SunJet Develops Platform Inkjet Chemistry for Conductive Silver Inks
SunJet, the inkjet ink division of Sun Chemical, has developed ink chemistry designed to support and deliver conductive films using nano-particles of silver.
SunJet develops inkjet fluids for industrial applications as well as for the established market of wide format graphics. In the area of conductive ink deposition for the production of a variety of inkjet printed electronic items, SunJet has partnered with a recognized leader in the manufacture of nano particle silver. SunJet has successfully dispersed and stabilized the silver particles such that extremely reliable jetting properties can be obtained.
Nigel Caiger, Sun Chemical’s director of digital technology, said, “We have developed a platform for conductive inkjet inks based on silver nano-particles, which allows us to formulate bespoke conductive solutions for customers’ individual requirements although the initial products are based around 20 and 40 weight percent silver content. The inks can be sintered at very low temperatures, below 150°C, which is critical for some printed electronics applications, where high processing speeds are needed or the substrates are temperature sensitive.”
Peter Walshe, SunJet’s sales business development manager, said, “We have identified a number of applications (photovoltaic, sensors, touch pads, smart labels, memory and printed circuit boards) for highly conductive metal films and have already attracted a large number of partners seeking to use our capability. SunJet intends to develop a full product range and the ability to design ink properties to meet high value applications. Our work at SunJet on jettable fluids will extend Sun Chemical’s line of electronic materials under the SunTronic brand, which include dielectric materials, etch resist inks and notation inks – all fully jettable.”
DARPA Selects Bioident for Joint Development Project with Naval Research Laboratory
Bioident Technologies, Inc., the leader in the development of mobile analytic and diagnostic systems, has received a contract for the Defense Advanced Research Projects Agency (DARPA) project "Printed Diagnostic Arrays."
The goal of the project is to demonstrate the capabilities of biosensors with integrated printed optoelectronics. Together, with the US Naval Research Laboratory (NRL), Bioident is developing a portable multi-parameter detector in the form of a lab-on-a-chip system, for cost-effective point-of-use applications. The system combines microfluidics-based sensor arrays with Bioident’s printed optoelectronic sensor technology.
Mobile analytics and diagnostics are at the brink of a paradigm shift. The next generation of portable diagnostic systems will be able to efficiently perform multi-parameter measurements of tiny amounts of fluid samples, rapidly and with high precision at the point of use. However, the commercialization of such mobile applications has been hampered by the expensive and bulky optical readout equipment (lasers, CCD cameras, etc.) required with today’s systems. Eliminating expensive cameras and other optical components will reduce the size and cost of biosensor systems such as that previously developed by NRL, making a handheld sensor possible.
The goal of the DARPA-funded project is a proof of concept that printed sensors developed with Bioident’s PhotonicLab Platform technology can enable the development of cost-effective and truly mobile lab-on-a-chip systems for the point of use.
For this purpose, NRL’s original biosensor system design will be modified in two major ways: First the fluorescence assays used by NRL will be replaced with chemiluminescence assays. This eliminates the need for expensive laser excitation components. Second, the bulky readout unit (CCD camera and lens system) will be replaced with organic photodiodes, printed directly beneath the receptor antibodies in the microarray.
This technology is based on the use of organic semiconductor materials, which can be applied in liquid form onto glass or plastic foil substrates using printing technologies such as inkjet or screen print. The integration of the readout system directly onto the chip enables a minimal sample-sensor distance, providing signal detection with very high sensitivity
Microfluidic systems typically contain several reaction chambers with different reagents, simultaneously testing for the presence of multiple materials such as toxins, bacteria, viruses, and even explosives. The potential applications for this detector system range from multi-parameter detection of chemical and biological agents to medical diagnostics to environmental and food testing.
Metamaterials Improve, Open Opportunities for More Applications
In metamaterials, the ultrafine patterning and the chemistry influence the properties. Similar to the ancient Roman ruby glass containing gold chloride in very fine particles. It gave different optical effects at various angles thanks to both the chemistry and the physics.
Metamaterials are a hot topic because they can lead to unusually thin lenses and other previously impossible printed electronics. Here, both fine three-dimensional patterning - much less than the wavelength of the electromagnetic radiation being emitted - and inherent material properties are used to modify several overall properties. An example is negative permeability and permittivity leading to negative refractive index.
These counterintuitive effects are sometimes achieved by flexographic printing, for instance, of arrays of tiny split rings as resonators with microwires. One theoretician is asking engineers to print what he describes as nanoscale hedgehog shapes. Appropriately made, these materials with repeated three dimensional structures less than the wavelength of the radiation used will break the traditional laws of optics and magnetics because they employ quantum effects.
Following the original prediction of such effects by Russian physicist Victor Veselago in 1968, the practical demonstrations have now come from teams in the UK, US and elsewhere. Negative refractive index has now been demonstrated for microwave and terahertz radiation which may lead to new types of beam steerers, modulators, band-pass filters, microwave couplers and antenna radomes.
There is even talk of making things invisible by so called masking with these patterned materials and limited demonstration of such effects has been made from microwave to optical frequencies. Indeed, in 2007, Ames Laboratory of the US Department of Energy and California Institute of Technology Pasadena, working with Karlsruhe University in Germany, demonstrated a metamaterial with a negative refractive index to both red and green visible light. It had very fine patterning on both sides of a thin dielectric.
Researchers now develop working metamaterials in Canada, the US, Switzerland, the UK, Germany and East Asia. For example, the terahertz range is promising for automated inspection, zero-visibility navigation, biomedical imaging and security screening applications notably with solid-state sensors that can see through solid objects. At radio frequencies smaller antennas are in prospect, indeed a new European Commission program targets smaller RFID tags. In vehicle radar anti-collision systems may become more practicable, say some researchers. Metamaterials for acoustic, rather than electromagnetic waves are also being studied including making buildings invisible to earthquakes.
Universal Display Corp. Reports Flexible OLED Display Improvements
Universal Display Corp., a displays and lighting products innovator through its Universal PHOLED phosphorescent OLED technology, has developed a new, thin flexible, active-matrix OLED (AMOLED) display prototype built to date. Resulting from Universal Display’s collaboration with Professor Jin Jang of Kyung Hee University, the Company’s research demonstrates significant flexibility enhancements and AMOLED robustness when built on ultra-thin metallic foil substrates. This work will be reported in a joint paper at the Society for Information Display (SID) 2008 International Symposium, Seminar and Exhibition at the Los Angeles Convention Center in Los Angeles, CA.
A joint paper, discusses the successful fabrication of a low-power flexible AMOLED device built on ultra-thin (25µm) metallic foil substrate. The monochrome device combines an amorphous-Silicon (a-Si) backplane developed and fabricated by Professor Jang’s team with a top-emission, phosphorescent OLED front plane from Universal Display. Through flexibility testing, the work shows that these backplanes can operate effectively when conformed repetitively to a tight diameter of 5 millimeters. This is significant in that it demonstrates additional feasibility for product concepts such as the Company’s Universal Communication Device.
“We’re excited to announce advances in the flexibility and ruggedness of ultra-thin OLED displays, the result of a successful collaboration with our world-class collaborators at Kyung Hee University,” said Steven V. Abramson, president and Chief Executive Officer of Universal Display. “These advances support our initiative to develop flexible OLED display technologies for military and consumer applications, including a ‘roll-out’ OLED display for our concept Universal Communication Device.”
DisplaySearch, a worldwide leader in display market research and consulting, projects that the worldwide market for flexible displays has the potential to grow to $4 billion in 2015. Universal Display has been working with the US Department of Defense to develop highly efficient and ruggedized AMOLED displays on metallic foil substrates for use in harsh battlefield conditions. Flexible OLED displays, widely considered to be the next major breakthrough display technology, also offer key advantages, such as an ultra-thin form factor, for a variety of novel consumer applications.
GE Global Research Demonstrates Feasibility of Thin Film Encapsulation for Flexible OLED Displays under Cooperative Program with USDC
The US Display Consortium (USDC), a public/private partnership chartered with developing the flexible electronics and displays industry supply chain, has completed a cooperative R&D program with GE Global Research — with the potential to accelerate commercialization of flexible organic light emitting diodes (OLED) displays. GE has demonstrated an ultra high barrier (UHB) thin-film encapsulation process on a wide variety of OLED structures through a batchmode, plasma-enhanced chemical vapor deposition (PECVD) process. This encapsulation method solves a critical need in the display industry for high-performance, hermetic packaging and enables lightweight, flexible rugged flat panel devices to be manufactured by a low cost, high throughput process such as roll-to-roll manufacturing (R2R).
The encapsulation studies were performed on OLEDs from several leading companies working in the emerging flexible and printed electronics industry. Goals of the program included, demonstrating flexibility and achieving luminescence-current-voltage (LIV) characteristics, as well as shelf and operational life performance comparable to glass and metal encapsulated OLEDs.
“Encapsulating OLEDs presented a significantly different challenge from our previous success in producing barrier-coated plastic substrates,” said Dr. Ahmet Gün Erlat, materials scientist at GE Global Research. “The USDC-funded program provided GE with the opportunity to further develop key technologies and applications that can dramatically impact the flexible electronics infrastructure.”
“GE demonstrated this new technology in partnership with USDC member companies developing OLED displays and lighting,” said Dr. Mark Hartney, USDC’s chief technology officer. “They have demonstrated equivalent performance to glass substrate barriers, as well as the capability of the barrier to withstand extreme flexing conditions. This will greatly enhance the industry’s knowledge base for encapsulating OLEDs on flexible substrates.”
Optomec and Manz Automation Enter Partnership Agreement
Optomec, a company focused on printed electronics for solar, display, aerospace and life science applications, has entered into an exclusive OEM partnership agreement with Manz Automation AG to jointly pursue applications in the Solar market.
Manz Automation AG, based in Reutlingen, Germany, is a supplier of automation, inspection, chemical wet processes and laser process technology for the photovoltaic and LCD industry.
As part of the agreement, Manz will integrate Optomec’s patented M³D Aerosol Jet deposition system into their back-end solar cell manufacturing lines to allow contact free deposition of metal collector lines. Optomec’s M³D printing solution is able to print much finer lines than is currently possible with traditional screen-printing. These narrower, high integrity collector lines have higher conductivity and a lower shadowing effect, thereby increasing photovoltaic cell efficiency. In addition, because the process is non-contact, Optomec’s M³D process can print on thinner wafers and with less breakage than screen printing techniques. The Optomec print solution, together with an additional electroplating process, has shown efficiency improvements of 0.5 to 1percent and greater in absolute figures.
Both companies have begun the integration work of the Optomec M³D Aerosol Jet system into the Manz metallization system. It is the intention to ship the first customer systems before the end of 2008.
Plextronics Signs MOU to Supply Its Solar Cell Technology to Korean Manufacturing Company
Plextronics, Inc. has signed a non-binding memorandum of understanding (MOU) with Korea Parts & Fasteners (KPF) to create a research and development center for organic photovoltaic process development in Korea. The agreement specifies that Plextronics will focus on advancements in its active layer inks for solar cells and to provide certain baseline device and process technology to the new R&D facility, which will be built outside of Seoul.
Upon reaching a definitive agreement with Plextronics, KPF's role would be to develop advanced process technology using Plextronics' inks and device and process technology.
"Our strategy is to participate in R&D centers with manufacturing customers all over the world who we believe could be major manufacturers of OPV products," said Andy Hannah, CEO of Plextronics. "This venture with KPF is our first step in this strategy."
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ZBD, innovator in LCD e-paper technology, has introduced the latest addition to its family of electronic point of purchase displays. The EPOP 300, developed in response to customer demand, expands the choice of display sizes on offer from ZBD and, for the first time, gives the option of employing high-impact promotional color. 
Osram Opto Semiconductors and lighting designer Ingo Maurer have unveiled a new lighting application based on OLEDs. Ingo Maurer is the first to use Osram OLEDs in a functioning table light. OLEDs are composed of thin films of organic molecules and use less power than conventional light-emitting diodes. The limited-edition lamp, titled “Early Future,” shines with Osram OLED tiles and demonstrates the enormous potential of using OLEDs to create future applications with eye-catching illumination and creative design elements. 
SEMICON West 2008