Investigation of the effect of light fastness on the color changes of maps prepared by electrophotographic digital printing

In this study the prints were made on paper substrates, which were thought as map substrate alternatives, with 3 different surface properties at 1200 dpi by using the electrophotographic printing system. Color and gloss values of the samples were determined both before and after exposure to light for a period of 42 hours to determine the light fastness of the substrate and the print on it. The studies revealed that after the light fastness tests (i) the width of the color universe of the papers with matte surfaces is more than that of the papers with glossy surfaces, (ii) the loss of brightness of woodfree paper is higher than that of the other paper samples and (iii) the print chroma values obtained in woodfree paper is lower than those of the coated surfaces. Moreover, (iv) the delta E 00 {E_{00}} measurements revealed that all paper samples experienced different color losses in different colors, and the most significant differences in these color losses were in magenta and black.

Robotic Spatial Printing For Designers

<p>This research developed a fully-integrated robotic printing system, using new methods of additive manufacture (AM) that enables users to explore spatially printed structures with increased freedom of geometric complexity. Current AM technologies, such as Fusion Deposition Modelling (FDM), can rapidly translate design ideations into solid forms by precisely depositing consecutive layers of material in coordination with the movements of a robotic platform. Using this method, solid objects are digitally deconstructed into linear toolpaths and physically reconstituted with thermoplastic extrusion equipment; the toolpath becomes the form. Spatial printing, using methods such as those demonstrated in this research, offers a new way of building 3D forms. By harnessing the potential of FDM equipment and materials for generating self-supporting structures, the user can create complex free-standing structures unshackled from the layered constraints of typical additive manufacturing processes. Here, the user acts as an informed negotiator between digital form and physical manifestation where movement realises form. A complete spatial printing system was built that harnesses the complexity of robotic movements and responds to the needs of printing materials through a feedback loop that draws from the results of experimentation. Bespoke printing equipment and computational processes strive to improve the craft qualities and printability of input materials with a specific focus on compatibility with co-extrusion biopolymer filaments developed by Scion. This thesis illustrates the development of a versatile spatial printing system and subsequent investigations into the craft qualities and freedom of complexity that this system offers to designers and architects.</p>

Robotic Spatial Printing For Designers

<p>This research developed a fully-integrated robotic printing system, using new methods of additive manufacture (AM) that enables users to explore spatially printed structures with increased freedom of geometric complexity. Current AM technologies, such as Fusion Deposition Modelling (FDM), can rapidly translate design ideations into solid forms by precisely depositing consecutive layers of material in coordination with the movements of a robotic platform. Using this method, solid objects are digitally deconstructed into linear toolpaths and physically reconstituted with thermoplastic extrusion equipment; the toolpath becomes the form. Spatial printing, using methods such as those demonstrated in this research, offers a new way of building 3D forms. By harnessing the potential of FDM equipment and materials for generating self-supporting structures, the user can create complex free-standing structures unshackled from the layered constraints of typical additive manufacturing processes. Here, the user acts as an informed negotiator between digital form and physical manifestation where movement realises form. A complete spatial printing system was built that harnesses the complexity of robotic movements and responds to the needs of printing materials through a feedback loop that draws from the results of experimentation. Bespoke printing equipment and computational processes strive to improve the craft qualities and printability of input materials with a specific focus on compatibility with co-extrusion biopolymer filaments developed by Scion. This thesis illustrates the development of a versatile spatial printing system and subsequent investigations into the craft qualities and freedom of complexity that this system offers to designers and architects.</p>

Design and Implementation of 3D Printing Using a Universal Printing System on the Robot Arm UR5

The combination of two rapidly evolving technologies such as additive manufacturing technology and robotics opens up a wide potential for solving new production tasks. In advance, several challenges need to be addressed in order to intensify the possibilities for developing the combination of these technologies. The aim of the article is to point out the possibility of designing a simple universal printing system for the collaborative robot UR5 with an orientation on the need to implement 3D printing. The solution proposed in this way makes it possible to simplify the design of the movements to reduce any further structural modifications and also to reduce the potential mechanical deficiencies of the structure of the printing device.

Color printing on pre-colored textiles

Managing color on a particular imaging system is a wellunderstood challenge with a wealth of existing models, methods and techniques. In the case of printing systems, these tend to operate in the context of a single substrate, where managing color on every additional substrate is approach as a separate, detached problem. While such a mind-set works reasonably well in general, it breaks down when it comes to printing onto precolored textiles, such as pre-dyed fabrics. The present paper therefore introduces a family of approaches that support the use of multiple pre-colored textiles on a given printing system that also allow for a balance between characterization effort and color match accuracy. This, in turn provides solutions that can fit a variety of practical working patterns to maximize overall efficiency and performance.

Development of a highly controlled system for large-area, directional printing of quasi-1D nanomaterials

Printing is a promising method for the large-scale, high-throughput, and low-cost fabrication of electronics. Specifically, the contact printing approach shows great potential for realizing high-performance electronics with aligned quasi-1D materials. Despite being known for more than a decade, reports on a precisely controlled system to carry out contact printing are rare and printed nanowires (NWs) suffer from issues such as location-to-location and batch-to-batch variations. To address this problem, we present here a novel design for a tailor-made contact printing system with highly accurate control of printing parameters (applied force: 0–6 N ± 0.3%, sliding velocity: 0–200 mm/s, sliding distance: 0–100 mm) to enable the uniform printing of nanowires (NWs) aligned along 93% of the large printed area (1 cm2). The system employs self-leveling platforms to achieve optimal alignment between substrates, whereas the fully automated process minimizes human-induced variation. The printing dynamics of the developed system are explored on both rigid and flexible substrates. The uniformity in printing is carefully examined by a series of scanning electron microscopy (SEM) images and by fabricating a 5 × 5 array of NW-based photodetectors. This work will pave the way for the future realization of highly uniform, large-area electronics based on printed NWs.

Customisable Tablet Printing: The Development of Multimaterial Hot Melt Inkjet 3D Printing to Produce Complex and Personalised Dosage Forms

One of the most striking characteristics of 3D printing is its capability to produce multi-material objects with complex geometry. In pharmaceutics this translates to the possibility of dosage forms with multi-drug loading, tailored dosing and release. We have developed a novel dual material hot-melt inkjet 3D printing system which allows for precisely controlled multi-material solvent free inkjet printing. This reduces the need for time-consuming exchanges of printable inks and expensive post processing steps. With this printer, we show the potential for design of printed dosage forms for tailored drug release, including single and multi-material complex 3D patterns with defined localised drug loading where a drug-free ink is used as a release-retarding barrier. For this, we used Compritol HD5 ATO (matrix material) and Fenofibrate (model drug) to prepare both drug-free and drug-loaded inks with drug concentrations varying between 5% and 30% (w/w). The printed constructs demonstrated the required physical properties and displayed immediate, extended, delayed and pulsatile drug release depending on drug localisation inside of the printed formulations. For the first time, this paper demonstrates that a commonly used pharmaceutical lipid, Compritol HD5 ATO, can be printed via hot-melt inkjet printing as single ink material, or in combination with a drug, without the need for additional solvents. Concurrently, this paper demonstrates the capabilities of dual material hot-melt inkjet 3D printing system to produce multi-material personalised solid dosage forms.

Development of an in-situ printing system with human platelet lysate based bioink to treat corneal perforation

Purpose: Corneal perforation is a clinical emergency. Tissue glue to seal the perforation, and supplementary topical medication represents existing standard treatment. Previously, our group developed a transparent bioink that showed good cell compatibility and accelerated corneal epithelial cells healing in-vitro. This study aims to develop a novel treatment method for corneal perforation using this bioink. Methods: Rheometry was used to measure bioink behaviour at room and corneal surface temperatures. Bioink adhesiveness to porcine skin and burst pressure limit were also measured. Based on rheological behaviour, a hand-held biopen was developed to extrude the bioink onto the cornea. An animal trial (5 New Zealand white rabbits) to compare bioink and cyanoacrylate glue (control group) impact on a 2mm perforation was conducted to evaluate safety and efficacy. Results: Bioink has higher adhesiveness compared to commercial fibrin glue and can withstand burst pressure approximately 6.4x higher than routine intraocular pressure. Bioink-treated rabbits had lower pain score and faster recovery, despite generating similar scar-forming structure after healing compared to controls. No secondary corneal ulcer was generated in rabbits treated with bioink. Conclusions: This study reports a novel in-situ printing system capable of delivering a transparent bioink to the cornea and successfully treating small corneal perforations. Bioink-treated rabbits recovered faster to completely healed perforation and required no additional analgesia. Both groups showed scarred corneal tissue after healing, however no infection and inflammation was observed 3 weeks. The delivery system was easy to use and may represent an alternative treatment for corneal perforation.