The Ink-jet method is the effective technology as a process to functionalize the by setting a functional material required for a required place. But conventional inkjet technology has a limitation in resolution of a few tens of micro-meters. We have developed a super-fine ink-jet technology (Super Ink Jet - SIJ) that enables the formation of fine features less than a micro-meter in diameter. Furthermore, the printing method is not limited by the tight viscosity requirements of normal inkjet inks and allows the use of a wide variety of inks: e.g. nano-metals, semiconductors, insulators, light emitting polymers, bio-materials etc. Using this method, the direct fabrication of circuits and three-dimensional structures with feature sizes of just a few microns has been achieved. The potential of the SIJ technology and its application to cutting-edge areas, such as flexible and printed electronics, fine-pitch direct interconnects and others will be shown.

Digital textile printing technology has become one of the production textile printing processes since introductions of production digital printing systems in early 2000's. However, over a decade since the introductions of the technologies, current utilization of digital printing technologies in the industrial textile printing sector is still small in contrast with the popularity of conventional textile printing systems. This paper focus on the current state of digital textile printing in terms of engineering, business and design based on empirical research, including international case studies and field trips over the past 10 years. The supply chains from engineering to user standpoints (mills, printing service operations) will be investigated. At the same time, the emerging new field of Surface Imaging, will be ascertained.

Typical commercial ink-jet print heads can eject fluids with viscosities up to 30-40 cP. However, most polymers of interest for mechanical parts have viscosities that are orders of magnitude higher than this; hence there is a need for print heads that can eject high viscosity fluids. After a brief survey, this talk will introduce a high viscosity print head based on an ultrasonic atomizer technology that was developed at Georgia Tech. The bulk of the talk focuses on the development of two types of models: ultrasonic atomizer modeling and droplet impingement modeling. In the first area, both high fidelity and simplified electromechanical models will be presented, with the objective of understanding and improving the pressure gradients in the atomizer nozzle. In the second area, a new Lattice-Boltzmann-based fluids model was developed to simulate droplet impact and droplet interactions in order to determine process conditions that enable the formation of planar films without splash. Implications of the research on printing process and ink developments will be provided. Also, some limits on how high is “high viscosity” will be offered.

In nanophotonics, we create material-systems which are structured at length-scales smaller than the wavelength of light. When light propagates inside such effective materials, numerous novel and exciting phenomena can emerge, enabling a variety of novel applications. However, in order to make use of these opportunities for many real-world applications of interest, one has to have the ability to implement nanophotonic structures over large scales. Printing techniques are often useful for implementation of such structures, especially when the wavelength of interest is sufficiently long. In this talk, I will present some of our recent theoretical and experimental progress in exploring these opportunities, as well as novel physics phenomena that emerges in this process.

Digital printing technologies are demonstrating strong growth due to their on-demand capability, which enables short run, varied-lot printing with rapid turnaround. Key growth segments in which piezo inkjet technology is recently increasing its presence are commercial, industrial and business printing, which demand professional quality and high productivity. Piezo inkjet technology uses mechanical energy rather than heat for ejection, enabling various types of ink to be used – from non-aqueous UV inks to water-based pigment inks.Thus far, we have developed MACH printheads with 120-180 npi/row nozzle resolution by enhancing the process of precision machining bulk piezo and ink channel components [1-5]. Using a different approach, we dramatically raised the nozzle resolution with TFP (Thin Film Piezo) technology in 2007 [6]. TFP's high displacement piezo, with a thickness of around 1 μm, made it possible to increase the nozzle resolution up to 360 npi/row. We have since utilized TFP as our flagship technology in large format printers.Now, with a next-generation actuator chip, we have succeeded in broadening the application of TFP technology into a wider range of printing segments, from desktop serial printers to industrial linehead presses. In this paper, we explain this nextgeneration inkjet technology, which achieves high output quality, high speed printing and improved scalability through the miniaturization of the core chip.

We developed a new inkjet head by applying MEMS technology and thin film piezo actuator. Jetting properties of inkjet heads were calculated by the simulation method of the equivalent circuit model generated from actuator properties and ink flow channels of the inkjet head.We manufactured a test piece to investigate the jetting properties and oscillation forms of the actuator. As a result, our test piece was driven at maximum 70 kHz and ejected 3 pl droplet with an ink which viscosity was 10 mPa · s. We found that the experimented jetting properties and vibration forms agreed very well with the simulation.

SII Printek produces printheads characterized by their high productivity. Our ink-jet printheads realized such high productivity with edge shooter structure operating in shear mode until now. Most especially, 508GS model has been popular covering a wide range of ink chemistry and capable of jetting at a high frequency thanks to its isolated channel structure. However, even higher stability at high production rate is demanded in any industrial market, particularly those prints in single pass. Hence we developed a new product which adopted the following techniques to cope with such demands.Firstly, we adopted side shooter structure where a nozzle is located in the center of pressure chamber with openings at both ends to enable ink circulation across. Thereby we can save a large quantity of ink consumption wasted for filling of ink and cleaning of nozzle. Continual ink flow beside the nozzle realizes self-recovery of meniscus as well.Secondly, we adopted our isolated channel structure where discharging and non-discharging channels are alternately grooved and only the latter are actively driven.In this way, electrodes of discharging channels immersed in ink are free from any corrosion and active channels can operate at a high frequency since they are isolated from each other and hence free from crosstalk.Thirdly, we adopted a cantilever structure where the channel walls of the actuator are held rigidly by stiff material at one end and flexibly at the other, from which electrodes extend covering about half height of the wall. This allows us to effectively drive the discharging channel without too much modifying the simple conventional process. Incorporating these three structures together allows us to jet a large volume of drop at a high frequency, but such a large ink flow digitally driven causes big pressure shock occurring at onset and end of a print streak, starving and over-pressuring the printhead in turn. We introduced a dumping structure to supress such a big shock affecting the actuator operation. Thus we could achieve good printing sustainability that can endure any pressure fluctuation, not only due to sudden change in pinting streak but also from outside disturbance. In conclusion, our new inkjet printhead RC512 realized very high productivity and sustainability for industrial printing.Its productivity exceeds our existing product lineup by far, and we are amazed to see a stable discharge is possible with such productivity. We are further developing a new model evolved in the line of this structure aiming at even higher performance.

To date, there are limited options in the ability to create droplets of smaller radii than that of the nozzle from which they are produced. Existing methods pertain largely to piezoelectric inkjet printing and time scale manipulation rendering them inapplicable to thermal inkjet technologies. In this work, a simple method for drop volume control in inkjet systems is proposed in which stable drop volume can be reduced by an order of magnitude with a constant nozzle radius by adjusting the back pressure in the reservoir that supplies the print head. The back pressure is regulated, droplet sizes, stability, and velocities are recorded. These results are then corroborated by rigorous modeling.

Xaar has deployed its Hybrid Side Shooter™ actuator technology successfully in its Xaar 1001/2 printhead. The ejection of ink from the ‘side’ of the ink channel and not the conventional ‘end’ of the ink channel has enabled it to use its patented Through-Flow technology (TF Technology™): This has transformed printing reliability and has led to the adoption of digital ink jet into single pass industrial printing; most noticeably for printing decoration of ceramic tiles. Xaar has now developed a new edge-mounted actuator architecture, which builds on the advantages of the side-shooter actuator and enables the capability to produce compact multiple row printheads and also improves manufacturing efficiency by using a ‘wafer-scale’ approach. This paper details some of the advantages of this new edge-mounted actuator architecture.

We have previously studied DoD jetting of complex model fluids based on dilute polymer solutions, resulting in the identification of a new regime of polymer jetting and some basic rules for predicting the limiting polymeric concentrations under real conditions such as print head nozzle diameter, jetting speed, solvent quality and polymer molecular weights [1, 2]. There has been no systematic experimental study of the effect of particles on DoD scale jetting, despite the ground-breaking work by Furbank and Morris [3] as reported in NIP17 for the effects of particles on dripping, although theoretical modelling for liquid bridges/filaments containing particles has been recently published [4] and could be relevant to local thinning of DoD ligaments.A series of pigmented inks in the solvent dipropylene glycol methyl ether (DPM) has been used to help study effects of pigment particle size (d₉₀ = 3.6, 2.6, 1.6, 1.0, 0.8 μm) on DoD jetting. These inks contained 35 wt% of the inorganic black pigment copper chromite and had a low shear-rate viscosity of ∼ 15 mPa s. Ink characterisation used a high frequency rheometer [5] and a novel fast (5 m/s) filament stretching device [6, 7], while the DoD jetting used MicroFab 80 μm diameter nozzles [8]. Jetting experiments were performed at 100 Hz to avoid nozzle clogging.We report the first systematic experimental studies for DoD scale jets of characterized inks comprising (a) particles in DPM; (b) resin DPM; and (c) combinations of particles and resins in DPM [9, 10]. These results will provide new insights into the jetting of pigmented inks and be important for new applications.