論文 - 高橋　英俊

Micro Water Flow Measurement Using a Temperature-Compensated MEMS Piezoresistive Cantilever

Pommois Romain, Furusawa Gaku, Kosuge Takuya, Yasunaga Shun, Hanawa Haruki, Takahashi Hidetoshi, Kan Tetsuo, Aoyama Hisayuki

MICROMACHINES （Micromachines）  11 （ 7 ）  2020年07月

　概要を見る

In this study, we propose a microelectromechanical system (MEMS) force sensor for microflow measurements. The sensor is equipped with a flow sensing piezoresistive cantilever and a dummy piezoresistive cantilever, which acts as a temperature reference. Since the dummy cantilever is also in the form of a thin cantilever, the temperature environment of the dummy sensor is almost identical to that of the sensing cantilever. The temperature compensation effect was measured, and the piezoresistive cantilever was combined with a gasket jig to enable the direct implementation of the piezoresistive cantilever in a flow tube. The sensor device stably measured flow rates from 20 μL/s to 400 μL/s in a silicon tube with a 2-mm inner diameter without being disturbed by temperature fluctuations.

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Reconfigurable Surface Plasmon Resonance Photodetector with a MEMS Deformable Cantilever

M Oshita, H Takahashi, Y Ajiki, T Kan

ACS Photonics （ACS Photonics）  7 （ 3 ） 673 - 679 2020年

ISSN  2330-4022

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Plasmonic photodetectors have many useful characteristics, such as wavelength- or polarization-specific photodetection. Although reconfigurable plasmonic structures have been intensively studied, reconfiguration of the optical characteristics of a plasmonic photodetector has not yet been reported. Here, we report a gold diffraction-grating-type plasmonic photodetector that reconfigures its optical characteristics with a MEMS deformable cantilever. By reconfiguring the photodetector characteristics using an angular scan of the cantilever over -21° to 21°, the peak shifts of the photocurrent signal waveform are found to depend on the wavelength over 1200∼1500 nm, which is consistent with SPR theory. The proposed reconfigurable plasmonic photodetector allowed us to obtain spectroscopic information on the light in a demonstration experiment.

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PIPETTE BASED VISCOMETER WITH PRESSURE SENSOR ELEMENT

Cho Sinwoo, Thanh-Vinh Nguyen, Miki Norihisa, Takahashi Hidetoshi

2020 33RD IEEE INTERNATIONAL CONFERENCE ON MICRO ELECTRO MECHANICAL SYSTEMS (MEMS 2020) （Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS)）  2020-January   646 - 648 2020年

ISSN  1084-6999

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This paper reports a simple viscometer, whose principle utilizes the relationship between liquid viscosity and the suction speed in a tube. The proposed viscometer is composed of an air chamber and a glass tube. A steel ball is attached to the silicone membrane of the chamber and an electromagnetic magnet is used to provide the volume change. A MEMS pressure sensor element is attached to the chamber to measure its pressure change. When a step-response volume change is applied, the chamber pressure decreases so that the liquid sticking to the tube gradually ascends at a speed depending to the viscosity. Thus, the viscosity can be calculated by measuring the gradient of the pressure change. The proposed method can be applied to micropipettes so that viscosity is easily measured with a simple device.

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DIRECT FABRICATION OF PEGDA MICRO SUCTION CUP ARRAY USING INCLINED/ROTATING MIRROR EXPOSURE SYSTEM

Sugimoto Takumi, Takahashi Hidetoshi

2020 33RD IEEE INTERNATIONAL CONFERENCE ON MICRO ELECTRO MECHANICAL SYSTEMS (MEMS 2020) （Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS)）  2020-January   925 - 927 2020年

ISSN  1084-6999

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This paper reports on direct fabrication method of a PEGDA micro suction cup array. A micro suction cup has been attracted in many application, however, conventional fabrication method using mold has limitation of the shape of the fabricated structure. The proposed fabrication method realizes a micro suction cup array with single exposure dose by inclined/rotating exposure system. As the suction cup material, UV curable Poly (ethylene glycol) diacrylate (PEGDA) is used due to its suitable characteristics. By controlling the inclined angle and mask pattern, the shape of micro suction cup can be designed. We conducted fabrication experiment of suction cup array of 200 mumathrm{m} in diameter to confirm our proposed method is useful.

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Densely Arrayed Active Antennas Embedded in Vertical Nanoholes for Backside‐Illuminated Silicon‐Based Broadband Infrared Photodetection

S Yasunaga, H Takahashi, T Takahata, I Shimoyama, T Kan

Advanced Materials Interfaces 7 (21), 2001039 2020年

3D HYDROGEL MANUFACTURING EMPLOYING SELF-FOCUSING DURING PHOTO-CURING PROCESS

Lee Gayeong, Takahashi Hidetoshi, Kan Tetsuo, Kim Jieun, Donmez Nilsu, Park Jihoon, Kim Dongwook, Ka Sanghoon, Nam Misong, Lim Donggi, Heo Yun Jung

2020 33RD IEEE INTERNATIONAL CONFERENCE ON MICRO ELECTRO MECHANICAL SYSTEMS (MEMS 2020) （Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS)）  2020-January   323 - 324 2020年

ISSN  1084-6999

　概要を見る

This work proposes a 3D lithography technique with self-focusing during polymerization based on refractive-indices change of polyethylene glycol diacrylate (PEGDA) (Fig. 1). Compared to the previous work, the present work enables to fabricate 3D structures using single UV exposure and theoretically estimate 3D features. We demonstrate the potential of the self-focusing 3D lithography by fabricating PEGDA microneedles and trapezoid-shaped wells. Their structures well match to our theoretical estimation. Therefore, our theoretical approach shows its potential for on-demand, complicated 3D structures of refractive-indices-variable materials with single UV exposure.

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Assessment of the risk of malnutrition due to aspiration pneumonia and oral feeding difficulty

S Sato, H Takahashi

Nutrición hospitalaria: Órgano oficial de la Sociedad Española de Nutrición … 2020年

A MEMS-based measurement system for evaluating the force-length relationship of human induced pluripotent stem cell-derived cardiomyocytes adhered on a substrate

K Matsudaira, H Takahashi, KH Shoji, TV Nguyen, T Tsukagoshi, ...

Journal of Micromechanics and Microengineering （Journal of Micromechanics and Microengineering）  29 （ 5 ）  2019年

ISSN  09601317

　概要を見る

This paper reports on a method for evaluating the force-length relationship of adhering human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) on the substrate using a measurement system comprising of a micromachined movable plate and a piezoresistive force probe. The cells on the plate are stretched by pushing the movable plate with the piezoresistive cantilever, which is actuated by a piezo stage. The twitch forces and the applied stretch are measured quantitatively with the piezoresistive cantilever. The results demonstrated that the twitch forces of the hiPSC-CMs increased when a stretch was applied. This evaluation method improves the understanding of the intrinsic force-length relationship of hiPSC-CMs at the cellular scale.

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Sensor

I Shimoyama, K Matsumoto, BK Nguyen, H Takahashi, MD Nguyen, ...

US Patent App. 10/234,429 2019年

Highly sensitive and low-crosstalk angular acceleration sensor using mirror-symmetric liquid ring channels and MEMS piezoresistive cantilevers

H Takahashi, T Kan, A Nakai, T Takahata, T Usami, I Shimoyama

Sensors and Actuators A: Physical 287, 39-47 （Sensors and Actuators, A: Physical）  287   39 - 47 2019年

ISSN  09244247

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© 2019 This paper describes an angular acceleration sensor that uses liquid ring channels and piezoresistive cantilevers. The detection of fluidic rotation has attracted attention as a sensing principle for angular acceleration due to the simple structure and potentially low power consumption of devices that use said principle. Although the existing angular acceleration sensors that use this sensing principle have the potential for high sensitivity to angular acceleration about the target axis, crosstalk is an issue—specifically, crosstalk with angular accelerations about other axes and with linear acceleration. Here, we propose an angular acceleration sensor that uses a MEMS piezoresistive cantilever as the sensing element and two mirror-symmetric ring channels. This mirror symmetry cancels out the signals due to accelerations about the other axes, while the signal for the angular acceleration about the target axis is doubled. The experimental results show that the sensitivity to other axial angular accelerations and linear acceleration is sufficiently small. The obtained sensitivity for the angular acceleration is as high as 3.1 × 10 −4 (rad/s 2 ) -1 , similar to theoretical predictions. This value for the sensitivity is maintained over a range of frequencies from 0.1 Hz to 100 Hz. Therefore, the proposed sensor is suitable for practical angular acceleration detection applications.

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Monitoring Volcanic Activity with High Sensitive Infrasound Sensor Using a Piezoresistive Cantilever

J Shimatani, H Takahashi, M Ichihara, T Takahata, I Shimoyama

2019 IEEE 32nd International Conference on Micro Electro Mechanical Systems … （Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS)）  2019-January   783 - 786 2019年

ISSN  9781728116105

　概要を見る

© 2019 IEEE. In this paper, we propose a high sensitive monitoring method of infrasound evoked by a volcano eruption. The sensor unit is composed of two differential pressure sensors and an air chamber. The pressure resolution of the developed sensor is approximately 0.01 Pa, which is sufficiently small to detect the tiny infrasound. The measurable frequency range is from 0.3 Hz, which is sufficiently low for the infrasound. The sensor units were set at the foot of volcano, Sakurajima, Kagoshima, Japan. It was confirmed that the sensors kept the high sensitive monitoring performance for a month.

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Underwater Pitot Tube for Swimming Animals

T Hagiwara, H Takahashi, TV Nguyen, T Takahata, I Shimoyama

2019 IEEE 32nd International Conference on Micro Electro Mechanical Systems … （Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS)）  2019-January   95 - 98 2019年

ISSN  9781728116105

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© 2019 IEEE. This paper reports on an underwater Pitot tube which is designed for swimming measurement of marine animals. The tubes of the Pitot tube are filled with incompressive liquid and sealed by thin films so that the device can be used even when plunged into water. The Pitot tube has a pressure sensor inside that consists of a piezoresistive cantilever incorporated into a thin Parylene-C membrane. When a water flow is applied to the Pitot tube, the thin films at the inlets act as elastic membranes and the liquid filled in the tubes transmits the pressure to the pressure sensor. The proposed Pitot tube can be used as a water flow speedometer for biological studies of marine animals.

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Infrared Photodetector with Copper Resonator in Silicon Nanohole Array

S Yasunaga, T Kan, H Takahashi, T Takahata, I Shimoyama

2019 20th International Conference on Solid-State Sensors, Actuators and … （2019 20th International Conference on Solid-State Sensors, Actuators and Microsystems and Eurosensors XXXIII, TRANSDUCERS 2019 and EUROSENSORS XXXIII）     633 - 636 2019年

ISSN  9781728120072

　概要を見る

© 2019 IEEE. A silicon-based infrared photodetector with metal nanostructures has been drawing attention, while lacking sufficient responsivity. We hereby present a silicon-based infrared photodetector furnished with an array of a nano-scale copper plate which induces localized surface plasmon resonance (LSPR). Each plate is placed at the bottom of a nanohole on a silicon substrate. This device possesses two features: electrically-connected copper resonators and backside-illuminating configuration. They lead to efficient photocurrent generation. As LSPR couples with vertically incident light, this structure can be a solution of realizing a silicon-based infrared photodetector that can be adapted to prevalent semiconductor devices.

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An MRI-Compatible Force Sensor with Enclosed Air Using Pressure Transmission

D Akutagawa, T Izumizaki, M Hori, H Takahashi, I Shimoyama, T Dohi

2019 IEEE 32nd International Conference on Micro Electro Mechanical Systems … （Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS)）  2019-January   803 - 806 2019年

ISSN  9781728116105

　概要を見る

© 2019 IEEE. We fabricated an MRI-compatible force sensor with enclosed air using pressure transmission. The fabricated force sensor consists of a contact portion, sensing portions, and connecting pipes. When force was applied to the contact portion, the internal air pressure increased with a deformation of the contact portion, and is transmitted to the sensing portion through the connecting pipes. In the sensing portion, the change in air pressure is detected by a change in the resistance of a piezoresistive cantilever. Since using this air pressure transmission, the sensing portion can be placed away from the magnet of the MRI. Therefore, the force sensor does not interfere with the magnetic field, and it can be used in the magnet of an MRI.

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Highly Sensitive Angular Accelerometer Utilizing Piezoresistive Cantilever and Spiral Liquid Channel

B Jo, H Takahashi, T Takahata, I Shimoyama

2019 IEEE 32nd International Conference on Micro Electro Mechanical Systems … （Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS)）  2019-January   206 - 209 2019年

ISSN  9781728116105

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© 2019 IEEE. This paper reports a highly sensitive angular accelerometer utilizing a piezoresistive cantilever and spiral liquid channels. The spiral structure increases the total inertial force of liquid due to angular acceleration, which leads to the sensitivity enhancement. The differential pressure between two spiral liquid channels was measured by a piezoresistive cantilever with the resolution of 0.01 Pa. The developed sensor with number of turns of the spiral with 25 achieved the sensitivity enhancement by 28.5 times, compared to the ring channel sensor.

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In-Plane Gyroscope Using a Piezoresistive Beams with Sidewall Doping

K Abe, H Takahashi, T Takahata, I Shimoyama

2019 IEEE 32nd International Conference on Micro Electro Mechanical Systems … （Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS)）  2019-January   680 - 683 2019年

ISSN  9781728116105

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© 2019 IEEE. This paper reports a gyroscope using sidewall doped piezoresistors and vibrating mass by Lorentz force. With sidewall doped piezoresistors, in-plane deformation of the beams due to Coriolis force generated by angular motion can be detected, which was difficult with surface doped piezoresistors. The proposed gyroscope was designed so that the resonant frequencies of the driving and sensing modes were similar to each other. It was demonstrated that the developed gyroscope measured angular velocity through the resistance change of the piezoresistive beams.

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Waterproof airflow sensor for seabird bio-logging using a highly sensitive differential pressure sensor and nano-hole array

Hidetoshi Takahashi, Akihito Nakai and Isao Shimoyama

Sensors & Actuators A: Physical （Sensors and Actuators, A: Physical）  281   243 - 249 2018年10月

研究論文（学術雑誌）, 共著, 査読有り,  ISSN  09244247

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© 2018 Elsevier B.V. This paper presents an airflow sensor for seabird bio-logging. Although bio-logging methods have attracted attention in the evaluation of seabird flight performance, the airflow velocity has not been directly measured. Here, an airflow sensor is added to the bio-logging system, and a direct airflow velocity measurement is applied, thus enabling more accurate evaluation of the flight performance. To attach the sensor to the bio-logging system, the sensor must be waterproof because seabirds dive into the sea to prey on fish. In addition, the sensor must also be compact and have high sensitivity. Here, we propose a Pitot tube-type airflow sensor that satisfies these requirements. The proposed sensor is composed of microelectromechanical systems (MEMS) piezoresistive cantilevers as sensing elements with high sensitivity and anodic alumina membranes with a nano-hole array as the waterproof elements with airflow penetration. The developed sensor responded sufficiently to airflow velocities from 2 m/s to 20 m/s. In addition, the sensor maintained its sensitivity after plunging into the water and returning to the air. Therefore, the proposed sensor can be utilized for practical seabird bio-logging.

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Experimental study of the aerodynamic interaction between the forewing and hindwing of a beetle-type ornithopter

Hidetoshi Takahashi, Kosuke Abe, Tomoyuki Takahata, Isao Shimoyama

Aerospace （Aerospace）  5 （ 3 ） 83 2018年08月

研究論文（学術雑誌）, 共著, 査読有り

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© 2018 by the authors. Beetles have attracted attention from researchers due to their unique combination of a passively flapping forewing and an actively flapping hindwing during flight. Because the wing loads of beetles are larger than the wing loads of other insects, the mechanism of beetle flight is potentially useful for modeling a small aircraft with a large weight. In this paper, we present a beetle-type ornithopter in which the wings are geometrically and kinematically modeled after an actual beetle. Furthermore, the forewing is designed to be changeable between no-wing, flapping-wing, or fixed-wing configurations. Micro-electro-mechanical systems (MEMS) differential pressure sensors were attached to both the forewing and the hindwing to evaluate the aerodynamic performance during flight. Whether the forewing is configured as a flapping wing or a fixed wing, it generated constant positive differential pressure during forward flight, whereas the differential pressure on the hindwing varied with the flapping motion during forward flight. The experimental results suggest that beetles utilize the forewing for effective vertical force enhancement.

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薄膜メタマテリアル実現に向けたフレーム構造のTHz応答解析

磯崎瑛宏, 菅哲朗, 高橋英俊, 松本潔, 下山勲

電気学会論文誌E 138 （ 7 ） 281 - 286 2018年07月

研究論文（学術雑誌）, 共著, 査読有り

Development of a light source with a uniform intensity reinforced by a checkerboard half-mirror positioned within inverse L-shaped UV-LED arrays

Hidetoshi Takahashi, Isao Shimoyama and Yun Jung Heo

Applied Physics Express （Applied Physics Express）  11 （ 6 ） 066701 2018年05月

研究論文（学術雑誌）, 共著, 査読有り,  ISSN  18820778

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© 2018 The Japan Society of Applied Physics. This paper presents a simple, low-cost, long-lasting UV-LED-based light source with uniform light intensity using a checkerboard half-mirror positioned within inverse L-shaped UV-LED arrays. The light rays from the top UV-LED array passed through the transparent portions of the checkerboard half-mirror, while the light rays from the side UV-LED array were reflected on the remaining opaque portions at right angles. Thus, uniform light intensity was achieved on the bottom area. Using the developed UV-LED light source, we fabricated microstructures with uniform shapes on a large area, thereby showing feasible applications for MEMS fabrication.

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