (n = 3). A polymer monolithic support structure was successfully synthesized in situ with the confines of a 500 µm i.d. 3D printed microchannel. A proof-of-concept of a reversed-phase chromatographic gradient separation of intact proteins is demonstrated using an aqueous-organic mobile-phase with isopropanol as organic modifier.

3D printing of high solid Al2O3 ceramics based on green and renewable photosensitive resin with low viscosity and low shrinkage

AbstractA low‐viscosity bio‐based carbamate acrylate was synthesized by the reaction of pentamethylene diisocyanate derived from pentanediamine with a low molecular weight acrylate hydroxyl ester. The carbamate acrylate was used in the 3D printing of ceramics, and a correlation between the solid content and viscosity of the ceramic slurry was observed. The ceramic slurry exhibits good stability and low shrinkage. The results indicate that the viscosity of the ceramic slurry was 2.11 Pa s with a solid content of 80 wt%, which makes it suitable for digital light processing printing. In addition, a new type of photoinitiator called (2,4,6‐trimethylbenzoyl)bis(p‐tolyl)phosphine oxide (TMO) has been applied, demonstrating excellent potential in ceramic slurry. According to its thermogravimetric curve, a debinding and sintering process was designed, and ultimately an Al2O3 device with a density of 94.49% was prepared.

Digital light 3D printing of artificial bone with star-shaped polycaprolactone-based polyurethane acrylate

Advanced medical materials and manufacturing technologies are highly in demand in artificial bones. Herein, a four-arm star-shaped polycaprolactone polyurethane acrylate (FPCLA) was designed and synthesized. The photosensitive character of FPCLA contributed to the rapid prototyping and personalized customization under digital light processing (DLP) 3D printing technology. The FPCLA was prepared by introducing unsaturated double bonds into polycaprolactone tetraethyl alcohol (PCLT). We characterized the physico-chemical properties of the material through FTIR, H-NMR, GPC, DSC and SEM. Cell behaviors on material were observed in vitro. In addition, we employed a DLP 3D printer to evaluate the feasibility of FPCLA to fabricate artificial bone model. The photocuring star polycaprolactone was confirmed in detail by detection method. SEM analyses demonstrated that FPCLA has good tenacity. The material can be used to fabricated artificial bone with a diameter of 3.02 mm at its narrowest by DLP 3D printing technology. The cell survival rates of CCK-8 and Live/Dead fluorescence staining experiments were both above 90%, which indicated safety and feasibility of such new-generation artificial bone made of synthetic polymers.

Cost and Benefit Analysis of Newly Installed Digital Printing Department by Using System Dynamics Modeling Technique

Cost and Benefit Analysis of Newly Installed Digital Printing Department by Using System Dynamics Modeling Technique

Microstrip resonators on polyethylene terephthalate substrates realized by direct-write technology

Printed Electronics (PE) technology has obtained considerable attention due to the simplification of the manufacturing process that can be fully additive. In addition, PE offers possibility to use low-cost, low-temperature substrates, such as polyethylene terephthalate (PET) foil, which could serve as an alternative to conventional high-frequency substrates, like Rogers. In this study, digital printing technology direct write, or so-called dispensing is used to print microstrip Rectangular-shaped resonators (RSRs) on a flexible PET foil and a semi-flexible Rogers 4003 substrate. Resonators are printed by a contact dispenser Nordson EFD Pro Plus 4L/A from a conductive silver-based DuPont PE 874 paste. The selected straight and bent RSRs have deep resonance frequencies at 2.50, and 1.90 GHz, with an amplitude of about −50 and −60 dB, respectively. The mentioned resonators are simulated and printed; then the results are compared with a good match. Resonators on Rogers shows a good match between simulation and realization. On a PET substrate, a 6% shift of transmission zero location is observed. To better understand some probable challenges during the manufacturing of high-frequency resonators, the structure of printed layers is characterized, and the manufacturing process itself is completely analyzed.

Digital Light Processing 4D Printing of Poloxamer Micelles for Facile Fabrication of Multifunctional Biocompatible Hydrogels as Tailored Wearable Sensors.

The lack of both digital light processing (DLP) compatible and biocompatible photopolymers, along with inappropriate material properties required for wearable sensor applications, substantially hinders the employment of DLP 3D printing in the fabrication of multifunctional hydrogels. Herein, we discovered and implemented a photoreactive poloxamer derivative, Pluronic F-127 diacrylate, which overcomes these limitations and is optimized to achieve DLP 3D printed micelle-based hydrogels with high structural complexity, resolution, and precision. In addition, the dehydrated hydrogels exhibit a shape-memory effect and are conformally attached to the geometry of the detection point after rehydration, which implies the 4D printing characteristic of the fabrication process and is beneficial for the storage and application of the device. The excellent cytocompatibility and in vivo biocompatibility further strengthen the potential application of the poloxamer micelle-based hydrogels as a platform for multifunctional wearable systems. After processing them with a lithium chloride (LiCl) solution, multifunctional conductive ionic hydrogels with antifreezing and antiswelling properties along with good transparency and water retention are easily prepared. As capacitive flexible sensors, the DLP 3D printed micelle-based hydrogel devices exhibit excellent sensitivity, cycling stability, and durability in detecting multimodal deformations. Moreover, the DLP 3D printed conductive hydrogels are successfully applied as real-time human motion and tactile sensors with satisfactory sensing performances even in a -20 °C low-temperature environment.

Rapid tooling for rubber extrusion molding by digital light processing 3D printing with dual curable vitrimers

AbstractFor the manufacture of extrusion dies, three‐dimensional (3D) printing with photopolymers offers numerous advantages including flexibility, high surface quality, decent build speed, low costs and a reduced amount of waste. However, the majority of photocurable resins used in vat photopolymerization 3D printing rely on acrylates, which entail 3D‐printed objects with poor mechanical properties. In particular, the high brittleness limits their application in rapid tooling, for which tough materials with high glass transition temperatures (Tg) are required. In the present study, we highlight the use of dual curable acrylate‐epoxy resins with dynamic covalent bonds for the direct fabrication of extrusion dies. During digital light processing (DLP) 3D printing the acrylate network is formed, whose toughness and thermal stability are significantly enhanced by the thermoactivated formation of a second network. By following a postbaking procedure, aminoglycidiyl monomers are cured with an anhydride hardener bearing bulky norbornene groups yielding interpenetrating polymer networks with a Tg &gt; 100°C. The tertiary amine groups present in the structure of the aminoglycidyl derivatives do not only accelerate the ring‐opening reaction but also act as internal catalysts and activate bond exchange reactions between free –OH groups and ester moieties available in the photopolymer. This is confirmed by rheometer studies showing a distinctive stress relaxation at elevated temperature and giving rise to a possible reprocessability of the 3D‐printed dies. With a selected resin formulation, a set of dies is printed by DLP 3D printing, with which a highly filled rubber compound is successfully extruded. The results clearly show that dual curable resins with dynamic covalent bonds are a promising class of material for rapid tooling and pave the way towards a customized and convenient fabrication of extrusion dies for rubber processing.

4D-Printed Elution-Peak-Guided Dual-Responsive Monolithic Packing for the Solid-Phase Extraction of Metal Ions.

Four-dimensional printing (4DP) technologies are revolutionizing the fabrication of stimuli-responsive devices. To advance the analytical performance of conventional solid-phase extraction (SPE) devices using 4DP technology, in this study, we employed N-isopropylacrylamide (NIPAM)-incorporated photocurable resins and digital light processing three-dimensional printing to fabricate an SPE column with a [H+]/temperature dual-responsive monolithic packing stacked as interlacing cuboids to extract Mn, Co, Ni, Cu, Zn, Cd, and Pb ions. When these metal ions were eluted using 0.5% HNO3 solution as the eluent at a temperature below the lower critical solution temperature of polyNIPAM, the monolithic packing swelled owing to its hydrophilic/hydrophobic transition and electrostatic repulsion among the protonated units of polyNIPAM. These effects resulted in smaller interstitial volumes among these interlacing cuboids and improvements in the elution peak profiles of the metal ions, which, in turn, demonstrated the reduced method detection limits (MDLs; range, 0.2-7.2 ng L-1) during analysis using inductively coupled plasma mass spectrometry. We studied the effects of optimizing the elution peak profiles of the metal ions on the analytical performance of this method and validated its reliability and applicability by analyzing the metal ions in reference materials (CASS-4, SLRS-5, 1643f, and Seronorm Trace Elements Urine L-2) and performing spike analyses of seawater, groundwater, river water, and human urine samples. Our results suggest that this 4D-printed elution-peak-guided dual-responsive monolithic packing enables lower MDLs when packed in an SPE column to facilitate the analyses of the metal ions in complex real samples.