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[Keyword] polymer(125hit)

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  • A Multi-Channel Electrochemical Measurement System for Biomolecular Detection

    Wei-Chiun LIU  Bin-Da LIU  Chia-Ling WEI  

     
    PAPER-Electronic Circuits

      Vol:
    E99-C No:11
      Page(s):
    1295-1303

    A modularized, low-cost, and non-invasive electrochemical examination platform is proposed in this work. Melatonin has been found to be a possible significant indicator molecule in the detection of breast cancer. 3-hydroxyanthranilic acid and nuclear matrix protein 22 can be used as a significant index for potential bladder cancer risks. The proposed system was verified by measuring the melatonin, 3-hydroxyanthranilic acid and nuclear matrix protein 22. Cyclic voltammetry and molecularly imprinted polymers were used in the experiments. Screen-printed electrodes were coated with a film imprinted with target molecules. The measurement results of the proposed system were compared with those of a commercial potentiostat. The two sets of results were very similar. Moreover, the proposed system can be expanded to a four-channel system, which can perform four measurements simultaneously. The proposed system also provides convenient graphical user interface for real-time monitoring and records the information of the redox reactions.

  • Control of Morphology and Alignment of Liquid Crystal Droplets in Molecular-Aligned Polymer for Substrate-Free Displays Open Access

    Daisuke SASAKI  Yosei SHIBATA  Takahiro ISHINABE  Hideo FUJIKAKE  

     
    INVITED PAPER

      Vol:
    E99-C No:11
      Page(s):
    1234-1239

    We have proposed composite films composed of a molecular-aligned polymer and liquid crystal (LC) for substrate-free liquid crystal displays with high-contrast images. We successfully controlled the molecular alignment of the LC and formed molecular-aligned LC droplets in the polymer by controlling the fluidity of the LC/monomer mixture and the curing rate of the monomer.

  • Millimeter-Wave Broadband Mode Transition between Grounded Coplanar Waveguide and Post-Wall Waveguide

    Ryohei HOSONO  Yusuke UEMICHI  Xu HAN  Ning GUAN  Yusuke NAKATANI  

     
    PAPER-Antennas and Propagation

      Vol:
    E99-B No:1
      Page(s):
    33-39

    A broadband mode transition between grounded coplanar waveguide (GCPW) and post-wall waveguide (PWW) is proposed. The transition is composed of GCPW, microstrip line (MSL) and PWW, where the GCPW and PWW are connected via the MSL. The transition is fabricated on liquid crystal polymer (LCP) substrate because of its low dielectric loss and cost effectiveness based on a roll-to-roll fabrication process. Center strip of the GCPW is sandwiched by two ground pads in each of which two through-holes and a rectangular slit are structured. Broadband impedance matching is achieved by this structure thanks to an addition of lumped inductance and capacitance to the transition. A part of the MSL is tapered for the broadband operation. A 25% impedance bandwidth for |S11| less than -15dB is achieved in measurement of a fabricated transition. Loss of the GCPW ground-signal-ground (GSG) pad of 0.12dB and that of the MSL-PWW transition of 0.29dB at 60GHz are evaluated from the measurement. Fabrication error and the caused tolerance on performance are also evaluated and small variation in production is confirmed. The mode transition can be used for low loss antenna-in-package in millimeter-wave applications.

  • Flexible Polymer-Wall-Stabilized Blue-Phase Liquid Crystal Cell Using Plastic Substrates

    Hideki SAKAI  Takahiro ISHINABE  Hideo FUJIKAKE  

     
    BRIEF PAPER

      Vol:
    E98-C No:11
      Page(s):
    1043-1046

    To develop a flexible liquid crystal display (LCD) with a wide viewing angle range and high contrast ratio, we have proposed a flexible blue-phase LC device sustained by polymer walls inside the LC cell. We clarified that the polymer walls can maintain a constant cell gap and suppress the generation of alignment defects of the blue-phase LC in a bending state.

  • Thermal Annealing Effect on Optical Absorption Spectra of Poly(3-hexylthiophene):Unmodified-C60 Composites

    Kazuya TADA  

     
    BRIEF PAPER

      Vol:
    E98-C No:2
      Page(s):
    120-122

    The combination of a halogen-free solvent 1,2,4-trimethylbenzene and unmodified fullerene potentially provides a way to develop environmentally-friendly and cost-effective solution-processed organic photocells. In this paper, the thermal annealing effect on the optical absorption spectra in poly(3-hexylthiophene):unmodified-C$_{60}$ composites with various compositions is reported. It is found that the onset temperature of the absorption spectrum change is higher in the composites with higher fullerene content. It is speculated that strong interaction between the polymer main chain and C$_{60}$ tends to suppress the reorientation of polymer main chains in a composite with high C$_{60}$ content.

  • Synthesis and Structural Properties in a Film State of Ladder-type Polydiacetylene with a Terephthalamide Linker for Organic Semi-conducting Application

    Yuuki MIYAZAKI  Kazuo OKAMOTO  Kenji OGINO  

     
    BRIEF PAPER

      Vol:
    E98-C No:2
      Page(s):
    116-119

    The novel ladder-shaped polydiacetylene with a terephthalamide linker in the molecular center, namely poly(TPh-bisDA) was synthesized by photo-polymerization. The characteristics of thin films of polymer were dependent upon a casting solvent, but no significant change of backbone conformation of the PDA was observed. Obtained film is expected to be applied to the semi-conducting materials for organic field effect transistors (OFET).

  • Vapor Deposition Polymerization of Polyimide with Naphthalene Unit

    Ryosuke KIKUCHI  Satoshi USUI  Kuniaki TANAKA  Hiroaki USUI  

     
    BRIEF PAPER

      Vol:
    E98-C No:2
      Page(s):
    129-132

    Polyimide thin films were prepared by vapor-deposition polymerization. Naphthalene carboxylic dianhydride (NTCDA) was coevaporated with either diamino naphthalene (DAN) or diamino benzophenone (DAB). Coevaporation of dianhydride and diamines yielded thin films of polyamic acids. A polyimide thin film was obtained by annealing the codeposited film of NTCDA-DAB. On the other hand, the codeposited film of NTCDA-DAN was not imidized by annealing. In both cases, chemical structures of the products were not largely influenced by the molar ratio of depositing monomers if sufficient amount of diamine molecules are supplied in the coevaporation process.

  • Fabrication of Nanosized Structures on Nafion Membranes by Thermal Nanoimprinting

    Nobuya HIROSHIBA  Wataru YANO  Ryuji OKUMURA  Yo ICHIKAWA  

     
    BRIEF PAPER

      Vol:
    E98-C No:2
      Page(s):
    133-135

    We demonstrated a novel technique to fabricate nanosized structures on a Nafion membrane, using thermal nanoimprinting with alinebreak $5 imes 5$,$mu $m$^{mathrm{2}}$ square pattern Si mold without any polymer damage. A 24,MPa thermal imprinting pressure was used for 10,min. We observed high aspect ratio ($sim$1:10) pillars on the surface after imprinting at 200$^{circ}$C. Finally, we used a novel quartz mold with a 200,nm resolution dot pattern.

  • Influence of Polymer Gate Dielectrics on p-Channel and n-Channel Formation of Fluorene-type Polymer Light-emitting Transistors

    Hirotake KAJII  Masato ISE  Hitoshi TANAKA  Takahiro OHTOMO  Yutaka OHMORI  

     
    BRIEF PAPER

      Vol:
    E98-C No:2
      Page(s):
    139-142

    The effects of the gate dielectrics on ambipolar transport in top-gate-type polymer light-emitting transistors with single-layer and bilayer gate dielectrics are investigated. Hole field-effect mobility is dependent on the dielectric constant of the gate dielectric onto the active layer. Hole transport of devices is affected by the dipolar disorder in the first gate dielectric layer on the active layer. Electron threshold voltage tends to decrease with increasing the total stacked gate capacitance.

  • Usefulness of Transmission Ellipsometric Method for Evaluation of Electro-optic Materials

    Toshiki YAMADA  Akira OTOMO  

     
    BRIEF PAPER

      Vol:
    E98-C No:2
      Page(s):
    143-146

    A transmission ellipsometric method without an aperture was recently developed to characterize the electro-optic (EO) performance of EO polymers. The method permits much simpler optical setup compared to the reflection method, and allows easy performance of the incident angle dependence measurements using a conventional glass substrate and uncollimated beam. This paper shows the usefulness of this method for a simple and reliable evaluation of the EO coefficient both for organic and inorganic EO materials, as well as analysis for uniaxial anisotropic materials.

  • Thickness of Crystalline Layer of Rubbed Polyimide Film Characterized by Grazing Incidence X-ray Diffractions with Multi Incident Angles

    Ichiro HIROSAWA  Tomoyuki KOGANEZAWA  Hidenori ISHII  

     
    BRIEF PAPER

      Vol:
    E97-C No:11
      Page(s):
    1089-1092

    Thickness of crystalline layer induced by annealing after rubbing at surface of polyimide film for liquid crystal displays was estimated to be 3--5 nm by grazing-incidence X-ray diffractions with multi incident angles. Agreement of thickness of crystalline layer with that of initially oriented layer suggests polymer orientation induced by rubbing proceeds crystallization by annealing. Furthermore, no in-plane smectic ordering in bottom 20,nm region of polyimide film was suggested.

  • A Simple Through-Hole Based Transformer between Microstrip Line and Post-Wall Waveguide for Millimeter-Wave Applications

    Yusuke UEMICHI  Ryouhei HOSONO  Ning GUAN  Jiro HIROKAWA  Makoto ANDO  

     
    PAPER

      Vol:
    E97-C No:10
      Page(s):
    941-947

    We proposed a through-hole based transformer between microstrip line and post-wall waveguide (PWW). The transformer is based on a through-hole which is electrically separated from top and bottom broad walls of a waveguide by ring-shaped spaces. The proposed transformer shows a considerable merit compared with a conventional one based on blind-via in terms of fabrication and cost because it can be realized by through-holes in general printed-circuit-board technology. We selected liquid crystal polymer (LCP) as the material of substrates because of its lower dielectric loss and easy fabrication. The transformer was fabricated and measured. The loss associated with the mode conversion is estimated to be around 0.32,dB, and the bandwidth for a reflection smaller than $-15$,dB is 8,GHz, i.e., from 59 to 67,GHz.

  • Amperometric Biosensor with Composites of Carbon Nanotube, Hexaamineruthenium(III)chloride, and Plasma-Polymerized Film

    Tatsuya HOSHINO  Takahiro INOUE  Hitoshi MUGURUMA  

     
    PAPER-Organic Molecular Electronics

      Vol:
    E96-C No:12
      Page(s):
    1536-1540

    A novel fabrication approach for the amperometric biosensor composed of carbon nanotubes (CNT), a plasma-polymerized film (PPF), hexamineruthenium(III)chloride (RU), and enzyme glucose oxidase (GOD) is reported. The configuration of the electrochemical electrode is multilayer films which contain sputtered gold, lower acetonitrile PPF, CNT, RU, GOD, and upper acetonitrile PPF, sequentially. First, PPF deposited on Au acts as a permselective membrane and as a scaffold for CNT layer formation. Second, PPF directly deposited on GOD acts as a matrix for enzyme immobilization. To facilitate the electrochemical communication between the CNT layer and GOD, CNT was treated with nitrogen plasma. The electron transfer mediator RU play a role as the mediator, in which the electron caused by enzymatic reaction transports to the electrode. The synergy between the electron transfer mediator and CNT provides benefits in terms of lowering the operational potential and enhancing the sensitivity (current). The optimized glucose biosensor revealed a sensitivity of 3.4µA mM-1 cm-2 at +0.4V vs. Ag/AgCl, linear dynamic range of 2.5-19mM, and a response time of 6s.

  • Nonvolatile Polymer Memory-Cell Embedded with Ni Nanocrystals Surrounded by NiO in Polystyrene

    HyunMin SEUNG  Jong-Dae LEE  Chang-Hwan KIM  Jea-Gun PARK  

     
    BRIEF PAPER

      Vol:
    E96-C No:5
      Page(s):
    699-701

    In summary, we successfully fabricated the nonvolatile hybrid polymer 4F2 memory-cell. It was based on bistable state, which was observed in PS layer that is containing a Ni nanocrystals capped with NiO tunneling barrier sandwiched by Al electrodes. The current conduction mechanism for polymer memory-cell was demonstrated by fitting the I-V curves. The electrons were charged and discharged on Ni nanocrystals by tunneling through the NiO tunneling barrier. In addition, the memory-cell showed a good and reproducible nonvolatile memory-cell characteristic. Its memory margin is about 1.410. The retention-time is more than 105 seconds and the endurance cycles of program-and-erase is more than 250 cycles. Furthermore, Thefore, polymer memory-cell would be good candidates for nonvolatile 4F2 cross-bar memory-cell.

  • Temporal Change in Electric Potential Distribution and Film Thickness in Electrophoretic Deposition of Conjugated Polymer

    Kazuya TADA  

     
    BRIEF PAPER

      Vol:
    E96-C No:3
      Page(s):
    378-380

    It has been reported that the temporal change of current during the deposition shows a plateau and a break, similar to those found in a photocurrent profile taken by the time-of-flight technique for the investigation of photocarrier dynamics in condensed matters, enabling the estimation of electrophoretic mobility of colloidal particles in the suspension. The estimation of the electrophoretic mobility from transient current during the deposition by the simple drift model is based on the assumption that a constant electric field is uniformly applied between the positive and negative electrodes. Therefore, it is important to check if this assumption is satisfied. It is also important to measure the temporal evolution of film thickness, because this may give information about uniformity of colloidal size in the suspension. This study addresses these topics and validity of the assumption is confirmed.

  • Improvement of Adhesion Strength of Fluoropolymer Thin Films by Vapor Deposition Polymerization

    Kazuo SENDA  Tsuyoshi MATSUDA  Kuniaki TANAKA  Hiroaki USUI  

     
    BRIEF PAPER

      Vol:
    E96-C No:3
      Page(s):
    374-377

    Fluoropolymer thin films were prepared by the ion-assisted vapor deposition polymerization (IAD) of 2-(perfluorohexyl)ethylacrylate (Rf-6). The adhesion strength of the film to substrates was estimated by sonicating the films in water and by immersing the films into dichloro-pentafluoro propane (HCFC225). The Rf-6 polymer films by IAD showed stronger adhesion to glass compared to a spin-coated Teflon AF film. The adhesion strength was improved with increasing ion energy Eion of IAD. The IAD films showed superior adhesion to PET surface compared to the glass substrate. The Rf-6 polymer film was effective as a single-layer antireflective coating. The refractive index of the film was 1.368 (λ = 546 nm), which increased slightly with increasing Eion. IAD can be a promising method to prepare fluoropolymer thin films due to the solvent-less process and the flexibility in controlling the film characteristics by the ion energy.

  • NADH Sensing Using Neutral Red Functionalized Carbon Nanotube/Plasma-Polymerized Film Composite Electrode

    Tatsuya HOSHINO  Hitoshi MUGURUMA  

     
    BRIEF PAPER-Organic Molecular Electronics

      Vol:
    E95-C No:7
      Page(s):
    1300-1303

    A novel fabrication approach for electrochemical sensing of nicotinamide adenine dinucleotide (NADH) using neutral red (NR) functinalized carbon nanotube/plasma-polymerized film composite electrode is reported. The configuration of sensing electrode was NR-functionalized CNTs sandwiched between two acetonitrile PPFs on sputtered gold thin film. The NR as an electron transfer mediator shuttles the electron from the CNT to gold electrode. Due to the synergistic effect between NR and CNT, the resulting electrode showed the lower detection potential and the larger sensitivity (current) than that of NR or CNT alone. The sensor revealed a sensitivity of 29 µA mM-1 cm-2 at +0.15 V vs. Ag/AgCl, linear dynamic range of 0.08–4.2 mM, a detection limit of 18 µM at S/N=3, and a response time of 7 s.

  • Fabrication and Characterization of Ferroelectric Poly(Vinylidene Fluoride–Trifluoroethylene) (P(VDF-TrFE)) Thin Film on Flexible Substrate by Detach-and-Transferring

    Woo Young KIM  Hee Chul LEE  

     
    PAPER

      Vol:
    E95-C No:5
      Page(s):
    860-864

    In this paper, a 60 nm-thick ferroelectric film of poly(vinylidene fluoride–trifluoroethylene) on a flexible substrate of aluminum foil was fabricated and characterized. Compared to pristine silicon wafer, Al-foil has very large root-mean-square (RMS) roughness, thus presenting challenges for the fabrication of flat and uniform electronic devices on such a rough substrate. In particular, RMS roughness affects the leakage current of dielectrics, the uniformity of devices, and the switching time in ferroelectrics. To avoid these kinds of problems, a new thin film fabrication method adopting a detach-and-transfer technique has been developed. Here, 'detach' means that the ferroelectric film is detached from a flat substrate (sacrificial substrate), and 'transfer' refers to the process of the detached film being moved onto the rough substrate (main substrate). To characterize the dielectric property of the transferred film, polarization and voltage relationships were measured, and the results showed that a hysteresis loop could be obtained with low leakage current.

  • Loss Characteristics of Polymer Waveguide Fabricated by UV Laser Drawing of an Optically-Sensitive Hybrid Silicone

    Soichi KOBAYASHI  Seigi OKI  Takahiro ISHIKURA  Keisuke KATO  Toshihiro SUDA  

     
    BRIEF PAPER

      Vol:
    E94-C No:12
      Page(s):
    1858-1860

    Polymer multimode optical waveguides were fabricated from optically-sensitive hybrid silicone using the ultraviolet laser drawing method. The waveguide loss values were measured as 0.069 dB/cm with a laser diode, 0.069 dB/cm with a vertical-cavity surface-emitting laser, and 0.128 dB/cm with a light-emitting diode. The cross waveguide on a curved waveguide was drawn by overlapped direct laser drawing. The crosstalk and excess loss at the cross angle of 50 in the cross waveguide were measured as 47 dB and 0.5 dB, respectively.

  • Frequency Characteristics of Polymer Field-Effect Transistors with Self-Aligned Electrodes Investigated by Impedance Spectroscopy Open Access

    Hideyuki HATTA  Takashi NAGASE  Takashi KOBAYASHI  Mitsuru WATANABE  Kimihiro MATSUKAWA  Shuichi MURAKAMI  Hiroyoshi NAITO  

     
    INVITED PAPER

      Vol:
    E94-C No:11
      Page(s):
    1727-1732

    Solution-based organic field-effect transistors (OFETs) with low parasitic capacitance have been fabricated using a self-aligned method. The self-aligned processes using a cross-linking polymer gate insulator allow fabricating electrically stable polymer OFETs with small overlap area between the source-drain electrodes and the gate electrode, whose frequency characteristics have been investigated by impedance spectroscopy (IS). The IS of polymer OFETs with self-aligned electrodes reveals frequency-dependent channel formation process and the frequency response in FET structure.

21-40hit(125hit)