With the advancement of nanomaterials and process technologies, the application fields of printed electronics have broadened. In this paper, high-resolution printing methods such as reverse offset printing and adhesion contrast planography are reviewed. In the first part, the rheology of semidry states required to achieve a single-micrometer feature by these printing methods is discussed. Together with simulations of the patterning process, the importance of elasticity and plasticity exhibited by the semidried ink layer is highlighted. By utilizing semidried ink characteristics, it is also possible to bury the conductive layer in a dielectric layer, which can significantly reduce the risk of step-coverage problems, thus making it beneficial for creating multilayered structures. In the latter part of the review, the deformation behavior of silicone rubber blankets, one of the key components in high-resolution printing, is presented. It is shown that blanket deformation has a particular peak in the vicinity of the pressed area when the blanket has a finite thickness. By optimizing the blanket structure based on contact mechanics, vertical interconnections through conformal vias can successfully be formed. A quantitative analysis on registration accuracy in relation to processing parameters such as printing pressure, tilting of roll, and the synchronization mismatch between roll and table is also presented to realize high-precision, high-resolution printed electronics.

1. Looking back on printed electronics technology, owing to the rapid progress in inkjet technology, the ink jet method in printed electronics was expected to be able to manufacture electronic circuits and semiconductor circuits very easily, as if they were for consumer use. An electronic circuit could be created with the image printed on paper by a printer.

2. The inkjet method lags other printing methods.

3. Issues with inkjet construction methods have been reported.

4. PZT type inkjet heads can be divided into several types depending on how PZT is used, and each company has its own characteristics.

5. Display applications

6. Silver nano powder is easily available in large quantities, and many companies are entering the silver nano ink market.

7. Manufacture of structures such as organic semiconductor TFTs

8. Electronic circuit embedding by laminated 3D printing

Flexible hybrid electronics (FHE) technology is a new trend in printed electronics, where mature silicon LSI devices are employed for signal processing and wireless communication circuits. This paper reviews the fundamentals and applications of FHE devices, including printing materials, printing processes, and low-temperature LSI chip mounting technology. Flexible printed sensors based on organic materials for FHE devices are briefly described. Screen printing is used to form circuit patterns, an antenna, and sensors on a flexible plastic film substrate. Thin Si-LSI chips and other components are then mounted on the printed interconnect layers using low-temperature soldering. A Bluetooth low energy (BLE) or near-field communication (NFC) system is used for data transmission. We highlight the essential steps of device fabrication. Finally, we demonstrate practical FHE devices with sensors for healthcare and logistics applications. This FHE technology can be easily applied to various sensor systems connected to a network in an IoT environment.

Printed organic photoelectric conversion devices have attracted considerable attention in recent years due to their advantages, such as potential flexibility, large-area detection, and so forth, over their inorganic counterparts. In general, narrowband applications such as industrial colorimetric measurements, and spectral biological imaging, typically use broadband photodetectors combined with additional color filters. This paper discusses the effect of device structure to realize narrow-light detection devices. Bulk heterojunction (BHJ) devices with large donor (D)/acceptor (A) interface areas exhibit a relatively high external quantum efficiency (IPCE). For BHJ devices, one of the most important factors to realize narrowband light detection is the control of charge carrier collection efficiency at the electrodes, which is attributed to the device structure, including the intrachain transport in polymers. Highly responsive polymer near-infrared devices with BHJ structures have been developed by utilizing the weak sub-bandgap absorption owing to the interface between D/A materials. We can select the absorption wavelength of the OPDs by choosing organic materials with suitable absorption wavelengths. A red-detection inverted-structure organic position sensor has also been developed using ZnO:Al as the solution-processed surface resistive layer.

With the aim of progressing toward Society 5.0, research developments in versatile light-emitting devices, which seamlessly connect us with all types of information, are rapidly being made. In this direction, devices using powder electroluminescence, which can be generated by the flat light-emission through electric field excitation, have attracted considerable attention from researchers around the world, because such devices offer excellent environmental resistance and can be fabricated using only a printing process. This paper reviews the latest research developments on powder electroluminescent devices.

Handwriting is superior in note-taking, drawing diagrams or sketches, and warm-hearted communications. We developed a handwriting ability scale to evaluate the ability to use handwriting effectively in work or daily life. This paper examines how handwriting ability affects work competency using this scale. We conducted a web questionnaire survey and analyzed 1,065 office workers' responses. The results showed that people with high handwriting abilities tended to have high competencies in various work situations and strong devotion towards their work. This indicates that we should reaffirm the importance of handwriting ability in office work.