IEEJ Transactions on Sensors and Micromachines
Online ISSN : 1347-5525
Print ISSN : 1341-8939
ISSN-L : 1341-8939
Current issue
Showing 1-10 articles out of 10 articles from the selected issue
Paper
  • Akira Yoshida, Yu Oguro, Masayuki Sohgawa, Takashi Abe
    2020 Volume 140 Issue 10 Pages 251-255
    Published: October 01, 2020
    Released: October 01, 2020
    JOURNALS RESTRICTED ACCESS

    In this paper, we developed a quartz oscillator based liquid concentration sensor for contactless monitoring of water treatment process. This sensor is composed of the sensing capacitor (SC) and quartz crystal resonator (QCR). The proposed sensor is a contactless capacitive sensor using out-of-plane electric field of a planer sensing capacitor. We succeeded in measuring flocculation reaction of coagulant and sewage. This study is expected to reduce the time significantly to determine the amount of coagulant and to develop automatic control of the water treatment process.

    Download PDF (1092K)
  • Nao Igawa, Tomoyuki Yokogawa, Kento Fujii, Isao Kayano, Yoichiro Sato, ...
    2020 Volume 140 Issue 10 Pages 256-264
    Published: October 01, 2020
    Released: October 01, 2020
    JOURNALS RESTRICTED ACCESS

    In this paper, we propose a contact-less heartbeat monitoring system for in-vehicle R-R Interval (RRI) measurement using a UWB sensor. Our system extracts a heartbeat by noise filtering with a bandpass Butterworth filter to remove a noise caused by inside/outside of the driving vehicle. We carried out an experiment to evaluate the accuracy of RRI detection of our system by comparing it with MIMO radar, which is used widely for moving object detection. We evaluated the accuracy of RRI detection of our system by using Bland-Altman plot with the RRI obtained by myBeat, which is an existing contact-type heartbeat monitoring device. Consequently, the RRI measured by our system is more accurate than that measured by MIMO radar and is comparable to the RRI measured by myBeat.

    Download PDF (2621K)
  • Yoichi Haga, Kei Okuda, Noriko Tsuruoka, Taichi Suzuki, Katsuhiro Fuji ...
    2020 Volume 140 Issue 10 Pages 265-271
    Published: October 01, 2020
    Released: October 01, 2020
    JOURNALS RESTRICTED ACCESS

    Several stress load influences our body as stress reaction. In the case of artery, contraction of smooth muscle of arterial wall is dynamically influenced by stress load as changes in vascular tone. Stress measurement system using diameter changes in artery of forearm has been developed. Changes of blood vessel diameter in radial artery was measured using ultrasound. Firstly, changes in radial arterial diameter of human were measured during stress load by a commercial ultrasonic equipment. Two kinds of stress were loaded, one is physical stress load (cold water load) and the other is mental stress load (mental arithmetic load). Arterial stiffness which reflects vascular tone was calculated using measured blood pressure and measured arterial diameter as inflation difficulty of blood vessel wall. Arterial stiffness was dynamically changed according to stress load. In the case of using commercial ultrasonic equipment, blood vessel diameter was derived from ultrasonic B-mode image of blood vessel and the ultrasonic probe and the system are relatively big, complicated and expensive. Simple and small size ultrasonic blood vessel diameter measurement sensor and system have been developed using MEMS process. To evaluate accuracy of the developed sensor and the system, comparison between measured data from fabricated sensor system and measured data from the commercial ultrasonic equipment was performed using blood vessel model. Acquired diameters were well correlated according to diameter change of the vessel model by changing internal pressure of the vessel model during step change and pulsatile change of internal pressure of the vessel model.

    Download PDF (2885K)
  • Yuto Abe, Fumitoshi Suga, Takashi Abe, Haruo Noma, Masayuki Sohgawa
    2020 Volume 140 Issue 10 Pages 272-277
    Published: October 01, 2020
    Released: October 01, 2020
    JOURNALS RESTRICTED ACCESS

    We fabricated a MEMS tactile sensor which can detect a wide area by sealing a cantilever with a 4.2 mm thick and 50 mm square elastomer. To evaluate the detection range of this sensor, dependence of response to application of normal force on the distance from the cantilever was evaluated. As a result, it is shown that the cantilever can detect force application up to around 5 mm away from it. In addition, it is shown that the sensitivity to force applied just above the cantilever becomes small because the lateral and vertical deformations of the elastomer cancel each other. On the other hand, it is found that the sensitivity monotonically decreases with distance from the cantilever in the cross direction. Therefore, it is considered that this sensor can estimate the position of force application in 2-dimensional surface by using several differently oriented cantilevers.

    Download PDF (1117K)
  • Yukio Suzuki, Eiki Ohyanagi, Hirofumi Chiba, Kosuke Hikichi, Toshiya K ...
    2020 Volume 140 Issue 10 Pages 278-284
    Published: October 01, 2020
    Released: October 01, 2020
    JOURNALS RESTRICTED ACCESS

    Static pure torsion fracture tester for silicon torsional bar was developed. Screening of process factor for silicon torsional bar by static pure torsion destructive test was demonstrated. Planarization of Deep RIE process surface by chemical dry etch (CDE) shows improvement for torsion fracture angle. Reducing surface crystal defect in Deep RIE process surface by hydrogen anneal shows significant improvement in torsion fracture angle.

    Download PDF (2840K)
  • Takashi Miyazaki, Yoshikazu Hirai, Ken-ichiro Kamei, Toshiyuki Tsuchiy ...
    2020 Volume 140 Issue 10 Pages 285-292
    Published: October 01, 2020
    Released: October 01, 2020
    JOURNALS RESTRICTED ACCESS

    Trans-epithelial electrical resistance (TEER) is a widely used non-invasive and label-free measurement to evaluate the barrier function of mono-layered cells in real-time. However, TEER values depend on distribution of electric current densities generated by a combination of shapes and arrangements of plane electrodes for performing TEER, but until now, there is no systematical analysis of their effects on TEER values, causing less reproducibility. Here, we report a new strategy to design the shapes and arrangements of electrodes to perform TEER in a microfluidic device. To investigate the effects of the electrodes design on TEER values, we analyze the distribution of electric current densities using finite element method and evaluate their uniformity of sensitivity. Our strategy allowed designing several electrode patterns of electrodes combinations, capable of simultaneous cell observation with a microscope and TEER measurements.

    Download PDF (1605K)
 
feedback
Top