JAPERA (Japan Advanced Printed Electronics Technology Research Association) has developed a basic technology to create OTFT array with all printing. In accordance with the requirements of each component, various printing methods including inkjet are used selectively to realize a high-precision flexible pressure sensor array by full printing. A high resolution active matrix type pressure sensor was made on the film base material and the sensor surface was covered with a thin rubber sheet with the same thickness as the sensor pitch. In this research, we apply our printed flexible pressure sensor to robot skins and show examples of tactile judgment and two-way communication at high speed by using obtained pressure distribution.
A route for the inkjet-printing of organic rectifying diodes based on Metal-Insulator-Semiconductor (MIS) structure is outlined. The proposed strategy is based on a layer stack of two silver electrodes between which a polyvinyl phenol (PVP) insulator layer and an amorphous organic semiconducting layer are sandwiched. Thanks to the energy barrier given by the presence of a leaky dielectric layer between the electrode and the semiconductor, the current versus voltage characteristics present a rectification ratio of up to 1.5*103 at |10 V| and a current density up to approximately 0.1mAcm-2. Finally, a first example of a gas sensor based on the MIS diode is presented as a proof-of-concept for the possible applications of these structures.
With the development of technologies in printed electronics, the products more personalized, irregular and customized application are more and more welcome. Nowadays, technologies have solved many technology problems such as circuit conductivity, functional inks, printing method, substrate, etc. In this paper, the aim is to achieve different LED display by same background circuits. We designed the common circus that suited personalized various appearance with low cost. Then we tried irregular circuit to achieve different effect. This study attempts to show the important ways on design and art, to help optimize ways to special pattern application.
In this paper, carboxymethyl cellulose was used as matrix and graphene was used as conductive filler, compounding graphene with carboxymethyl cellulose. To prepare graphene/cellulose composite conductive film, the composite effect of it was discussed. Firstly, graphene was prepared by chemically reducing graphene oxide with ascorbic acid as reducing agent, and its conductivity was up to 110.2 S/cm. And then, graphene and carboxymethyl cellulose were composited by physical blending. When the mass ratio of graphene oxide to carboxymethyl cellulose was GO:CMC=1:6, the electrical conductivity of the composite film was 8.5×10-2 S/cm. Finally, graphene/cellulose composite conductive film was prepared by coating a graphene/cellulose composite system on a polytetrafluoroethylene substrate.
Inkjet printing, the digitally-controlled deposition of microdroplets onto a substrate, presents a number of potential advantages as a polymer additive manufacturing technique due to a relatively high spatial resolution and the ability to easily deposit multiple materials in one structure. It is, however, fundamentally limited by the low viscosity of the printed ink, which limits both the amount of solid phase present within the ink or necessitates the use of post-deposition curing of the ink to form the structure. Micro-reactive inkjet printing attempts to circumvent these limitations by exploiting the controlled in-air collision of two complementary reactive microdroplets, so as produce a microdroplet of the desired product before impact with the substrate. In this work, we explored the formation of polyaniline (PAni) on glass substrate through oxidative polymerisation of aniline in an acidic environment via a microreactive inkjet printing technique. We successfully printed different patterns of polyaniline onto glass substrates, as shown by microscopy and spectroscopy, and a conductivity of approximately 0.6 S cm-1 was achieved. We envision this printing technique to be particularly useful for a wide range of conducting polymer synthesis in the future.
The technological advancement in the field of printed electronics over roll-to-roll (R2R) platform has become very attractive, because of the several advantages such as mass production, large area application, cost-saving and high-speed capabilities. The inkjet technology, on the other hand, among other printing technologies promotes individualization and contact-less deposition process qualities. In this article, the authors demonstrate the state of the art R2R setup for printing silver (Ag) conductive patterns on PEN substrate using inkjet and infra-red technologies. The deposition of the conductive patterns was accomplished using a nanoparticle-based Ag ink and industrial printheads from Fujifilm Dimatix. The novelty of the research work is realization of a print setup, consisting of an industry relevant flexible printhead assembly and drop evaluation station, which are mounted over a R2R printing system. The entire setup allows the user to first evaluate the ejection of the droplets and then stabilize the print parameters without involving the web substrate, followed by re-positioning of the inkjet assembly back to the R2R printing system. The capability of the print setup is exhibited by varying the printing resolution for the defined digital patterns. In addition, the post-treatment of the conductive patterns was tailored with the implementation of an infra-red based sintering module from Heraeus Noblelight GmbH. The power density of the filaments from the sintering module was varied to achieve the maximum conductivity and to ensure no physical damage to the patterns and substrate. The results indicate that such a print setup is very flexible and can offer several benefits to the printing process of conductive patterns, e.g., obtaining line width below 80 μm and sheet resistance of about 0.5 Ω/ , with the advantage of sintering the patterns within 20 s. © 2018 Society for Imaging Science and Technology.
Fully inkjet-printed multiwall carbon nanotube (MWCNT) layers and their feasibility towards the implementation as a low cost and flexible sensing element is reported. The focus is set on the resistive behavior of the carbon nanotubes (CNTs) and the adjustability towards a defined target range. To realize the sensors on a low cost and high flexible polyethylene terephthalate (PET) foil, the intense pulsed light (IPL) sintering is introduced to achieve the required performance for both the CNT dispersion as well as the silver electrodes. The very novel topic of the simultaneous photonic sintering of a two-material layer stack and the involved challenges are demonstrated. The MWCNT dispersion was successfully printed with the inkjet printing technology and functionalized by thermal and IPL sintering methods, achieving a resistance of 100 kΩ in the target area (1 kΩ to 1 MΩ) for the sensor. The dependence of the resistance on parameters like number of CNT overprints, the pattern layout as well as the post-treatment methodology is analyzed in detail. These results can be further employed for the development of CNT-based sensor elements and the change in their resistance caused by environmental conditions. In addition, such single sensors raise the opportunity of a combination to a sensor matrix to demonstrate the integration in applications such as a shoe sole (proof of concept) but primarily for medical applications e.g., in mattresses in hospitals for constant recording of bedfast or comatose patients. © 2018 Society for Imaging Science and Technology.
In this paper, the PLA resin of Ingeo 4032D from Nature Works(USA) is selected as the research object. Linear Low Density Polyethylene (LLDPE) or EPDM rubber grafted glycidyl methacrylate (EPDM-g-GMA) is selected for PLA blend modification. At first, the mixture was granulated in an extruder and then blown to obtain various films. The mechanical properties, optical transparency, barrier properties, contact angle and printability of the polymer film were measured. The results show that through the modification, without loss of transparency, the mechanical properties, barrier properties, polarity of the surface and the adhesion of the printing code of the PLA film are improved, which is beneficial to the solution of environmental pollution caused by the undegradable of current plastic film.
This paper describes a relationship between a water content of printing paper and an equivalent thermal conductivity that affects to printing quality of printers using the heat such as laser printers and direct thermal printers. Our study targets to describe the relationship between the water content and the thermal conduction in the printing process. Especially in this report, we firstly investigated a relationship between the humidity around the paper and the change of the water content of the thermal paper. The dried thermal paper was mounted in the constant temperature and humidity chamber and the time history of the change of the paper weight was measured by using the precision balance. It is found that the water content of the thermal paper is dependent on the humidity. However, even if the humidity around the paper is changed, the water content of the paper is rapidly saturated according to the humidity. Therefore, from the viewpoint of the thermal design of the printing process, the transient change of the water content of the paper may not become important against the value of the humidity itself. In addition, the relationship between the water content of the paper and the thermal conductivity was investigated through a combination of the 1-dimensional thermal conduction experiment in the constant temperature and humidity chamber with the thermal network analysis.