Digital Printing Techniques Research Articles

REVIEW OF TEXTILE PRINTING: DIFFERENTIATION OF BLOCK, SCREEN & DIGITAL PRINTING

In India is well known for its traditional culture and art features. Hand block printing techniques are practiced in Rajasthan. Hence, the block printing is a slow process. Printing process of desired pattern is defined and repeated. The various styles for block printing are significant of the country in rich culture and heritage. It is a unique of each region will have a different variations of traditional craft. That was crafted for propagating Hindus mythology of depicted folk style story transform of imagination forms of God and goddess in literature. In this article, we will discuss about block printing, the development digital printing and manual of screen printing. The comparison of these three styles of textiles printing. It is a oldest method of art craft. The economics of ink jet printing are the main driver of digital printing technique. The costs of ink jet printing are lower for short run lengths than in traditional screen printing. This switches for longer runs production. Short-run textile printing commissions are the main source of jobs for small to medium scale textile producers in Ghana. And manual screen printing is the main process employed by these small-scale textile printers. These layers of limitations negatively affect the overall outcome of the prints. This is because, the large-scale textile factories in Ghana can print a minimum of 2400 yards due to their machine settings, calibration and running cost to make the least returns. KEYWORDS: Hand block printing, natural dyes, screen printing, techniques, digital printing.

Method for controlling the polypropylene wettability using surfactants

This paper describes a novel approach to imaging polypropylene PP using digital inkjet printing techniques. The low surface energy of PP, and significant hydrophobic properties prevent it from being used for direct coloration by available methods. A number of surfactants (surfactants) have been proposed as pre-coatings to improve the adhesion between the polymer surface and the ink. Due to the amphiphilicity of surfactants, improved coloration and enhanced color rendering are provided. The polymer/surfactants interactions were evaluated by IR spectroscopy. The amount of surfactants was evaluated using TGA analysis. The effect of modifying agent concentration was evaluated using wetting edge angle measurement. The surface morphology was evaluated using scanning electron microscopy. The test scales were printed and their colorimetric performance was investigated. The study demonstrates the high potential of surfactants for tuning the properties of nonwoven polymeric materials.

(Invited) Solution-Processable Materials and Structuring Processes for Electrochemically Gated Thin Film Devices

Printed and flexible electronics enable interesting novel applications in the fields of sensors [1], bioelectronics [2], and security applications [3]. Most of them gain their functionality from a layered structure composed of different materials that interact with each other. For semiconducting layers, organic and inorganic materials can be used; in this regard, the respective functional materials need to be formulated into inks that are then printed on various substrates. The structuring process of printing is a complex process in which many chemical and physical process parameters need to be controlled at the same time, such as drop volume, the waveform of the electrical signal controlling droplet formation, or the drying time. Also, the surface of the substrate plays a decisive role in printing accuracy and layer morphology. After printing, post-treatments are often necessary to obtain the desired features, since the properties of bulk materials often differ from printed nanoparticulate or precursor-derived films. For instance, temperature sintering of printed layers can improve conductivities as well as UV-curing which also allows sintering at lower temperatures.As functional materials for thin-film transistors and other devices, in particular inorganic materials such as metal oxide precursor and nanoparticulate inks are used. These can show advantages of high carrier mobilities, transparency, stability in air, non-toxicity, and can be prepared mostly by using water or alcohol-based solvents. We employ a large portfolio of various printing techniques, including inkjet, gravure, screen, and even direct laser printing. Nevertheless, for all of these techniques, printing thin pinhole-free dielectrics is a challenge and crucial for the whole device functionality, since pinholes can lead to short circuits or other defects of the device. Especially for transistors, this is a fundamental problem, since very thin dielectric layers are needed between the top gate and the semiconducting channel.To circumvent this problem, we have developed in the past years a composite solid polymer electrolyte (CSPE) consisting of two solutions, namely LiClO4+PC and PVA+DMSO. This approach allows employing a different geometry of the transistors and a thicker electrolyte layer while keeping the functionality. The electrolyte ink is inkjet-printable and dries at room temperature. The advantage of such electrolytes is their ability to cover well even rough film surfaces and create a large Helmholtz double layer capacitance, which causes low threshold voltages and hence allows for low-voltage operation of the printed devices. We have further expanded the electrolyte to chemically cross-linked ion gels that even show better device reliability concerning the humidity of the environment at similar electrical performance. Our recent works on device and component levels include ultra-low-power latches operating down to 0.6 V, pn- and Schottky-diodes, resistors, and logic gate standard cells such as inverter, NAND, and NOR-gates, as well as circuits such as ring oscillators, rectifiers, and security primitives [1].This presentation starts by introducing various semiconducting inks based on either nanoparticles or precursor solutions and discusses thin film properties, microstructure, and finally the step-by-step device fabrication processes. We employ several structuring processes along the process chain, including laser ablation and lift-off, digital printing techniques such as inkjet, superinkjet, and direct laser printing. In addition, doping concepts to tune the threshold voltage and composite solid polymer electrolytes that are compliant with silver electrodes will be presented. The talk will further discuss a plethora of realized devices, including transistors, memristors, and even fully integrated circuits. In more detail, the fabrication and electrical performance of inkjet and laser-printed ZnO digital memristors as well as WOx analog memristors which show “learning” behavior will be discussed [4]. The conductance of analog-type devices can be gradually manipulated to emulate different behaviors of the biological synapse, such as short-time plasticity, long-term potentiation, and long-term depression.In addition, progress towards transistor architectures using nanoparticle-passed InO as the semiconductor and Pt or ITO as electrode materials is shown. Along these lines, transistors with InO-semiconducting nanoparticles printed into a 3D laser-written polymer reservoir with a 10 µm height are presented and their electrical characteristics discussed. Our devices show high ion currents in the range of ~mA for typical widths of a few hundreds of micrometers. These 3D hybrid devices have a huge potential for biohybrid systems, in which the reservoir structure can be used to accommodate biological material or tissue, or even single cells.[1] Marques et. al., Advanced Materials 31, (2019), https://doi.org/10.1002/adma.201806483.[2] Saghafi et. al., Adv. Funct. Mat., Early View, (2023), https://doi.org/10.1002/adfm.202308613[3] Zimmermann et. al., IEEE Transactions on VLSI Systems 27 (2019), https://doi.org/10.1109/TVLSI.2019.2924081[4] Hu et. al., Adv. Funct. Mat., EarlyView (2023), https://doi.org/10.1002/adfm.202302290

Developing poplar wood into a green structure-decoration integrated material for prefabricated wooden building application

Fast growing poplar wood poses significant challenges including low mechanical strength, poor dimensional stability and weak texture, limiting its direct application in the field of building structures and decoration. We treated poplar wood using compression, digital printing and waterproofing techniques to develop a green structure-decoration integrated material. The compression treatment significantly improved the wood density, fiber orientation and surface smoothness. At a compression ratio of 60 %, poplar veneer demonstrates remarkable improvements in modulus of elasticity (MOE), modulus of rupture (MOR) and surface smoothness, with increases of 222.53 %, 233.53 % and 93.20 %, respectively, compared to uncompressed wood. Notably, this compression treatment reduces the surface roughness of poplar to 0.75 μm, meeting the flatness requirements for digital printing. Consequently, clear textures and vibrant colors are directly printed onto the flat surface of compression-densified poplar wood, eliminating the need for traditional surface sanding pre-treatment process, and accordingly improving the efficiency of the material preparation. Furthermore, a final waterproofing emulsion spraying treatment creates a dense micro/nanoscale hierarchical structure on the surface, enabling the compression-densified poplar wood samples to achieve MOE and MOR of 14.15 GPa and 123.00 MPa respectively, even after water absorption and re-dried processes. These values consistently exceed the standard value of MOE (12.50 GPa) and MOR (35.00 MPa) for the highest grade (TCT40) specified in GB50005-2017, indicating significantly improved structural stability. The structure-decoration integrated materials developed in this study offer high strength and dimensional stability, making them promising candidates for high value utilization in prefabricated wooden buildings.

Improving Definition of Screen-Printed Functional Materials for Sensing Application.

Screen printing is one of the most used techniques for developing printed electronics. It stands out for its simplicity, scalability, and effectivity. Specifically, the manufacturing of hybrid integrated circuits has promoted the development of the technique, and the photovoltaic industry has enhanced the printing process by developing high-performance metallization pastes and high-end screens. In recent years, fine lines of 50 μm or smaller are about to be adopted in mass production, and screen printing has to compete with digital printing techniques such as inkjet printing, which can reach narrower lines. In this sense, this work is focused on testing the printing resolution of a high-performance stainless-steel screen with commercial conductive inks and functional lab-made inks based on reduced graphene oxide using an interdigitated structure. We achieved electrically conductive functional patterns with a minimum printing resolution of 40 μm for all inks.

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.

Inkjet-printed high-performance and mechanically flexible organic photodiodes for optical wireless communication

Emerging areas such as the Internet of Things (IoT), wearable and wireless sensor networks require the implementation of optoelectronic devices that are cost-efficient, high-performing and capable of conforming to different surfaces. Organic semiconductors and their deposition via digital printing techniques have opened up new possibilities for optical devices that are particularly suitable for these innovative fields of application. In this work, we present the fabrication and characterization of high-performance organic photodiodes (OPDs) and their use as an optical receiver in an indoor visible light communication (VLC) system. We investigate and compare different device architectures including spin-coated, partially-printed, and fully-printed OPDs. The presented devices exhibited state-of-the-art performance and reached faster detection speeds than any other OPD previously reported as organic receivers in VLC systems. Finally, our results demonstrate that the high-performance of the fabricated OPDs can be maintained in the VLC system even after the fabrication method is transferred to a fully-inkjet-printed process deposited on a mechanically flexible substrate. A comparison between rigid and flexible samples shows absolute differences of only 0.2 b s−1 Hz−1 and 2.9 Mb s−1 for the spectral efficiency and the data rate, respectively.

Analysis of Design Concepts: A Comparative Study of Pre- And Post- 2000 Printed Fabrics of Textile Printing Companies in Ghana

Purpose: The paper aims to analyze and compare the design concepts in printed fabrics between the pre- and post-2000 periods in Ghana. By examining the changes in design trends, techniques, and motifs, the study also aims to identify the factors that have influenced the evolution of printed fabric designs over time. Methods: This research adopts a concurrent embedded mixed method design, combining qualitative and quantitative methods. Primary data is collected through interviews with textile designers, manufacturers, and industry experts. A comprehensive analysis of printed fabric samples from pre- and post-2000 periods is conducted. The data collected is then analyzed using thematic analysis and statistical techniques. Findings: This research provides insights into the changes in design concepts in the printed fabric industry in Ghana. The study reveals shifts in design trends, such as the adoption of digital printing techniques, the incorporation of contemporary motifs, and the influence of global fashion trends. Research Limitation/Implications: The study's limitations include small sample size, limited representation of Ghana's textile printing industry's diverse design concepts, and insufficient exploration of production processes or market dynamics. Practical Implication: Research highlights design changes in Ghanaian textiles, enabling designers to create innovative, marketable printed fabrics and manufacturers to adapt production processes. Social Implication: The textile printing industry in Ghana significantly impacts cultural identity and economic development. Originality/Value: This research adds value to the existing literature on the textile printing industry by comprehensively analysing the design concepts in printed fabrics in Ghana.

Low-cost ceramic membranes manufacture using INKJET technology for active layer deposition and validation on membrane bioreactors

The fabrication of eco-friendly ceramic membranes based on low-cost raw materials, using digital INKJET printing techniques for active layer deposition and its validation in a membrane bioreactor (MBR) has been studied. The raw materials used in the manufacture of the support layer were UA50/2 clay, chamotte, calcium carbonate and potato starch. A MBR laboratory plant was operated to treat municipal wastewater with three ceramic membranes with different grammages in the selective layer deposition. The membrane performance at laboratory scale was evaluated in terms of transmembrane pressure (TMP) evolution for a constant permeate flux, permeate quality and mixed liquor characteristics. From these experiments, it was selected the membrane which obtained the lowest TMP profile maintaining appropriate water quality parameters (chemical oxygen demand (COD) removal percentage around 90% and turbidity around 0.06 NTU). This membrane was also operated at pilot plant scale in order to validate it at higher scale. Results indicated that TMP values were in the range of 0.06 and 0.1 bar, COD removal percentage was around 98% and microbiology analysis demonstrated that the quality of the effluent, according to European regulation 2020/741, can be classified as Class A and it can be reused for non-potable purposes.

Plasmon-enhanced photodetectors fabricated using digital inkjet-printing on chemically nanopatterned silicon wafers

In this study, we have fabricated and characterized three different configurations of photodetectors with digital inkjet printing techniques on different types of silicon substrates, such as pristine n-type silicon and chemically nanostructured n-type silicon, with and without Ag nanoparticle-induced surface-plasmon enhancement. Among these three comparison batches, digitally printed devices on chemically nanostructured n-type silicon with Ag nanoparticle-induced enhancement yield the highest photocurrent enhancement factor of 920×, the lowest rise and decay times of τr = 176 ms and τd = 98 ms, respectively, and the highest responsivity of 24.8 mA W−1 at wavelengths ranging from 380 to 700 nm. Most importantly, we demonstrate that these devices are highly stable after fabrication, losing less than 3% of their efficiency over 60 days under ambient conditions. We firmly believe that this simple device architecture and effective digital fabrication process are most promising for the realization of efficient, stable, and low-cost photodetectors fabricated at large scales.

Monolithically printed all-organic flexible photosensor active matrix

Upcoming technologies in the fields of flexible electronics require the cost-efficient fabrication of complex circuitry in a streamlined process. Digital printing techniques such as inkjet printing can enable such applications thanks to their inherent freedom of design permitting the mask-free deposition of multilayer optoelectronic devices without the need for subtracting techniques. Here we present an active matrix sensor array comprised of 100 inkjet-printed organic thin film transistors (OTFTs) and organic photodiodes (OPDs) monolithically integrated onto the same ultrathin substrate. Both the OTFTs and OPDs exhibited high-fabrication yield and state-of-the-art performance after the integration process. By scaling of the OPDs, we achieved integrated pixels with power consumptions down to 50 nW at one of the highest sensitivities reported to date for an all-organic integrated sensor. Finally, we demonstrated the application potential of the active matrix by static and dynamic spatial sensing of optical signals.

Utilization of Laboratory Papers with Non-Wood Fibres as Printing Substrates Observed Through the Maximum Ink Penetration Depth

The use of non-wood fibres for paper production could be one of the most environmentally friendly and economical alternatives. Reducing the consumption of wood pulp in paper and cardboard production by replacing wood pulp with alternative plant biomass could be a viable solution, as the amount of non-wood fibres in biomass is far from being exhausted. In this study, straw from the most commonly grown agricultural crops in Croatia was used as a source of non-wood fibres. Agricultural residues from wheat, barley and triticale were selected as a substitute for wood fibres for the production of laboratory papers with straw fibres. Under laboratory conditions, straw pulp was mixed with recycled wood pulp in a ratio of 30:70 to produce paper sheets that can be printed with different printing techniques. Regardless of the printing technique used, it is desirable that the prints contain a high-quality reproduction of the image and text on the surface of the paper and that the ink does not penetrate completely through the substrate. In this context, this study observed the use of laboratory-made papers with non-wood fibres as the printing substrate by analysing the maximum depth of ink penetration into the printing substrate obtained with two printing techniques - a modern one (digital UV inkjet) and a very high quality conventional one (gravure). It was found that the gravure printing favoured a greater penetration of the UV ink into the substrate with the addition of straw pulp compared to the digital printing technique. However, this is a consequence of the printing technique, as similar ink penetration was also observed on the laboratory substrate made only from recycled fibres. Compared to commercial papers, the ink penetration is slightly higher into the laboratory made printing substrates. It is interesting to note that the printing substrate with the addition of 30% triticale pulp has the lowest ink penetration, especially in multicolour prints produced with the digital UV inkjet printing technique.

Upcycling Fabric Waste for Home Decoration by Implementing Islamic Art Approach

Humanity's activities cause the destruction that occurs in the world as a caliphate, as stated in Surah Ar-Rum (30), verse 41 of the Quran. One of the products that might harm the ecosystem is waste. Various countries, including the Indonesian Government, have competed with numerous initiatives and policies to save environmental sustainability. The author of this study provided training on how to conserve the environment by processing trash, particularly fabric waste. Bina Nusantara University's community development initiative invites numerous assisted MSMEs to participate in a waste management training session. Participants are instructed on how to transform fabric waste into useful interior products. The techniques conducted start from joining fabric waste with patchwork, quilting, and applique connection techniques. From the connection results, the product's value can be increased again by adding a digital screen printing technique. Islamic Art is one of the many motifs that can be used. Implementing Islamic geometric patterns and floral, vegetal, and calligraphy designs on interior accessories are some examples of Islamic art motifs. Apart from being able to decorate the interior of the home, particularly by giving it an Islamic feel, the objective of creating this product is to conserve the environment through upcycling technology.

Project-Based Learning Through Digital Printing Techniques To Improve Students' Local Cultural Innovation Creativity

Aligning the needs of students, vocational schools and the world of work, many of whom have failed due to low mastery of soft skills. The purpose of this study, to describe the Project-Based Learning (PjBL) model in the manufacture of batik products with the motif of the peacock ngibing batik on the local cultural heritage of Tasikmalaya, and Secondary Vocational Education (SMK). In this study, the author will design a motif inspired by the ngibing peacock motif combined with Tasikmalaya batik for adult women with digital printing techniques so that the younger generation is more familiar with and interested in Tasikmalaya batik. The making of this motif will then be made into sheets of primissima cotton cloth that can be used to meet the fashion needs of the target market. This study uses a mix method with a quasi-experimental approach, as well as data collection techniques using questionnaires, observations, in-depth interviews and documentation. The results of this research study illustrate that the inheritance of local culture in SMK uses the PJBL model in passing down creativity and innovation of crafts and batik/textile creations from generation to generation. The Tasikmalaya batik pattern has its own charm as well as a beautiful and beautiful character with a combination of bright colors and patterns derived from flora and fauna. The philosophical value contained in this batik is that the peacock symbolizes the beauty of nature with its various flora and fauna. Ngibing symbolizes the customs and culture of a harmonious and peaceful society. Through the combination of Tasikmalaya batik with street style, it is hoped that it will produce innovative works and convey the meaning of the philosophy contained in it. The added value of this design is that it maintains the work of Indonesian art which makes attractive fashion designs with contemporary styles that have more value in the eyes of the world.

3D printed long-term structurally stable bioceramic dome scaffolds with controllable biodegradation favorable for guided bone regeneration

Alveolar bone loss and insufficient bone mass are major obstacles to the oral implant treatment. Guided bone regeneration (GBR) is an effective and widely used method to solve this problem. Titanium mesh with good 3D space maintenance ability shows excellent effect in the assistance of GBR. Unfortunately, such metal mesh needs to be removed by secondary operation, and the exposure after operation can’t be completely avoided. Thus, it is a big challenge to repair the alveolar bone defects with different shapes and sizes by customization. Herein, the wollastonite bioceramics without and with 6% magnesium doping (CSi, CSi-Mg6) were prepared to fabricate the macroporous dome-like meshes with different CSi/CSi-Mg6 mass ratio (0:100, 16:84, 32:68) via digital light processing-based 3D printing (DLP) technique. The mechanical parameters, biodegradable rate and osteogenic stem cell viability in vitro of the bioceramic scaffolds with different morphologies were also evaluated systematically. The macroporous bioceramic dome- or titanium mesh-assisted osteogenic potentials in the calcined bone granules were evaluated in the rabbit calvarial bone defect models. The experimental results showed that the scaffolds with 16%CSi exhibited satisfactory mechanical properties and promoted the proliferation and differentiation of osteogenic stem cells. The bioactive domes displayed significantly higher osteostimulate activity than the metal mesh in the calcined bone mineral granule systems. The appreciable CSi-Mg6 content (≥84%) in the dome scaffolds could maintain the porous structures after 16 weeks of implantation, and especially the presence of 16% CSi in the bioceramic dome may greatly balance the scaffold biodegradation and restoration treatment. Totally, the 3D printed nonstoichiometric wollastonite-based scaffolds are expected to be the promising candidates to replace titanium mesh in GBR.

Indium Tin Oxide-Free Inverted Organic Photovoltaics Using Laser-Induced Forward Transfer Silver Nanoparticle Embedded Metal Grids.

Laser-induced forward transfer (LIFT) printing has emerged as a valid digital printing technique capable of transferring and printing a wide range of electronic materials. In this paper, we present for the first time LIFT printing as a method to fabricate silver (Ag) nanoparticle (np) grids for the development of indium tin oxide (ITO)-free inverted PM6:Y6 nonfullerene acceptor organic photovoltaics (OPVs). Limitations of the direct use of LIFT-printed Ag np grids in inverted ITO-free OPVs are addressed through a Ag grid embedding process. The embedded laser-printed Ag grid lines have high electrical conductivity, while the Ag metal grid transparency is varied by altering the number of Ag grid lines within the inverted OPVs’ ITO-free bottom electrode. Following the presented Ag-grid embedding (EMP) process, metal-grid design optimizations, and device engineering methods incorporating an EMB-nine-line Ag np grid/PH500/AI4083/ZnO bottom electrode, we have demonstrated inverted ITO-free OPVs incorporating laser-printed Ag grids with 11.0% power conversion efficiency.

Influence of Ink Curing in UV LED Inkjet Printing on Colour Differences, Ink Bleeding and Abrasion Resistance of Prints on Textile

Digital printing techniques are increasingly present in the field of textile printing. Particularly prominent is the inkjet printing technique using water-based inks, UV LED inkjet printing also increasingly being in use. UV LED inkjet is primarily not intended for direct clothing printing; however, it can be used especially as a hybrid solution in the soft signage market. It is a great option for the printers that are not engaged only in textile printing, and want a more versatile print portfolio, extending it to non-clothing textile products, e.g. soft signage and non-wearable products. As these types of products often require colour reproduction of logos, accurate colour reproduction, good ink adhesion and sharpness are important just like in other printing technologies. In order to evaluate the impact of UV LED radiation amount on colour differences, ink bleeding and abrasion resistance, six different fabric samples (five woven and one nonwoven) were printed using a UV LED inkjet printer. Based on the results of colour difference, it was established that a reduction of UV radiation (by half the manufacturer’s recommended amount) had no effect on this parameter. However, perceptible colour differences were observed with the use of different M measurement conditions defined by the international standard ISO 13655-2017. Reducing the amount of UV radiation had no effect on the adhesion and durability of the printed ink. Small differences detected in these two parameters were mainly a consequence of the properties of textile materials and not of decreased UV radiation.

3D-Printed Biodigital Clay Bricks.

Construction materials and techniques have witnessed major advancements due to the application of digital tools in the design and fabrication processes, leading to a wide array of possibilities, especially in additive digital manufacturing tools and 3D printing techniques, scales, and materials. However, possibilities carry responsibilities with them and raise the question of the sustainability of 3D printing applications in the built environment in terms of material consumption and construction processes: how should one use digital design and 3D printing to achieve minimum material use, minimum production processes, and optimized application in the built environment? In this work, we propose an optimized formal design of “Biodigital Barcelona Clay Bricks” to achieve sustainability in the use of materials. These were achieved by using a bottom-up methodology of biolearning to extract the formal grammar of the bricks that is suitable for their various applications in the built environment as building units, thereby realizing the concept of formal physiology, as well as employing the concept of fractality or pixilation by using 3D printing to create the bricks as building units on an architectural scale. This enables the adoption of this method as an alternative construction procedure instead of conventional clay brick and full-scale 3D printing of architecture on a wider and more democratic scale, avoiding the high costs of 3D printing machines and lengthy processes of the one-step, 3D-printed, full-scale architecture, while also guaranteeing minimum material consumption and maximum forma–function coherency. The “Biodigital Barcelona Clay Bricks” were developed using Rhinoceros 3D and Grasshopper 3D + Plugins (Anemone and Kangaroo) and were 3D printed in clay.

Three-Dimensional Auricular Subunit Models for Cartilage Framework Fabrication: Our Preliminary Experience.

Three-dimensional (3D) digital imaging and printing techniques have been popularly applied in microtia reconstruction. However, there is a lack of clinical report of using them to create 3D printed ear subunit models for cartilage framework fabrication. A retrospective study of patients who underwent auricle reconstruction with 3D templates was performed. Patients' demography, surgical complications, framework accuracy, and aesthetic outcomes of the reconstructed auricles were analyzed. Twenty cases included in this study. Complications were minor. The average (median) assessing scores for the framework quality and the reconstructed auricle aesthetics were 8.50 (8) and 8.30 (8), respectively. Our study found that the use of custom-printed tridimensional ear subunit models achieved a relatively high framework precision and gained good outcomes of the reconstructed ears.Level of Evidence: Level IV.