Ndドープハイドロキシアパタイト薄膜を用いた湿度センサの特性

A Na-doped hydroxyapatite (Na-HAp) thin film was prepared on a porous Al_2O_3 substrate using a pulsed laser deposition (PLD) technique. Crystallinity and composition were evaluated by X-ray diffraction (XRD) and energy dispersive X-ray (EDX) analysis. A humidity sensor was formed by establishing an inter-digital type Au electrode on the Na-HAp film. The humidity-impedance and humidity response of impedance characteristics were measured by an LCR meter. The results indicated that the Na-HAp thin film sensor showed excellent sensitivity and responsiveness to humidity conditions. 　（和文）　パルスレーザーデポジション(PLD)法により、Ndドープハイドロキシアパタイト(Na-HAp)薄膜を多孔質Al_2O_3基板上に成膜した。薄膜の結晶性や組成はX線回折(XRD)およびエネルギー分散型蛍光X線分析(EDX)によって評価した。Na-HAp薄膜上にインターデジタル型の金電極を設けて、湿度センサとした。インピーダンスの湿度による変化と、湿度応答性をLCRメータにより測定した。その結果、薄膜センサは湿度に対して優れた感度と応答性を示した。This study was partially supported by the Project Research of the Faculty of Biology Oriented Science and Technology No.09-IV, 200

高温超伝導ナノワイヤー作製法の研究

[Abstract]A fabrication technique for high temperature superconducting (HTS) nanowires has been developed to realize photon detectors operating at high temperatures. HTS nanowires based on YBa_2Cu_3O_y (YBCO) were fabricated by electron beam (EB) lithography and Ar ion milling. During the Ar ion milling. Duuribg the Ar iron milling process, the samples were cooles by liquid N_2 to suppress degradation of YBCO due to increasing temperature. The acceleration voltage of the samples were cooled by liquid N_2 to suppress degradation of YBCO due to increasing temperature. The acceleration voltage of the Ar ions was optimized to decrease the energy of ion bombardment. To reduce the degradation from the side edge of the YBCO nanowire, a dry process using oxygen ions was employed to remove the EB resist instead of a wet process with remover and rinse solutions. A YBCO nanowire 150 nm wide and 5.4 mm long was successfully fabricated by minimizing the degradation of the YBCO film quality during the fabrication process. [要旨]液体窒素温度以上の高温領域で動作する単一光子検出器の実現を目的として, 酸化物高温超伝導ナノワイヤーの作製方法について検討を行った. 電子ビームリソグラフィーでナノパターンを形成し, Arイオンエッチングを用いて酸化物高温超伝導薄膜のYBa_2Cu_3O_yに微細加工を施すことでナノワイヤーを作製した. Arプラズマのイオン衝撃による温度上昇は超伝導特性の劣化をもたらすため, これを防ぐ目的でArイオンエッチングを行う際に液体窒素で試料の冷却を行った. これと同時に, イオソ衝撃のエネルギーを抑えるため Arイオンの加速電圧の最適化も行った. 電子ビームレジストを除去する際のリムバーやリンスなどの液体を用いたウエットプロセスによっても, YBa_2Cu_3O_yナノワイヤーの側壁部に劣化を生じるため、その対策としてOイオンを用いたドライプロセスにより電子ビームレジストの除去を行う条件を見出した. その結果, 超伝導特性に殆ど劣化のない, ワイヤー幅150nm, ワイヤー長5.4mm の酸化物高温超伝導ナノワイヤーの実現に成功した

Fabrication Scaffold with High Dimensional Control for Spheroids with Undifferentiated iPS Cell Properties

Spheroids are expected to aid the establishment of an in vitro-based cell culture system that can realistically reproduce cellular dynamics in vivo. We developed a fluoropolymer scaffold with an extracellular matrix (ECM) dot array and confirmed the possibility of mass-producing spheroids with uniform dimensions. Controlling the quality of ECM dots is important as it ensures spheroid uniformity, but issues such as pattern deviation and ECM drying persist in the conventional microstamping method. In this study, these problems were overcome via ECM dot printing using a resin mask with dot-patterned holes. For dot diameters of φ 300 μm, 400 μm, and 600 μm, the average spheroid diameters of human iPS cells (hiPSCs) were φ 260.8 μm, 292.4 μm, and 330.7 μm, respectively. The standard deviation when each average was normalized to 100 was 14.1%. A high throughput of 89.9% for colony formation rate to the number of dots and 89.3% for spheroid collection rate was achieved. The cells proliferated on ECM dots, and the colonies could be naturally detached from the scaffold without the use of enzymes, so there was almost no stimulation of the cells. Thus, the undifferentiated nature of hiPSCs was maintained until day 4. Therefore, this method is expected to be useful in drug discovery and regenerative medicine