This article reports briefly on flexible and printed organic electronics, with an emphasis on organic thin-film transistor (OTFT) device technology, and highlights our laboratory's latest research and development results. Progress will be described in areas including printing processes, printable materials and printed devices, as well as potential applications. Printed OTFT devices are fabricated with various printing methods and silver nanoparticle inks are commonly used to form interconnects and electrodes. Small-molecule organic semiconductors with their highly crystalline nature are patterned on printed source and drain electrodes. A typical carrier mobility for printed OTFT devices is over 1cm2/Vs at low operating voltages, even for short channel length devices. Integrated circuits such as D-flip flops and ring oscillators as well as operational amplifiers are successfully demonstrated. An OTFT-based biosensor with an extended gate electrode for bio-sensing is proposed and good sensitivities are obtained for the detection of immunoglobulins, lactate and other biomarkers. Lastly, flexible hybrid sensors with Si-LSI die are also demonstrated and their applications are discussed.
Flexible printed electronics is of great interest in the next class of device platform to detect multiple information from macroscale non-planar surfaces. As a contribution to this field, in this review, printed flexible sensors and their applications are introduced. Especially, strain, temperature, electrocardiogram, and ultraviolet light sensors on flexible sheets are discussed based on experimental results. Furthermore, by arranging the device structures and integrating the sensors, electronic skin/whisker and healthcare patch applications are demonstrated as the first proof-of-concepts. Although there are still a lot of challenges such as stability, reliability, and more functionalities for a variety of applications to move forward to realizing practical printed electronics, these developments may be able to help the future progress for flexible printed electronics. This review follows these to guide the readers to develop the system further.
OLED attracts attention as next-generation display technologies, and products manufactured by the vacuum deposition method are already penetrating the market. Digital fabrication, which manufactures this OLED display using inkjet, is a key technology that significantly reduces manufacturing costs.
In this paper, the structure of the OLED display is explained, and the features of the technology and products are stated. The features of several manufacturing methods of OLED display are explained.
Striped light emission unevenness due to variation in ink amount which was a problem of the inkjet method was solved by new techniques. As a result, OLED displays manufactured by the inkjet method have become available. An ink jet apparatus capable of massively manufacturing a large-sized OLED display at a low cost is nearing practical use. It is expected that the spread of OLED display will accelerate.
Printed electronics is technology for manufacturing electronic circuits, sensors and elements by applying coating and printing technology. Typical devices of printed electronics are biosensors, RFID tags, Organic EL lighting, Flexible displays, and so on. In the USA, a social structure called “Trillion Sensors Universe “ is advocated and a so-called “flexible device” is in high demand. These are multiple layered electronics devices on flexible substrates. But the distortion characteristic of flexible substrates such as film makes it difficult to form layered circuits by photolithography or other mask-based methods. Toray Engineering have developed a technology that uses inkjet technology to form layered circuit pattern corresponding to the TFT array on flexible film.
3D printing has been around for several decades, however using specialty additive manufacturing printers to make fully functional electronics circuits is new. The breakthrough in developing electronics with 3D printers comes from Nano Dimension, the Israel-based creators of the DragonFly 2020 Pro 3D Printer, which is designed for the production of professional multilayer printed circuit boards (PCBs) and 3D circuitry. Already, companies are using this 3D printer for PCB prototyping and development, and just like other forms of 3D printing, this latest advancement brings new levels of efficiency and productivity to support increased innovation and generate new revenue streams. With the DragonFly 2020 Pro 3D printer, manufacturers and designers can protect their intellectual property and enjoy faster times to market because they no longer need to use outside outsourcing facilities;product development costs are lowered because designs can be modified and reprinted on the fly;and design flexibility and quality are vastly improved.
Reviewing printing technology in the field of electronics products and printed electronics by showing several examples to understand the printing technology's contribution in the past, International Standardization of Printed electronics in IEC/TC 119 is explained mainly by their activities from the view point of each WG's mission, also explained their published standards by introducing specific recent examples, especially in the field of conductive inks. And finally, in discussing the printed electronics of the standard, some basic concept of printing and sense of micro-contact printing are pointed out to be still devoid, but bright prospects for the future are commented.
Iupizeta® EP (Environmental Protection Process Polycarbonate) is the specialty Polycarbonate resin that delivers the Highest refractive index for compact high-resolution Camera lenses. We created the Iupizeta® EP resin that has both unique characteristics of high refractive index which bring higher pixel and ultra low birefringence which effect a reduction of blurring, with microscopic design of materials. This resin has already been installed in various cameras-mainly Smartphone cameras-as lenses since the sale in 2008, and it also contributes to the increase of the number of pixels, the improvement of the performance, furthermore the liberalization of the camera design. In the future, we are also expected to find use in automotive systems, security cameras, and advanced devices such as medical field.