Shinjiro Umezu

The authors focus on the Fused Deposition Modeling (FDM) 3D printer because the FDM 3D printer can print the utility resin material. It can print with low cost and therefore it is the most suitable for home 3D printer. The FDM 3D printer has the problem that it produces layer grooves on the surface of the 3D printed structure. Therefore the authors developed the 3D-Chemical Melting Finishing (3D-CMF) for removing layer grooves. In this method, a pen-style device is filled with a chemical able to

Ultralightweight and flexible power sources are essential for driving textile or wearable electronic devices and soft robots because they do not induce discomfort or limit movement when they are attached to human skin, textiles, or soft actuators. Organic solar cells (OSCs) are good candidates for developing such power sources because they have the advantages of being lightweight and flexible. However, achieving operational stability and ultrathin shape simultaneously remains difficult because t

Flexible and stable interconnections are critical for the next generation of shape-conformable and wearable electronics. These interconnections should have metal-like conductivity and sufficiently low stiffness that does not compromise the flexibility of the device; moreover, they must be achieved using low-temperature processes to prevent device damage. However, conventional interconnection bonding methods require additional adhesive layers, making it challenging to achieve these characteristic

In recent years, research on organic inorganic hybrid halide perovskite solar cells (PSCs) has surged, achieving a power conversion efficiency over 26%. Despite this progress, significant challenges hinder their commercial viability, and limited stability in typical environmental conditions, and the lack of scalable manufacturing technology for perovskite film production. This review explores various deposition techniques used in large-scale fabrication of perovskite thin-films, including electr

In this study, a new, simple, and novel oblique electrostatic inkjet (OEI) technique is developed to deposit a titanium oxide (TiO₂) compact layer (CL) on fluorine-doped tin oxide (FTO) substrate without the need for a vacuum environment for the first time. The TiO₂ is used as electron transport layers (ETL) in planar perovskite solar cells (PSCs). This bottom-up OEI technique enables the control of the surface morphology and thickness of the TiO₂ CL by simply ma

Abstract The nanopatterning of the surfaces of polymer substrates enhances the performances of photovoltaics. Ultraflexible organic photovoltaics (OPVs) are one of the promising energy harvesters for wearable electronics. A reduction in incident light angle dependence while maintaining the power conversion efficiency (PCE) is desirable for wearable electronics devices in which the angle of incident light continuously changes due to the deformation of the device. However, the nanopatterning of th

Metallized surfaces, structures are of demand by many industries, however, with the demand for materials with improved properties, cost effectiveness polymers have gained exponential attention. Thus, researchers have focused on metallization of polymers to overcome the drawbacks of polymers. Over the past few decades, the research focus has evolved from metal patterning on 2D polymer substrates to additive manufacturing-based metal patterning and metallization of 3D complex structures to build s

Human induced pluripotent stem (iPS) cell-derived cardiomyocytes are used for <i>in vitro</i> pharmacological and pathological studies worldwide. In particular, the functional assessment of cardiac tissues created from iPS cell-derived cardiomyocytes is expected to provide precise prediction of drug effects and thus streamline the process of drug development. However, the current format of electrophysiological and contractile assessment of cardiomyocytes on a rigid substrate is not appropriate f

Solar cell is one of the key technologies in this century because this has possibility to clear energy problems. We tried to pattern good titania layer of dye-sensitized solar cell (DSC) utilizing electrostatic inkjet. The electrostatic inkjet has good merit; that is ability to eject highly viscous liquid. We applied the merit for patterning titania paste on fluorine-doped tin oxide (FTO) glass. In this paper, we investigated fundamental characteristics to pattern titania layer on FTO glass beca

The precision printing of biomaterials is essential for fabricating bio devices, and two-dimensional (2D) and three-dimensional (3D) cell structures. To fabricate 3D cell structure artificially, biomaterials should be installed between cells to support the gravity force of cells. In general, the viscosity of ink from biomaterials is relatively high. An electrostatic inkjet is used for the bioprinting of cells and biomaterials because it has good merits, i.e., high printing resolution and good ca