Kyushu University Academic Staff Educational and Research Activities Database
List of Papers
Nogami Hirofumi Last modified date:2018.08.05

Assistant Professor / Desigh ・ Bio-system / Department of Mechanical Engineering / Faculty of Engineering

1. Nogami Hirofumi, Shozo Arai, Hironao Okada, Lan Zhan, Toshihiro Itoh, Minimized Bolus-Type Wireless Sensor Node with a Built-In Three-Axis Acceleration Meter for Monitoring a Cow’s Rumen Conditions, Sensors, 10.3390/s17040687, 17, 4, 687, 2017.03.
2. Lan Zhang, Jian Lu, 野上 大史, Hironao Okada, Toshihiro Itoh, ITO-Based MEMS Sensor Electrode for Dynamic Cow-Rumen pH Sensing, IEEJ Transactions on Sensors and Micromachines, 136, 11, 482-487, 2016.11, A solid-type pH sensor for dairy cow-rumen measurement is developed. The pH sensor combines a metal-oxide-semiconductor field-effect transistor (MOSFET) with a separate sensing electrode made of indium tin oxide (ITO) film, which is a separate sensing component and connected to the gate terminal of the FET. The developed pH sensor offers the advantages of FET and ITO sensing techniques. The sensor system can be fabricated with a compact size by eliminating the reference solution. The solid-state sensor structure is fit for long-term pH measurement, and the separate ITO sensing electrode can be patterned with a suitable capture structure for cow-rumen test environment. The results show that the pH sensor has a <1 mA baseline for pH = 7 and >14 µA/pH measurement sensitivity. After good packaging, the solid pH sensor is adapted to sense the daily range of pH value of the rumen, and the developed sensor can help farmers efficiently monitor the health condition of wagyu cows..
3. Lan Zhang, Jian Lu, 野上 大史, Hironao Okada, Toshihiro Itoh, Shozo Arai, Solid-state pH sensor prototype for real-time monitoring of the rumen pH value of Japanese cows, Microsystem Technologies, 1-7, 2017.03, During the growth of Japanese cows, the ruminal pH value is an important physiological parameter, which remarkably affects their nutritional status. To monitor the health condition of the cows and help farmers efficiently manage their livestock, a clear need exists to develop a novel method to efficiently sense the daily range of the rumen pH. Thus, we developed a solid-state pH sensor for real-time monitoring of the rumen pH value of Japanese cows. The indium tin oxide and field-effect transistor-based pH sensor was fabricated and well packaged, and its performance was comprehensively evaluated. The isolation resistance and waterproofing of the packaged sensor were measured, and the functional features fully satisfied the specific requirements. The power consumption of the developed sensor was measured and calculated. The compact pH sensor only incurred a power consumption of 8.2 × 10−4 mA h, which is a low value for a cell battery-powered system. Stability test of the packaged pH sensor was performed, and the developed sensor could well measure an acid solution with a stable output for a relatively long time. The output characteristic of the pH sensor and its field measurement were also presented in this paper..
4. Ryotaro Miura, Koji Yoshioka, Toru Miyamoto, 野上 大史, Hironao Okada, Toshihiro Itoh, Estrous detection by monitoring ventral tail base surface temperature using a wearable wireless sensor in cattle, Animal Reproduction Science, 180, 50-57, 2017.03.
5. 野上 大史, Toshihiro Takeshita, Natsumi Makimoto, 澤田 廉士, Takeshi Kobayashi, Simulation and fabrication of a MEMS optical scanner device considering deformation caused by internal stress, Japanese Journal of Applied Phisics, 55, 10TA11, 2016.09, We fabricated a MEMS actuator device that is used as an actuator component of an optical scanning device without deflection of the device using finite element method (FEM) software. When Pt / Ti / PZT / Pt / Ti / SiO 2 multilayers were deposited on a silicon-on-insulator (SOI) wafer in order to
fabricate the MEMS actuator device, the wafer was deflected because of inner stress generated by thin-film deposition, and as a result, the MEMS actuator device using the deflected wafer was also deflected. We aimed to define the relationship between the deflection of the SOI wafer and the
deflection of the MEMS actuator device by simulation. Moreover, by using this relationship, we determined the optimal deflection of the SOI wafer after the deposition of thin films, enabling the fabrication of a MEMS actuator device without deflection, by simulation. From the simulation result,
when the changes in the deflection of SOI wafers were 14.1 and 7.4 µm, the displacements of the MEMS actuator device were 1.1 and 5.7 µm, respectively. The simulation results were in good agreement with the experimental results. From the simulation results, the optimal wafer deflection
for preventing the deflection of the MEMS actuator device was 15.6 µm. This value was close to the experimental value, 14.1 µm. This method enables easy simulation of any MEMS device that is complicated in design and which uses multilayer thin films..
6. Nobutomo Morita, Nogami Hirofumi, Eiji Higurashi, Takahiro Ito, Renshi Sawada, Development of a Built-In Micro-Laser Doppler Velocimeter, JOURNAL OF MICROELECTROMECHANICA L SYSTEMS, 25, 2, 380-387, 2016.02, Our research group previously developed an integrated micro-laser Doppler velocimeter only 2.8 × 2.8 mm in area and 1-mm thick by minimizing a number of components with multifunctional parts, such as a glass cover with lenses for hermetic sealing and laser collimation, a silicon base for casing, a mirror mount, a laser diode bench, and others. In this paper, by applying a fast Fourier transform analysis to the sensor output, we successfully measured the velocities of plastic, paper, and aluminum objects over a wide velocity range, from 10 μm/s to 10 mm/s, within a 3.3% measurement error, without attaching any scale to the measurement target. We also verified feasible measurement distances for each object and examined how tilt installation error affected the measurements..
7. Toshihiro Takeshita, Kota Harisaki, Hideyuki Ando, Eiji Higurashi, Hirofumi Nogami, Renshi Sawada, Development and evaluation of a two-axial shearing force sensor consisting of an optical sensor chip and elastic gum frame, Precison Engineering, 45, 136-143, 2016.02, We developed a promising shearing force sensor that is small in size and can measure shearing force along two axes independently. This sensor consists of an elastic gum frame and an optical sensor chip (6 mm × 6 mm × 8 mm). From the experimental results, the resolutions of the sensor along the x- and y-axes are found to be 0.070 N and 0.063 N. We also experimentally demonstrated that the sensor can separately measure shearing force along two axes. Finally, we demonstrated that the scale factor which correspond to resolution and linear portion which correspond to measuring range of the signals can be changed easily by using three types of elastic gum frame. This sensor can be embedded in the finger of a robot hand and use it to not only measure shearing force but also detect the slip phenomenon..
8. Wataru Iwasaki, Hirofumi Nogami, Satoshi Takeuchi, Masutaka Furue, Eiji Higurashi, Renshi Sawada, Detection of Site-Specific Blood Flow Variation in Humans during Running by a Wearable Laser Doppler Flowmeter, Sensors, 15, 10, 25507-25519, 2015.10, Wearable wireless physiological sensors are helpful for monitoring and maintaining human health. Blood flow contains abundant physiological information but it is hard to measure blood flow during exercise using conventional blood flowmeters because of their size, weight, and use of optic fibers. To resolve these disadvantages, we previously developed a micro integrated laser Doppler blood flowmeter using microelectromechanical systems technology. This micro blood flowmeter is wearable and capable of stable measurement signals even during movement. Therefore, we attempted to measure skin blood flow at the forehead, fingertip, and earlobe of seven young men while running as a pilot experiment to extend the utility of the micro blood flowmeter. We measured blood flow in each subject at velocities of 6, 8, and 10 km/h. We succeeded in obtaining stable measurements of blood flow, with few motion artifacts, using the micro blood flowmeter, and the pulse wave signal and motion artifacts were clearly separated by conducting frequency analysis. Furthermore, the results showed that the extent of the changes in blood flow depended on the intensity of exercise as well as previous work with an ergometer. Thus, we demonstrated the capability of this wearable blood flow sensor for measurement during exercise..
9. Bin Sun, Hirfoumi Nogami, Yao Pen and Renshi Sawada, Microelectromagnetic actuator based on a 3D printing process for fiber scanner application, Journal of Micromechanics and Microengineering, 25, 7, 2015.06, A novel electromagnetic-actuated fiber scanner has been proposed for ultra-thin scanning fiber
endoscope application. A free-fixed optical fiber cantilever with a cylindrical magnet can be
driven and vibrated by a tilted coil on a tube surface under electromagnetic force. The tiny coil
with a large tilt angle as the actuator is fabricated by a new three-dimensional (3D) printing
technology and handmade hybrid process. It is an efficient and low-cost method for fabricating
tiny 3D tilted coils compared with the complicated micromachining process. A 2.0 mm outer
diameter tilted coil has been successfully developed. The line pitch, tilt angle, resistance and
turns of this fabricated coil are 75 µm, 60°, 20 Ω and 100 turns, respectively. The scanning
motion of the assembled scanner utilizing the fabricated 3D coil, fiber and a small magnet has
been measured by a high-speed camera. The scanner consists of a 9 mm-length optical fiber, a
2 mm outer diameter cylindrical magnet, a jig and a fabricated tilted coil.
The displacement of the fiber tip in the scanner is observed and measured when the
alternative current-driven voltage was applied to the tilted coil, and 126.8 µm maximum
displacement has been obtained. The present fiber scanner with 3D tilted coil has promise for
use as an important inspecting device for biomedical endoscope application..