It has taken years for ink jets to move from the laboratory to the home, office and commercial workplace. Commercial ink jet printing literally began on the floor with Miliken's carpet printers in the 1970's, but it was not until HP's ThinkJet that enabled everyone to inexpensively print from PC's did ink jet printing become a common term. Now we are seeing many markets utilizing a wide variety of ink jets in ways unthinkable 30 years ago. These applications include every form of graphics arts printing, product decoration and even fabrication of products and components.This presentation will discuss recent advances in drop-ondemand piezo ink jet technology with particular emphasis on designs intended for dispensing functional fluids rather than printing inks. Recently new methods of constructing printheads have been introduced and these tools are enabling new applications in areas as diverse as biotechnology, nanofluid development and flexible organic electronics. We know from looking at billboards and address labels that ink jets produce valuable graphic arts products, but it remains to be seen if ink jets can move from industrial and university labs into volume manufacturing of products such as displays and biochips.

Inkjet printing is known to be a low cost and flexible technique for the controlled deposition of functional materials for applications in polymer light-emitting devices (PLEDs), solar cell devices, organic field effect transistors (oFETs) and tailor-made high-tech coatings. Moreover, it can be considered as a library preparation technique of functional polymers or nanoparticles allowing a systematic variation of parameters (e.g. thickness or chemical composition) for combinatorial studies. The presented research deals with two different and significant topics: investigations of ink formulations (using isolating, conducting and semi-conduction polymers as well as semi-conducting nanoparticles) and the systematic variation of the utilized surfaces of the respective substrates as well as the optimization of the printing conditions to improve the quality of inkjet printed films. Moreover, the application of inkjet etching will also be addressed.

The issue of color is now receiving considerable attention in the applications of imaging technology. It is difficult to reproduce the original color of subject in conventional imaging systems, and it obstructs the applications of visual communication systems in telemedicine, electronic commerce, and digital museum. Recently, the color videos, still-images, and prints are reproduced with significantly better quality than before, but there still remain limitations imposed by RGB trichromatic system. To breakthrough the limitation of RGB 3-primary systems, “Natural Vision” system has been developed aiming at an innovative visual communication technology, which enables high-fidelity color reproduction, based on spectral information. The experimental multispectral systems for both still-image and video have been elaborated and shown following features of spectrum-based scheme; a) Highly accurate color reproduction is possible with multispectral imaging, even under different illumination environment. b) Extended color gamut can be reproduced by multiprimary color displays. c) The influence of observer metamerism, which is considered as a cause of color disagreement between different media, can be reduced by the spectral color reproduction. d) The quantitative spectral attributes of object, useful for the analysis or the recognition of object, are captured and preserved. In addition, the effectiveness of the system has been demonstrated through experiments in the application fields, such as medicine, digital archives, color printing, electronic commerce, and computer graphics.

Metal oxides like titanium, alumina and silica are key ingredients of dry based electrophotographic toners and ink jet paper coatings. Solid state parameters, like crystal structure, particle size, morphology and porosity favor their use in these applications. However, a variety of further requirements like tribochargeability, and stability, particle surface charge, in terms of powder toner applications and ink jet coatings, have to be fulfilled. As a consequence new surface chemistries of the metal oxides are required.This presentation will focus on how metal oxides can be tailored for NIP applications. Special focus is given to synthetic amorphous silicas (SAS). The impact of selected physical-chemical features like particle size (primary, aggregate, agglomerate), surface chemistry (silylation), porosity (e.g. mesoporous for fumed metal oxides), particle surface charge (e.g. anionic or cationic), and their correlation to relevant application properties, for powder toners, like tribocharge and stability, flow, transfer efficiency, and cleaning, and for ink jet coatings, like adsorption and absorption capacity, gloss, waterfastness, and bleeding is discussed.Newer technologies like chemically prepared toner (CPT) or photoglossy papers and their impact on metal oxides for NIP are considered.In addition, EH&S aspects of SAS and an update on chemical legislation will be covered.

Microfabrication approaches such as printing with micro and nanoscale resolution have dramatically changed our society through their use in diverse fields. These engineering tools are also useful for many biological applications ranging from drug delivery to DNA sequencing since they can be used to fabricate small features at a low cost and in a reproducible manner. In addition, the ability to print materials at the micro and nanoscale is potentially important for many biological and biomedical applications. Our goal is to use these techniques to better understand and manipulate cell behavior (e.g. stem cells) and to fabricate devices for high-throughput screening. This talk will describe new materials and methods developed in our lab to regulate and analyze the interaction of cells with their surroundings. To control cell migration and to restrict cell or colony size, cells and proteins were patterned using numerous printing and molding methods based on deposition of polymers. To control cell-cell contact, we have developed methods based on layer-by-layer deposition of ionic biopolymers to generate patterned co-cultures. In addition, we have developed microfluidic-based approaches to synthesize novel materials and to interface cells inside microdevices.

Organic electronic systems offer the possibility of lightweight, flexibility and large area coverage, properties not easily achievable with standard silicon technology, and at potentially lower manufacturing costs. DuPont has focused on the development of conducting and semiconducting organic materials that allow for the printing of active and passive electronic devices. A number of groups have focus in improving device performance by designing organic semiconducting materials of higher mobility. We demonstrate an alternative path for achieving high transconductance organic transistors in spite of relatively large source to drain distances. The method, based on creating subpercolating conducting networks, would enable the printing of submicron features with conventional commercial engines. The improvement of the electronic characteristic of such a scheme is equivalent to a 60-fold increase in effective mobility without reduction of the on/off ratio.These conducting and semiconducting composites are compatible with various large area printing processes such as thermal and ink jet. However, the manufacturing of complex multi-layer circuits over large areas in a reel-to-reel configuration has been one of the driving forces in the organic electronics field. We are currently evaluating the feasibility of micro-contact printing as a path to high-resolution reel-to-reel electronics. Thus extending flexography into the high-resolution arena. Unlike conventional lithography, micro-contact printing; not requiring sacrificial resists, developers, and etchants; maybe compatible with a wider range of materials and substrates currently utilized in plastic electronics.

Mass printing technologies are promising technologies for the production of inexpensive electronics.In recent experiments, we have fabricated an integrated circuit solely by means of fast mass-printing methods without any steps breaking the production continuity. Our results clarified important issues that have to be taken into account when adapting printing technologies to the fabrication of electronics. Compatibility of materials and processes for the deposition of different layers on top of each other, uniformity and quality of layers with respect to electronic requirements as well as resolution and registration turned out to be challenging for the adaptation of printing technologies.In addition, first applications are already available, which rely on simplicity and inexpensive fabrication instead of high integration and high-end performance. Flexible cardboard-keyboards, chipless paper-identification systems as well as simple sensor systems can be regarded as applications that are paving the way for more sophisticated, printed electronics applications.

For several years there have been many efforts to employ ink jet technologies in the fabrication of consumer electronics. The potential of displacing large and expensive pieces of electronic fabrication equipment and processes with seemingly appropriately scaled inexpensive alternatives is attractive. However, of course, the devil is in the details. Feature size, accuracy, registration and materials all have severe impacts on design rules, processing, performance and the types of devices appropriate to the technology. In this article, we describe aspects of the jet-printing technology for large-are electronic device processing that have been developed at PARC. These aspects include fine feature patterning, multi-layer registration for thin-film transistor device fabrication, printing of solution processable semiconductor and conductive materials, and printer color filters. The focus of this work is to demonstrate the wide range of applications for jet printing in the area of device processing.. Examples of working proto types of displays, imagers and microfluidic devices produced through ink jet printing are given and we discuss the tools used to design these devices.

Digital printing has garnered significant attention in recent years as a pathway to ultra-low-cost electronic systems. In particular, given the low viscosity requirements of inkjet printing, this has been a leading candidate technology for realization of allprinted electronic devices. We have developed inkjet-compatible materials for a full range of electronic materials, including printed conductors for interconnects and antennae, dielectrics for capacitors and transistors, and semiconductors for active devices. Using various combinations of nanoengineered particles and organic materials, we have realized fully printed transistors, diodes, and passive components with performance approaching the requirements of various applications including displays, sensors, and low-cost RFID tags. We review our materials technology, report on advanced devices fabricated using these materials, and discuss the implications of the same on the viability of fully-printed circuits.

Printed electronics will bring major advantages for simple electronic products like RFID (radio frequency identification) tags, displays and smart objects. PolyIC develops a printing process in which electrical conducting and semi conducting plastics, so called polymers, are applied in several layers on a polyester film to realize electronic functionality.