The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform

A Vera - One of the best experts on this subject based on the ideXlab platform.

  • a model for radial modes in Piezoelectric Disk exhibiting bessel polarizations
    Applied Physics Letters, 2007
    Co-Authors: H Calas, J Figueredo, E Moreno, J A Eiras, L Leija, A Vera
    Abstract:

    In this contribution, a model for radial modes in nonhomogeneus poled Piezoelectric Disk is being presented. Such a model is achieved by assuming a direct correspondence between the Piezoelectric coefficients and the poling profile. This model was applied to a Piezoelectric Disk poled following a zeroth-order first-kind Bessel function, which depends on a scaling parameter, with the purpose of clarify the modal behavior in Bessel transducers. The influence of such parameter on the electrical response of the Disk was studied numerically. The theoretical results were verified by the comparison with experimental results obtained for three modal Bessel transducers.

Masanori Yachi - One of the best experts on this subject based on the ideXlab platform.

  • Electrode Design of Single Crystal Lithium Niobate Piezoelectric Disk Gyroscope
    2020 IEEE International Symposium on Inertial Sensors and Systems (INERTIAL), 2020
    Co-Authors: Kazutaka Obitani, Jin Qian, Toshiyuki Tsuchiya, Kazutaka Araya, Masanori Yachi
    Abstract:

    This paper reports optimization of electrode arrangement of Piezoelectric Disk gyroscope using single crystal lithium niobate (LN). The Disk was fabricated from a 155°-Y cut LN wafer in which the elastic compliance is uniform in any in-plane directions to realize mode-matching in two wineglass modes for gyroscope operation. To mitigate anisotropic Piezoelectric properties of the LN wafer, the electrode patterns on both sides of Disk were optimized. For 45°-mode operation, eight segmented electrodes were designed by considering the opposite polarity of the transverse Piezoelectric constants d31 and d32, whereas the 0°-mode was oscillated with single electrode. Angular rate was successfully detected using LN Disk resonator of the 25.8-mm-diameter and 330-μm thickness.

  • Single-Crystal Lithium Niobate Piezoelectric Disk Gyroscope
    2020 IEEE 33rd International Conference on Micro Electro Mechanical Systems (MEMS), 2020
    Co-Authors: Kazutaka Obitani, Toshiyuki Tsuchiya, Kazutaka Araya, Masanori Yachi
    Abstract:

    A mode-matched single-crystal lithium niobate (SC-LN) Disk gyroscope has been developed, for the first time, to realize a tactical grade MEMS gyroscope. SC-LN is suitable for Piezoelectric transducers because of its high Q-factor and electromechanical coupling coefficient. However, its crystallographic anisotropy prevents from making Disk-shaped mode-matched gyroscope. We discovered an optimum orientation to realize uniform in-plane elastic compliance. We designed sixteen-electrode for driving and detecting two modes for operation. Brittle SC-LN Disk resonators were processed using a core drill machine. The as-fabricated Disk showed 95 kHz wineglass modes with less than 200 Hz frequency split. The angular rate output was successfully obtained and we demonstrated the potential for realizing high performance SC-LN gyroscope.

Takeshi Matsumura - One of the best experts on this subject based on the ideXlab platform.

  • vibration mode observation of Piezoelectric Disk type resonator by high frequency laser doppler vibrometer
    Electronics and Communications in Japan, 2012
    Co-Authors: Masayoshi Esashi, Hiroshi Harada, Takeshi Matsumura, Shuji Tanaka
    Abstract:

    For future mobile phones based on cognitive radio technology, a compact multiband RF front-end architecture is strongly required, and an integrated multiband RF filter bank is a key component in it. Contour-mode resonators are receiving increased attention for a multiband filter solution, because their resonance frequency is mainly determined by their size and shape, which are defined by lithography. However, spurious responses, including flexural vibration, are also excited due to the thin structure of the devices. To improve resonator performance and suppress spurious modes, visual observation with a laser probe system is very effective. In this paper, we prototyped a mechanically coupled Disk-array filter, which consists of a silicon Disk and two Disk-type resonators of higher-order wineglass mode, and observed its vibration modes using a high-frequency laser Doppler vibrometer (UHF-120, Polytec, Inc.). It was confirmed that the higher-order wineglass mode vibration included a compound displacement, and that its out-of-plane vibration amplitude was much smaller than that of other flexural spurious modes. The observed vibration modes were compared with FEM (Finite Element Method) simulation results. In addition, it was also confirmed that fabrication error (e.g., misalignment) induced asymmetric vibration. © 2012 Wiley Periodicals, Inc. Electron Comm Jpn, 95(5): 33–41, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.10406

  • Vibration mode observation of Piezoelectric Disk-type resonator by high-frequency laser Doppler vibrometer
    Electronics and Communications in Japan, 2012
    Co-Authors: Takeshi Matsumura, Masayoshi Esashi, Hiroshi Harada, Shuji Tanaka
    Abstract:

    For future mobile phones based on cognitive radio technology, a compact multiband RF front-end architecture is strongly required, and an integrated multiband RF filter bank is a key component in it. Contour-mode resonators are receiving increased attention for a multiband filter solution, because their resonance frequency is mainly determined by their size and shape, which are defined by lithography. However, spurious responses, including flexural vibration, are also excited due to the thin structure of the devices. To improve resonator performance and suppress spurious modes, visual observation with a laser probe system is very effective. In this paper, we prototyped a mechanically coupled Disk-array filter, which consists of a silicon Disk and two Disk-type resonators of higher-order wineglass mode, and observed its vibration modes using a high-frequency laser Doppler vibrometer (UHF-120, Polytec, Inc.). It was confirmed that the higher-order wineglass mode vibration included a compound displacement, and that its out-of-plane vibration amplitude was much smaller than that of other flexural spurious modes. The observed vibration modes were compared with FEM (Finite Element Method) simulation results. In addition, it was also confirmed that fabrication error (e.g., misalignment) induced asymmetric vibration. © 2012 Wiley Periodicals, Inc. Electron Comm Jpn, 95(5): 33-41, 2012; Published online in Wiley Online Library (). DOI 10.1002/ecj.10406 [ABSTRACT FROM AUTHOR]

  • vibration mode observation of Piezoelectric Disk type resonator by high frequency laser doppler vibrometer
    Ieej Transactions on Electronics Information and Systems, 2011
    Co-Authors: Masayoshi Esashi, Hiroshi Harada, Takeshi Matsumura, Shuji Tanaka
    Abstract:

    For future mobile phones based on cognitive radio technology, a compact multi-band RF front-end architecture is strongly required and an integrated multi-band RF filter bank is a key component in it. Contour-mode resonators are receiving increased attention for a multi-band filter solution, because its resonant frequency is mainly determined by its size and shape, which are defined by lithography. However, spurious responses including flexural vibration are also excited due to its thin structure. To improve resonator performance and suppress spurious modes, visual observation with a laser probe system is very effective. In this paper, we have prototyped a mechanically-coupled Disk-array filter, which consists of a Si Disk and 2 Disk-type resonators of higher-order wine-glass mode, and observed its vibration modes using a high-frequency laser-Doppler vibrometer (UHF-120, Polytec, Inc.). As a result, it was confirmed that higher order wine-glass mode vibration included a compound displacement, and that its out-of-plane vibration amplitude was much smaller than other flexural spurious modes. The observed vibration modes were compared with FEM (Finite Element Method) simulation results. In addition, it was also confirmed that the fabrication error, e.g. miss-alignment, induced asymmetric vibration.

  • Selective mode excitation of Piezoelectric Disk-type resonator by electrode pattern definition
    2010 IEEE International Ultrasonics Symposium, 2010
    Co-Authors: Takeshi Matsumura, Masayoshi Esashi, Hiroshi Harada, Florian Thalmayr, Ken-ya Hashimoto, Shuji Tanaka
    Abstract:

    Contour-mode Piezoelectric MEMS resonators have been widely studied as one of potential components for future multi-band RF solution based on cognitive radio technology, because its resonant frequency is generally determined by the size and shape. To apply them to applications at frequency of higher than hundreds MHz, a specific higher mode should be strongly excited. However, it is often difficult, because the higher order vibration is a compound mode including radial and rotational displacements. In this study, the displacement distributions of higher order wine-glass modes of Disk-type resonators were derived from FEM modal analysis. Then, mechanically-coupled Disk-array filters with baseball-type and doughnut-type electrodes were fabricated and tested. Using the doughnut-type electrodes, (2. 6) mode was selectively excited, and a filter characteristic at a center frequency of 500.3 MHz was obtained. It was numerically and experimentally confirmed that a well-designed electrode pattern enhanced a specific vibration mode and suppressed other modes by comparing different electrode patterns.

Shuji Tanaka - One of the best experts on this subject based on the ideXlab platform.

  • vibration mode observation of Piezoelectric Disk type resonator by high frequency laser doppler vibrometer
    Electronics and Communications in Japan, 2012
    Co-Authors: Masayoshi Esashi, Hiroshi Harada, Takeshi Matsumura, Shuji Tanaka
    Abstract:

    For future mobile phones based on cognitive radio technology, a compact multiband RF front-end architecture is strongly required, and an integrated multiband RF filter bank is a key component in it. Contour-mode resonators are receiving increased attention for a multiband filter solution, because their resonance frequency is mainly determined by their size and shape, which are defined by lithography. However, spurious responses, including flexural vibration, are also excited due to the thin structure of the devices. To improve resonator performance and suppress spurious modes, visual observation with a laser probe system is very effective. In this paper, we prototyped a mechanically coupled Disk-array filter, which consists of a silicon Disk and two Disk-type resonators of higher-order wineglass mode, and observed its vibration modes using a high-frequency laser Doppler vibrometer (UHF-120, Polytec, Inc.). It was confirmed that the higher-order wineglass mode vibration included a compound displacement, and that its out-of-plane vibration amplitude was much smaller than that of other flexural spurious modes. The observed vibration modes were compared with FEM (Finite Element Method) simulation results. In addition, it was also confirmed that fabrication error (e.g., misalignment) induced asymmetric vibration. © 2012 Wiley Periodicals, Inc. Electron Comm Jpn, 95(5): 33–41, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.10406

  • Vibration mode observation of Piezoelectric Disk-type resonator by high-frequency laser Doppler vibrometer
    Electronics and Communications in Japan, 2012
    Co-Authors: Takeshi Matsumura, Masayoshi Esashi, Hiroshi Harada, Shuji Tanaka
    Abstract:

    For future mobile phones based on cognitive radio technology, a compact multiband RF front-end architecture is strongly required, and an integrated multiband RF filter bank is a key component in it. Contour-mode resonators are receiving increased attention for a multiband filter solution, because their resonance frequency is mainly determined by their size and shape, which are defined by lithography. However, spurious responses, including flexural vibration, are also excited due to the thin structure of the devices. To improve resonator performance and suppress spurious modes, visual observation with a laser probe system is very effective. In this paper, we prototyped a mechanically coupled Disk-array filter, which consists of a silicon Disk and two Disk-type resonators of higher-order wineglass mode, and observed its vibration modes using a high-frequency laser Doppler vibrometer (UHF-120, Polytec, Inc.). It was confirmed that the higher-order wineglass mode vibration included a compound displacement, and that its out-of-plane vibration amplitude was much smaller than that of other flexural spurious modes. The observed vibration modes were compared with FEM (Finite Element Method) simulation results. In addition, it was also confirmed that fabrication error (e.g., misalignment) induced asymmetric vibration. © 2012 Wiley Periodicals, Inc. Electron Comm Jpn, 95(5): 33-41, 2012; Published online in Wiley Online Library (). DOI 10.1002/ecj.10406 [ABSTRACT FROM AUTHOR]

  • vibration mode observation of Piezoelectric Disk type resonator by high frequency laser doppler vibrometer
    Ieej Transactions on Electronics Information and Systems, 2011
    Co-Authors: Masayoshi Esashi, Hiroshi Harada, Takeshi Matsumura, Shuji Tanaka
    Abstract:

    For future mobile phones based on cognitive radio technology, a compact multi-band RF front-end architecture is strongly required and an integrated multi-band RF filter bank is a key component in it. Contour-mode resonators are receiving increased attention for a multi-band filter solution, because its resonant frequency is mainly determined by its size and shape, which are defined by lithography. However, spurious responses including flexural vibration are also excited due to its thin structure. To improve resonator performance and suppress spurious modes, visual observation with a laser probe system is very effective. In this paper, we have prototyped a mechanically-coupled Disk-array filter, which consists of a Si Disk and 2 Disk-type resonators of higher-order wine-glass mode, and observed its vibration modes using a high-frequency laser-Doppler vibrometer (UHF-120, Polytec, Inc.). As a result, it was confirmed that higher order wine-glass mode vibration included a compound displacement, and that its out-of-plane vibration amplitude was much smaller than other flexural spurious modes. The observed vibration modes were compared with FEM (Finite Element Method) simulation results. In addition, it was also confirmed that the fabrication error, e.g. miss-alignment, induced asymmetric vibration.

  • Selective mode excitation of Piezoelectric Disk-type resonator by electrode pattern definition
    2010 IEEE International Ultrasonics Symposium, 2010
    Co-Authors: Takeshi Matsumura, Masayoshi Esashi, Hiroshi Harada, Florian Thalmayr, Ken-ya Hashimoto, Shuji Tanaka
    Abstract:

    Contour-mode Piezoelectric MEMS resonators have been widely studied as one of potential components for future multi-band RF solution based on cognitive radio technology, because its resonant frequency is generally determined by the size and shape. To apply them to applications at frequency of higher than hundreds MHz, a specific higher mode should be strongly excited. However, it is often difficult, because the higher order vibration is a compound mode including radial and rotational displacements. In this study, the displacement distributions of higher order wine-glass modes of Disk-type resonators were derived from FEM modal analysis. Then, mechanically-coupled Disk-array filters with baseball-type and doughnut-type electrodes were fabricated and tested. Using the doughnut-type electrodes, (2. 6) mode was selectively excited, and a filter characteristic at a center frequency of 500.3 MHz was obtained. It was numerically and experimentally confirmed that a well-designed electrode pattern enhanced a specific vibration mode and suppressed other modes by comparing different electrode patterns.

C. Yang - One of the best experts on this subject based on the ideXlab platform.

  • Valveless micropump with acoustically featured pumping chamber
    Microfluidics and Nanofluidics, 2010
    Co-Authors: S. S. Wang, X. Y. Huang, C. Yang
    Abstract:

    This article presents a new design of a valveless micropump. The pump consists of a nozzle-shaped actuation chamber with acoustic resonator profile, which functions as both pumping chamber and flow rectification structure. The pump is fabricated by lamination of layers made of polymethyl-methacrylate (PMMA) and dry adhesives, and is driven by a Piezoelectric Disk. The performance of the pump has been studied by both experimental characterization and numerical simulations. Both the experimental and numerical results show that the pump works well at low frequencies of 20–100 Hz to produce relatively high backpressures and flowrates. Moreover, the numerical simulations show that in the pumping frequency range, the flow patterns inside the chamber are found to be asymmetric in one pumping cycle so as to create a net flowrate, while outside the pumping frequency range, the flow patterns become symmetric in the pumping cycle. The pumping frequency can be shifted by modifying the pump configuration and dimensions. The pump is suitable for microfluidic integrations.