Inkjet-based 3D bioprinting

In recent years, ink jet has emerged as one of the mainstream printing technologies. Since its market inception in 1985, Hewlett-Packard's thermal ink jet technology (TIJ) has evolved progressively from a 12 nozzle 96 dpi print head to a 300 nozzle 600 dpi print head. TIJ has made rapid progress enabling it to print text output on plain paper that challenges laser printers, and realistic photographic images that rival silver halide, at a low consumer price. Thermal ink jet technology continues to enjoy a greater unit market share than any other digital printing technology and all other ink jet technologies combined. The driving forces for the advancement of TIJ have been better, faster, and cheaper printers for consumers. These goals involve key attributes such as ink performance (gamut, sharpness, fastness), minimum deliverable colorant (drop volume), rate of colorant delivery (firing frequency, nozzle integration, firing chamber volume), and print engine cost per unit throughput. In this paper, key technology challenges for TIJ will be outlined. New materials and new processes that are required for the advancement of thermal ink jet printing are discussed. Recently, competing ink jet methods have (re-)emerged, notably piezoelectric ink jet. References will be made to piezoelectric ink jet when appropriate.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Personalisation of warfarin therapy using thermal ink-jet printing

Interactions of ink colourants with chemically modified paper surfaces concerning inkjet print improvement

Thermal inkjet printing of thin-film electrolytes and buffering layers for solid oxide fuel cells with improved performance

An amperometric glucose biosensor prototype fabricated by thermal inkjet printing

In recent years, inkjet digital printing technology has become a popular research area. This paper focuses on the spreading behavior of single ink drops on coated paper in digital inkjet printing. It explores the impact of ink drop spreading on monochromatic spectral reflectance, providing new insights for the theoretical development of spectral prediction models. The study involves constructing a spreading behavior model through theoretical modeling. Numerical simulations were conducted using the Volume of Fluid (VOF) method in Fluent software to assess the feasibility of the theoretical model. Finally, experimental fitting was used to validate the accuracy of the theoretical model. Considering the feathering effect in practical printing, a comprehensive monochromatic extended Clapper-Yule spectral prediction model was developed based on the spreading behavior of single ink drops. The prediction results of this model showed significant accuracy improvements in monochromatic spectral prediction compared to the traditional segmented Clapper-Yule model. This research offers new perspectives for spectral prediction and provides theoretical guidance for enhancing print image quality.

The development of new technology for the realisation of biocompatible and bioactive structures is an emerging field in the field of tissue engineering, regenerative medicine and biosensors. These techniques are generally based on the computer-aided design approach. Recently the use of ink-jet printers has been extensively studied both using bio-molecules and cells. Ink-jet systems were noted to cause cell damage in the microfluidic system and in the drop generation system (e.g. heating or piezoelectric), and different thermal inkjet printer heads have been used to address these points. In this work we underline that the impact of the drop on the substrate is more relevant, and show how the properties of the deposition surface can influence cell viability. Firstly the printing process and the drop impact were modelled using fluid-dynamics and fluid-structure interaction equations. To validate the model, the Olivetti BioJet system was used to print cells onto different substrates with different elastic and viscous properties and cell viability was monitored in time.

Drop-on-demand (DoD) ink-jet printing is an efficient technology for depositing picoliter drops on various printing surfaces. DoD technology is compatible with various liquids and does not require contacting the printing media. DoD inkjet printing combines several advantages including high speed, quiet operation, and compatibility with a variety of printing surfaces. Moreover, DoD printing can make patterns without any additional lithographic process. Ink-jet printing can reduce the number of processing steps compared to conventional patterning processes, which results in a lower production cost. Therefore, DoD ink-jet technology is applied in many engineering and scientific applications (see Figure 1), such as the formation of the conductive tracks for printed circuit boards, color filters in flat panel displays and plasma displays, polymer light-emitting diode displays, organic transistors, and the construction of DNA microarrays [1]-[5].

Bio-printing is a trending technology in the field of tissue engineering and regenerative medicine, creating complex three-dimensional structures. The advancements in bio-printing, including the steps and materials used in bio-printers, have been highlighted. Various bio-printing techniques such as micro-extrusion, inkjet printing, and laser-based approaches are discussed. Moreover, the roles of biomaterials and their importance in bio-printing cannot be overstated. Characteristics such as cell viability, adhesion, differentiation, biodegradability, and biocompatibility are paramount in ensuring the success of bio-printed tissues. Additionally, the interdisciplinary nature of bio-printing research fosters collaborations between biologists, engineers, material scientists, and medical professionals. This synergy facilitates the development of innovative bio-printing technologies and accelerates their translation into clinical applications. Furthermore, the evolution of bio-printing technology is not only reshaping medical practice but also opening new frontiers in scientific exploration. By mimicking the complex architectures and functionalities of native tissues, bio-printed constructs serve as valuable tools for studying tissue development, disease mechanisms, and drug responses. The ability to recreate physiologically relevant microenvironments in vitro provides researchers with unprecedented insights into cellular behavior and tissue dynamics. The bio-printing represents a transformative approach in tissue engineering and regenerative medicine, offering unparalleled opportunities for tissue fabrication, disease modeling, and drug discovery. As research in this field continues to progress, we can anticipate even more remarkable breakthroughs that will revolutionize healthcare and biomedical research.

The advantages of digital printing are emerging into commercial printing. Deinking of inkjet prints is important because they will become a sizable portion of the waste stream. Thermal inkjet ink dispersions are water-based and under certain chemical environments can remain suspended in the process water during flotation, potentially causing discoloration in a closed-loop water system during deinking [1]. Newsprint has not been a major inkjet printing category for digital commercial inkjet prints but the recycling industry has expressed concern about the deinkability of this combination. Also, while newsprint is rarely used in the office, the advent of the commercial inkjet web press will see increasing interest in the recyclability of inkjet on newsprint media, since it provides the option for deployment of newsprint media for short-life (non-archival) printing. When inkjet inks are printed on newsprint, made from wood-containing pulp with lignin, which is then included in the papermaking furnish, the problem of process water darkening can be exacerbated under some chemical conditions. Ideally, the individual sub-micron pigments and molecular dyes in inkjet ink dispersions should be collected to form larger particles of the appropriate size and also made hydrophobic for efficient flotation.In this paper, we show that inkjet-printed newsprint can be satisfactorily deinked via chemistry based on our near-neutral HPES deinking chemistry, described previously [2]. Two kinds of chemicals are used; the “E” in HPES is ethoxylated fatty alcohol, which interacts with the ink and fibers, separates them and prevents the ink from reattaching, while aggregating small ink particles into larger ones. The “S” in HPES is a small amount of an ionic surfactant added into the flotation cell, which facilitates the creation of bubbles which carry particles to the top where they can be skimmed off with the froth, leaving the clean pulp fibers to be recovered. We studied the effect of pH, collecting and clarifying agents, water hardness, chemical loading, and bleaching chemistry on filtrate darkening. In particular, we have found that the color shade and brightness of the deinked pulp and the process water can be significantly enhanced with the addition of a suitable collector or flocculating agent, in this case aluminum sulfate.

Ink-jet printing is a cost-effective technology that has had varied applications recently. The technology was applied here to an important microbiological procedure, minimum inhibitory concentration (MIC) determination. MIC evaluations were conducted by printing varying concentrations of the antibiotics, ampicillin or tetracycline, onto agar-coated glass slides then printing an even film of known bacterial density of Lactobacillus acidophilus onto the antibioticimprinted slide. Results obtained were validated with a broth microdilution technique. The MICs for ampicillin and tetracycline obtained were two-fold higher than those determined by the conventional technique.

Bioprinting is an emerging field in regenerative medicine. Producing cell-laden, three-dimensional structures to mimic bodily tissues has an important role not only in tissue engineering, but also in drug delivery and cancer studies. Bioprinting can provide patient-specific spatial geometry, controlled microstructures and the positioning of different cell types for the fabrication of tissue engineering scaffolds. In this brief review, the different fabrication techniques: laser-based, extrusion-based and inkjet-based bioprinting, are defined, elaborated and compared. Advantages and challenges of each technique are addressed as well as the current research status of each technique towards various tissue types. Nozzle-based techniques, like inkjet and extrusion printing, and laser-based techniques, like stereolithography and laser-assisted bioprinting, are all capable of producing successful bioprinted scaffolds. These four techniques were found to have diverse effects on cell viability, resolution and print fidelity. Additionally, the choice of materials and their concentrations were also found to impact the printing characteristics. Each technique has demonstrated individual advantages and disadvantages with more recent research conduct involving multiple techniques to combine the advantages of each technique.

In the search for efficient methodologies focused on up scaling production of low cost functional ceramic oxides, the implementation of Chemical Solution Deposition (CSD) in combination with drop on demand (DoD) inkjet printing technology is a challenge in materials science. When simple additive processing is implemented in continuous reel to reel systems with novel low-cost materials, the potential to further decrease the production costs of the whole manufacturing process is immense.Sets of parallel YBa2Cu3O7−x (YBCO) stripes, 250 nm thick and 150 μm wide, with critical current densities (Jc) of about 1.1 MA/cm2 at 77K and self field are obtained.On the other hand, different designs of magnetoresistive La0.7Sr0.3MnO3 (LSMO) devices with electrical resistances in the range of 10 KΩ including the contact pads, are drawn onto LaAlO3 (LAO) and SrTiO3 (STO) single crystals. We particularly investigate different strategies to increase pattern resolution and accuracy. Preliminary morphological and electrical characterizations of the device on cheaper amorphous, polycrystalline and textured substrates are presented.Therefore, this paper gives a summary of functional ceramic oxides patterning by combining CSD and inkjet printing methodologies onto different single crystal, polycrystalline and textured substrates. The present work demonstrates a powerful method of fabricating multifilamentary YBCO patterned coatings for low losses coated conductors (CC's) and LSMO magnetoresistive analog encoders for position sensing.

5 - Digital image design and creation of printed images on textile fabrics

In the recent years, thermal ink jet (bubble jet) has emerged to become a fast growing printing technology with market applications first aimed at the low end, high quality and color workstation printers. The break-through in this ink jet technology came in the areas of low cost/high volume manufacture using semiconductor thin-film processing, improved apparent reliability and the ability of high quality printing on wide range of office papers. Although the print head technology appears simple and compact, the underlining thin-film structures, micro fluid channels and drop generation process are by no mean straight-forward. In fact, the ink chemistry, the material integrity and the device physics are closely coupled to provide the proper functionality of the print engine. Hence optimization of the technology can only be achieved through complete device integration. In this paper, the basic implementations of the thermal ink jet technology is presented. The physics of bubble/drop formation process is described using results obtained from our experimental studies. Different failure modes of the electro-thermal drop generator (in particular, the thin-film resistive heater) are discussed. Results can be extrapolated to obtain a basic understanding in the requirements of the ink media and the material structure. Based on the current knowledge of this printing method, projections of the technology limitations in practical implementations can be made to support a view that thermal ink jet will become the dominant low end printing technology in the near future.