13 research outputs found
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Standardization Of Inkjet Drop Speed Measurement Methods For Printed Electronics
This is the author accepted manuscript. The final version is available from the Society for Imaging Sciences and Technology via http://ist.publisher.ingentaconnect.com/contentone/ist/nipdf/2015/00002015/00000001/art00029Methods for measurement of inkjet-printed drop speed at various precision levels were proposed in a draft international standard by IEC TC119: Printed Electronics WG3 - Equipment. These are reviewed and discussed for feedback by NIP31/DF2015
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A Simple Model for DoD Inkjet Frequency Response
This is the author accepted manuscript. The final version is available from the Society for Imaging Sciences and Technology.A simple linear model of piezo DoD inkjet print-head jetting output (drop speed, volume, momentum) provides an analytic prediction for the frequency response for steady state and initial printing streams from nozzles. The model has been applied to both existing commercial and development inkjet print-head devices.This work was performed under a UK EPSRC Impact Acceleration Knowledge Transfer Fellowship (grant no. EP/K503757/1). Xaar and other consortium members within the I4T (innovation in industrial inkjet technology) project (grant no. EP/H018913/1) gave permission to publish the results and also provided further support. Mario Massucci and Marko Dorrestijn (Xaar Cambridge), and Eva Singler and Ingo Reinhold (Xaar Sweden), all shared their piezo DoD print-head data for this paper
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Multi Pulse Train Modeling of Piezo-Drop-on-Demand Inkjet Print-Head Response
Resonant oscillations set up internal fluid waves within a piezo-DoD print-head channel as a result of actuation drive pulses. Such waves will persist for some time after droplet ejection from the nozzle, and the residual wave amplitude can interfere (constructively or destructively) with all succeeding actuation drive pulses, potentially altering the speed and volume of successive droplets. As uncontrolled interference would worsen printing quality, residual waves are usually reduced by a combination of print-head design and waveform optimisation for better performance at continuous (steady-state) printing frequencies. However, the residual waves following any changes of printing frequency can influence “first” drops and short bursts of drops. Exact analytic expressions are provided here for the N-pulse burst DoD print-head response function with fixed printing frequency. The present paper explains the purpose and application of the model predictions to published piezo-driven DoD data. An examination of the effect of fluid properties, the identification of unexpected jetting behaviour and some issues with manufacturing prototype quality, tests of assumptions made in the simple model and extensions to the prediction of print-head performance using realistic complex waveforms are also discussed. An earlier shorter report, mainly introducing the multi-pulse train modelling approach and some applications within Xaar, was first presented at NIP31/DF2015.This work was supported by an EPSRC Impact Acceleration Knowledge Transfer Fellowship (Grant no. EP/K503757/1) and industrial funds from the Inkjet Research Centre at the University of Cambridge. Xaar and other consortium members within the I4T (innovation in industrial inkjet technology) project (Grant no. EP/H018913/1) gave permission to publish earlier results in NIP31/DF2015 and also provided further support.This is the author accepted manuscript. It is under an indefinite embargo. The Society for Imaging Sciences and Technology have not yet published it
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Meniscus Motion Inside A DoD Inkjet Print-Head Nozzle
This is the author accepted manuscript. The final version is available from
the Society for Imaging Sciences and Technology via http://www.ingentaconnect.com/contentone/ist/nipdf/2016/00002016/00000001/art00087A new study of the jetting performance for drop-on-demand (DoD) inkjet print heads investigated meniscus motions inside the transparent nozzles of MicroFab inkjet print heads. A composite image representation of the observed meniscus motions, imaged at high resolution using a spark flash light source, was developed for our subsequent analyses of the influences of drive voltage and pulse dwell time and also the ink properties. At higher drive voltages a slow damped refill (following de-pinning of the meniscus from the very edge of the nozzle exit) was also clearly observed. This and many other interesting phenomena were observed with the composite images: internal bubbles that progressed through the nozzle region over relatively long timescales, internal break-off of the jet from the meniscus surface, satellite formation and merging, and the contact line de-pinning not previously observed before.This research was performed by CSR under the Undergraduate Research Opportunities Program (UROP) scheme, within the University of Cambridge Inkjet Research Centre, funded by Xaar Ltd. SDH supervised and held an EPSRC Impact Acceleration Knowledge Transfer Fellowship (grant no. EP/K5037574/1) for working with a Xaar R&D team during the initial part of this project
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Review of digital printing technologies for electronic materials
Abstract: Direct printing methods have been used as manufacturing tools for printed electronics applications due to their cost effectiveness. In this review, the piezo-driven inkjet is discussed in detail since it is a mature technology and suitable for the production printing of printed electronics. In addition, other printing methods are considered for using higher viscosity ink and for producing smaller printed feature size. Various direct printing methods are compared in terms of jet mechanism, printing algorithm, and their applications. In particular high resolution printing methods using high viscosity inks, such as electrohydrodynamic jet, aerosol jet and micro-plotter are reviewed. To understand the recent status of industrial printing applications, display (liquid crystal display and organic light emitting diode) materials and printing issues are discussed. Finally, a brief overview of nano-particle metal based conductive inks is included because these inks have been widely used for printed electronics applications
Recommended from our members
Review of digital printing technologies for electronic materials
Abstract: Direct printing methods have been used as manufacturing tools for printed electronics applications due to their cost effectiveness. In this review, the piezo-driven inkjet is discussed in detail since it is a mature technology and suitable for the production printing of printed electronics. In addition, other printing methods are considered for using higher viscosity ink and for producing smaller printed feature size. Various direct printing methods are compared in terms of jet mechanism, printing algorithm, and their applications. In particular high resolution printing methods using high viscosity inks, such as electrohydrodynamic jet, aerosol jet and micro-plotter are reviewed. To understand the recent status of industrial printing applications, display (liquid crystal display and organic light emitting diode) materials and printing issues are discussed. Finally, a brief overview of nano-particle metal based conductive inks is included because these inks have been widely used for printed electronics applications
Recommended from our members
Review of digital printing technologies for electronic materials
Abstract: Direct printing methods have been used as manufacturing tools for printed electronics applications due to their cost effectiveness. In this review, the piezo-driven inkjet is discussed in detail since it is a mature technology and suitable for the production printing of printed electronics. In addition, other printing methods are considered for using higher viscosity ink and for producing smaller printed feature size. Various direct printing methods are compared in terms of jet mechanism, printing algorithm, and their applications. In particular high resolution printing methods using high viscosity inks, such as electrohydrodynamic jet, aerosol jet and micro-plotter are reviewed. To understand the recent status of industrial printing applications, display (liquid crystal display and organic light emitting diode) materials and printing issues are discussed. Finally, a brief overview of nano-particle metal based conductive inks is included because these inks have been widely used for printed electronics applications
Atomization patterns produced by the oblique collision of two Newtonian liquid jets
This paper reports a detailed experimental investigation of the formation, destabilization, and atomization of the liquid sheets created by the oblique impact of two laminar jets of a Newtonian liquid. Glycerol-water mixtures with viscosities between 4 and 30 mPa s were used to investigate the effects of viscosity and jet velocity. The jets were ejected from parallel cylindrical nozzles with an internal diameter of 0.85 mm. Collision of the jets resulted in various regimes of behavior which depend on the jet velocities and the liquid properties. We focus on the regime where the impinging jets form a liquid sheet which then breaks up into a regular succession of ligaments and droplets, a so-called "fishbone" pattern. We use short-duration, single-flash illumination combined with high-resolution digital photography to study the evolution of the sheet, its shape, and the form, size, and spacing of resulting ligaments and drops. Unexpectedly, we found fishbone regimes corresponding to lower Reynolds and Weber numbers than had been previously reported; furthermore our apparently symmetric fishbone structures were definitely associated with asymmetric, rather than symmetric, impacting jet conditions. The fishbone structure was found to be significantly affected by any asymmetry in either the free lengths of the two jets or their alignment. The fishbone angle, defined as the angle between the lines through the first pairs of droplets on each side of the fishbone structure, is introduced to describe the effects of differences in jet length, alignment, or fluid properties on the degree of development of the fishbone pattern. We discuss how changes in the various parameters influence the form of the fishbone pattern and the origin and mechanism of the periodic atomization of the sheet. In particular we find that the dependence of the drop spacing on viscosities is consistent with the Rayleigh-Plateau instability on the rim provided the variation of the rim width is properly included, as this dominates the Ohnesorge number dependence of the breakup.open113031sciescopu