研究者詳細 - 髙嶋　一登

その他リンク： https://www.jstage.jst.go.jp/article/jbse/20/1/20_24-00230/_pdf/-char/en

Effect of R-phase on shape recovery speed of Ti-Ni shape memory alloy wire for variable-stiffness mechanism using jamming transition phenomenon 査読有り国際誌

MATSUMOTO Naoki, CHO Hiroki, TAKASHIMA Kazuto, SUZUKI Hidetaka

Mechanical Engineering Journal ( 一般社団法人日本機械学会 ) 11 ( 5 ) 24-00130 - 24-00130 24-00130 (10pp) 2024年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

The jamming transition phenomenon refers to the change in stiffness of a powder as its density changes. As a familiar example, vacuum-packed coffee grounds are hard, but when opened to allow air into the package and the density is reduced, the grounds become softer. Using Ti-Ni shape memory alloys (SMAs) and the jamming transition phenomenon, a variable-stiffness and deformable link was devised and prototyped by Takashima et al. (2022). Although the mechanism worked well, it operated slowly due to the slow shape recovery velocity of the SMA. For practical application of this mechanism, it is necessary to improve the recovery velocity of Ti-Ni SMA. Normally, Ti-Ni SMAs exhibit an austenite to martensite phase transformation; however, Miyazaki and Otsuka (1984) observed that under some conditions, R-phase transformation can occur between these phase transformations. In a previous study, Tanikata et al. (2022) observed that SMAs that show R-phase transformation during shape recovery tend to have higher recovery stress than SMAs that do not show R-phase transformation. Therefore, SMAs that show R-phase transformation during shape recovery are expected to have a high shape recovery velocity. This study investigates the effect of R-phase transformation on the recovery velocity of SMA. From the experimental results, specimens that show R-phase transformation tend to have a higher recovery velocity than specimens that do not show R-phase transformation. However, the mechanism created using materials showing R-phase transformation had a small amount of shape recovery during shape recovery. Thus, we attempted to improve the mechanical properties of the SMA by training. The device using the trained specimen demonstrated increased shape recovery compared to the device using the untrained specimen.

DOI： 10.1299/mej.24-00130

その他リンク： https://www.jstage.jst.go.jp/article/mej/11/6/11_24-00130/_pdf/-char/en

Structural Modification of Catheter-Type Tactile Sensor Using Polyvinylidene Fluoride (PVDF) Film 査読有り国際誌

S. Nagano, K. Takashima, M. Watanabe, K. Ishida

Twenty-first International Conference on Flow Dynamics (ICFD2024) 677 - 679 2024年11月

Structural modification and application of variable sensitivity force sensors fabricated using shape-memory polymer 査読有り国際誌

T. Taniguchi, K. Takashima

Proceedings of SICE Festival 2024 with Annual Conference 272 - 277 2024年08月

Characterization of Catheter-Type Tactile Sensor Using Polyvinylidene Fluoride (PVDF) Film 査読有り国際誌

Takashima Kazuto, Nagano Souichiro, Watanabe Masahiro, Ishida Kenji

Journal of Robotics and Mechatronics ( 富士技術出版株式会社 ) 36 ( 4 ) 899 - 908 2024年08月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

To enable quantitative palpation in vivo, we previously developed a catheter-type tactile sensor with an outer diameter of 2 mm composed of a polyvinylidene fluoride (PVDF) film for minimally invasive surgery. However, our previous studies did not evaluate the effect of the PVDF film shape on the sensor output. In this study, we fabricated three types of prototype sensors with different PVDF film shapes and sizes using a simple cutting method. One of the films had the same shape as that used in one of our previous studies. We also prepared two types of PVDF film with a wide base and a narrow tip because we assumed that the deformation of the sensor gradually decreases from the root to the tip, similar to the first mode of the natural frequency. We evaluated the frequency response of the proposed sensors by vibrating the sensor tip and compared the results with the theoretical values. It was confirmed that the sensor output increased with PVDF film size. Although this tendency was observed for both the measured and theoretical values, the measured values were smaller than the theoretical values. Moreover, the effect of film size was larger than that of film shape. Improvements in the sensor structure and the theoretical equation and better evaluation methods are required in order to optimize the film shape and size.

DOI： 10.20965/jrm.2024.p0899

その他リンク： http://id.ndl.go.jp/bib/033646324

Development and Application of Shape-Memory Polymer and Alloy Composite Sheets 査読有り国際誌

Takashima Kazuto, Okamura Yuta, Nagaishi Junya, Cho Hiroki, Noritsugu Toshiro, Mukai Toshiharu

Journal of Robotics and Mechatronics ( 富士技術出版株式会社 ) 36 ( 3 ) 769 - 778 2024年06月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

The authors previously developed a flexible and multi-degree-of-freedom pneumatic artificial rubber muscle that uses shape-memory polymer (SMP) sheets with an embedded electrical heating wire. The bending direction and initial shape of the muscle can be changed by utilizing the large difference in the elastic modulus below and above the glass transition temperature, shape fixity, and shape recovery of SMPs. In this study, to improve performance, we propose a shape-memory composite (SMC) sheet that consists of SMP sheets with an embedded shape-memory alloy (SMA) wire used as an electric heating wire. The mechanical properties of the previously developed SMP sheets and the proposed SMC sheets are compared through shape recovery, bending, and tensile tests using prototypes. The motion of the artificial muscle with various samples attached is evaluated through an isometric test and bending angle measurements. The experimental results confirm that the use of the SMA wire improves the production reproducibility and shape recovery of the SMP sheets without degrading other mechanical properties or actuator performance.

DOI： 10.20965/jrm.2024.p0769

その他リンク： http://id.ndl.go.jp/bib/033548082

High-Density, Nonvolatile, Flexible Multilevel Organic Memristor Using Multilayered Polymer Semiconductors 査読有り国際誌

Sharma S., Pandey M., Nagamatsu S., Tanaka H., Takashima K., Nakamura M., Pandey S.S.

ACS Applied Materials and Interfaces 16 ( 17 ) 22282 - 22293 2024年04月

記述言語：英語掲載種別：研究論文（学術雑誌）

Nonvolatile organic memristors have emerged as promising candidates for next-generation electronics, emphasizing the need for vertical device fabrication to attain a high density. Herein, we present a comprehensive investigation of high-performance organic memristors, fabricated in crossbar architecture with PTB7/Al-AlOx-nanocluster/PTB7 embedded between Al electrodes. PTB7 films were fabricated using the Unidirectional Floating Film Transfer Method, enabling independent uniform film fabrication in the Layer-by-Layer (LbL) configuration without disturbing underlying films. We examined the charge transport mechanism of our memristors using the Hubbard model highlighting the role of Al-AlOx-nanoclusters in switching-on the devices, due to the accumulation of bipolarons in the semiconducting layer. By varying the number of LbL films in the device architecture, the resistance of resistive states was systematically altered, enabling the fabrication of novel multilevel memristors. These multilevel devices exhibited excellent performance metrics, including enhanced memory density, high on-off ratio (>108), remarkable memory retention (>105 s), high endurance (87 on-off cycles), and rapid switching (∼100 ns). Furthermore, flexible memristors were fabricated, demonstrating consistent performance even under bending conditions, with a radius of 2.78 mm for >104 bending cycles. This study not only demonstrates the fundamental understanding of charge transport in organic memristors but also introduces novel device architectures with significant implications for high-density flexible applications.

DOI： 10.1021/acsami.4c03111

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85191165281&origin=inward

Methods for evaluating friction between intravascular device and vascular biomodel 査読有り国際誌

K. Takashima, M. Ohta, K. Yoshinaka, T. Washio, K. Chinzei

Tribology Online ( 一般社団法人日本トライボロジー学会 ) 19 ( 1 ) 42 - 54 2024年02月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：記事・総説・解説・論説等（学術雑誌）

In recent years, endovascular treatments, in which a treatment device such as a catheter is inserted into a blood vessel to directly approach a lesion, have become increasingly popular worldwide. For safer treatment and further optimization of medical devices, a deeper understanding of the vascular biotribology of the medical devices, biomodels, and blood vessels and an appropriate evaluation method are required. This review paper presents the current state of research on the evaluation of the friction between an intravascular device and a vascular biomodel. We review the experimental conditions, including the sample shape, sliding speed, contact pressure, lubricant, materials, and temperature. Standardized methods should be established for evaluating the friction between an intravascular device and a vascular biomodel.

DOI： 10.2474/trol.19.42

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85186755450&origin=inward

Motion evaluation of variable-stiffness link based on shape-memory alloy and jamming transition phenomenon 査読有り国際誌

K. Takashima, H. Suzuki, T. Imazawa, H. Cho

Journal of Robotics and Mechatronics ( 富士技術出版株式会社 ) 36 ( 1 ) 181 - 189 2024年02月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

In rapidly aging societies, the application of robots has spread from industry to nursing and social welfare. As the designs of industrial and non-industrial robots are different, numerous robot components with various shapes and stiffness are required for different tasks. In this study, we attached a variable-stiffness link based on a shape-memory alloy (SMA) and the jamming transition phenomenon to a robot arm and evaluated its pick-and-place motion for various objects with different shapes and weights. The link can be fixed in an arbitrary shape and then restored to its initial shape via the shape memory effect. The objects were picked up and moved by a prototype link, which consisted of four SMA wires inserted in the jamming mechanism. We compared two states of the link, namely with and without deformation of the link into a shape (the cen-terline and the cross section) to suit the target object using a mold. Experiments confirmed that changing and fixing the link shape to suit the target object increased both positioning accuracy and weight capacity.

DOI： 10.20965/jrm.2024.p0181

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85185676295&origin=inward

Enhancement in Capacitance of Ionic Type of EAP-Based Strain Sensors 査読有り国際誌

Singh N.K., Takashima K., Pandey S.S.

Sensors 23 ( 23 ) 2023年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

This paper aims to enhance the capacitance of electroactive polymer (EAP)-based strain sensors. The enhancement in capacitance was achieved by using a free-standing stretchable polymer film while introducing conducting polymer to fabricate a hybrid dielectric film with controlled conductivity. In this work, styrene-ethylene-butylene-styrene (SEBS) rubber was used as the base material, and dodecyl benzene sulfonate anion (DBSA)-doped polyaniline (PANI) was used as filler to fabricate a hybrid composite conducting film. The maleic anhydride group of the SEBS Rubber and DBSA, the anion of the polyaniline dopant, make a very stable dispersion in Toluene and form a free-standing stretchable film by solution casting. DBSA-doped polyaniline increased the conductivity and dielectric constant of the dielectric film, resulting in a significant enhancement in the capacitance of the EAP-based strain sensor. The sensor presented in this article exhibits capacitance values ranging from 24.7 to 100 µF for strain levels ranging from 0 to 100%, and sensitivity was measured 3 at 100% strain level.

DOI： 10.3390/s23239400

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85179135949&origin=inward

Effect of R-phase on shape recovery speed of Ti-Ni shape memory alloy wire for variable-stiffness mechanism using jamming transition phenomenon 査読有り国際誌

N. Matsumoto, H. Cho, K. Takashima

Proceeding of The Advanced Technology in Experimental Mechanics and International DIC Society Joint Conference 2023 (ATEM-iDICs '23) 2023年10月

Improvement of Electrical Heating Wire Structure of Force Sensors Using Shape-Memory Polymer 査読有り国際誌

T. Taniguchi, K. Takashima

Proceedings of SICE Annual Conference 2023 588 - 593 2023年09月

担当区分：責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Japan Tsu 2023年09月06日 - 2023年09月09日

We previously developed a variable-sensitivity force sensor that uses a cantilever made of a shape-memory polymer (SMP) sheet with an embedded electrical heating wire, the stiffness of which varies according to temperature. In this study, we improve the structure of the heating wire using computer numerical control machining. Furthermore, we fabricate an SMP force sensor with a beam fixed at both ends. Experiments using prototypes of the original and improved sensors demonstrate that the temperature distribution of the heated SMP sheet and the distance between the electrical heating wires are uniform. Moreover, we confirm that for both prototype sensors, the relationship between strain and force depends on temperature.

DOI： 10.23919/SICE59929.2023.10354188

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85182596805&origin=inward

Improved Method of Preparation for Shape-memory Polymer Sheet with Embedded Electrical Heating Wire for Use in Pneumatic Artificial Rubber Muscle 査読有り国際誌

Y. Okamura, K. Takashima, T. Noritsugu, T. Mukai

Proceedings of SICE Annual Conference 2023 582 - 587 2023年09月

担当区分：責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Japan Tsu 2023年09月06日 - 2023年09月09日

We improved the structure of a shape-memory polymer (SMP) sheet with an embedded electrical heating wire, thus enhancing the manufacturing reproducibility and durability of flexible and multi-degree-of-freedom pneumatic artificial rubber muscles. We prepared two types of SMP sheets using the previous and improved methods and compared the mechanical properties via bending and tensile tests. The SMP sheets were then attached to a pneumatic artificial rubber muscle, and subjected to a bending angle test and an isometric test to evaluate their bending properties.

DOI： 10.23919/SICE59929.2023.10354241

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85182598520&origin=inward

Development of pneumatic artificial rubber muscle using segmented shape-memory polymer sheets 査読有り国際誌

K. Takashima, Y. Okamura, D. Iwamoto, T. Noritsugu, T. Mukai

Journal of Robotics and Mechatronics ( 富士技術出版株式会社 ) 35 ( 1 ) 113 - 124 2023年02月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

We have developed a pneumatic artificial rubber muscle using two shape-memory polymer (SMP) sheets. We attached the SMP sheets to a linear pneumatic artificial rubber muscle. Utilizing the large difference in the elastic modulus below and above the glass transition temperature, the shape fixity and shape recovery of SMPs, the bending direction and the initial shape can be changed. In this study, in order to increase the bending motion range, we developed a segmented SMP sheet with embedded electrical heating wires, and evaluated its mechanical properties using bending and tensile tests. Moreover, we attached such sheets to an artificial muscle and evaluated the bending motion. Bending tests showed that segmenting the SMP sheets greatly reduced their bending stiffness. In tensile tests at temperatures below the glass transition temperature, it was found that the artificial muscle with the attached sheet withstood high elongating loads without failure. Attachment of such segmented SMP sheets to an artificial muscle resulted in an increased bending angle. Through isotonic and isometric tests, we showed that the prototype actuator could bend in two directions.

DOI： 10.20965/jrm.2023.p0113

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85148859459&origin=inward

Variable-sensitivity force sensor based on structural modification 査読有り国際誌

K. Takashima, K. Ota, H. Cho

Sensors 23 ( 4 ) 2077 (15pp) 2023年02月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

Force sensors are used in a wide variety of fields. They require different measurement ranges and sensitivities depending on the operating environment because there is generally a trade-off between measurement range and sensitivity. In this study, we developed a variable-sensitivity, variable-measurement-range force sensor that utilizes structural modification, namely changes in the distance between the force application point and the detection area, and changes in the cross-sectional area. The use of shape-memory materials allows the sensor structure to be easily changed and fixed by controlling the temperature. First, we describe the theory of the proposed sensor. Then, we present prototypes and the experimental methods used to verify the performance of the sensor. We fabricated the prototypes by attaching two strain gauges to two sides of a shape-memory alloy and shape-memory polymer plates. Experiments on the prototypes show that the relationship between the applied force and the detected strain can be changed by bending the plate. This allows the sensitivity and measurement range of the sensor to be changed.

DOI： 10.3390/s23042077

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85148968722&origin=inward

Numerical simulation to evaluate guidewire and catheter behavior during catheter introduction 査読有り国際誌

TAKASHIMA Kazuto, NAMBA Akinori, OTA Hiroto, HAGA Yoichi, OHTA Makoto, MORI Koji, TOMA Naoki, SHOJIMA Masaaki

Journal of Biomechanical Science and Engineering ( 一般社団法人日本機械学会 ) 18 ( 1 ) 22-00276 - 22-00276 22-00276 (12pp) 2023年01月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

A national questionnaire survey on guidewire penetration accidents by the Japanese Society for Neuroendovascular Therapy reported examples of perforation accidents occurring “during catheter introduction” (75.2% of accidents). In this study, we evaluated the behavior of a guidewire and a catheter during catheter introduction by numerical simulations, based on the results of the national survey. Using the contact force between the medical devices and the vessel wall, and the medical device position as criteria, we investigated the mechanism and the risk of penetration by the device tip during device introduction. We also evaluated the effects of the insertion velocity of the guidewire and the catheter. The contact force gradually increased during insertion of the guidewire, and the maximum contact force was observed after the guidewire passed through a bend in the blood vessel. After that, when introducing a catheter along the guidewire at the bend in the blood vessel, the guidewire imparted a greater load on the vessel wall than when the guidewire itself was introduced. This is the same tendency seen in our previous study and the national survey. One reason for the force increase during catheter introduction is a decrease in the contact area, which concentrates the contact force. Another reason for the force increase is that the bending stiffness of the guidewire covered by the catheter is the sum of the stiffnesses of the two devices, which is larger than that of only the guidewire. Different from guidewire introduction, as the insertion velocity of the catheter increased, the maximum contact force decreased under the influence of the bend shape and the contact force distribution. Moreover, the guidewire oscillated considerably when the catheter was introduced, and this oscillation increased as the insertion velocity increased, leading to a risk of mistakenly straying into a perforating branch.

DOI： 10.1299/jbse.22-00276

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85174827956&origin=inward

Mechanical modelling and stress-strain prediction of electroactive polymer-based capacitive sensor under multiaxial loads using uniaxial tensile data 査読有り国際誌

Singh N.K., Takashima K., Pandey S.S.

Sensors & Transducers Journal 259 12-18 2022年10月

Fabrication and Evaluation of Catheter-Type Tactile Sensor Composed of Two Polyvinylidene Fluoride Films 査読有り国際誌

K. Takashima, M. Watanabe, K. Inoue, S. Horie, K. Ishida

Proceedings of SICE Annual Conference 2022 1165 - 1170 2022年09月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Japan Kumamoto 2022年09月06日 - 2022年09月09日

To enable quantitative palpation in vivo, we developed a catheter-type tactile sensor composed of two polyvinylidene fluoride (PVDF) films for minimally invasive surgery. In our previous study, we fabricated a prototype catheter-type tactile sensor composed of a PVDF film with an outer diameter of 2 mm. However, this sensor can detect only a uniaxial contact state. In this study, we added a piezoelectric film embedded in silicone rubber to allow the sensor to detect a biaxial contact state. We evaluated the frequency responses of the proposed sensors.

DOI： 10.23919/SICE56594.2022.9905774