A Gated Two-Frequency Two-Mode Method for Piezoelectric Motorization

2021 ◽  
pp. 1-23
Author(s):  
Yu-Hsiang Hsu ◽  
Tsung-Yu Chu ◽  
Zi-Xun Lin ◽  
Chih-Kung Lee
Keyword(s):  
Phase Difference ◽  
Traveling Waves ◽  
Numerical Data ◽  
Voltage Ratio ◽  
Resonant Modes ◽  
Finite Structures ◽  
Bending Mode ◽  
Mode Method ◽  
Moving Direction ◽  
Driving Signal

Abstract In this study, we present a new driving method to generate traveling waves in a finite plate for the application of piezoelectric motorizations. Due to resonant modes which dominate the vibration of finite structures, methods to reduce resonant effects such as using an electric sinker or driving at a non-resonant frequency, have been reported. To take the advantage of natural resonance and to increase driving efficiency, a new method entitled a gated two-frequency-two-mode (G-TFTM) was developed. A piezoelectric bimorph of 1.1g weight with two rectangular actuators was implemented to verify the design concept. One actuator was operated at a first bending mode and the other actuator operated at a second bending mode with phase difference. The driving signal was gated to generate an intermittent excitation to provide a periodic propulsion. To determine the profile of the induced traveling wave, an analytical solution was derived and a numerical model was used. Using these design tools, we experimentally verified that traveling waves can be generated using a G-TFTM method. A 0.1 g object can be moved at a speed of 3.31 mm/s under the condition of a 70-to-20 voltage ratio and a 137-degree phase difference. The moving direction was found to be reversed by changing the phase to -43 degrees. The experimental and numerical data are detailed in this paper to demonstrate the feasibility of this G-TFTM method.

scholarly journals Generation of Linear Traveling Waves in Piezoelectric Plates in Air and Liquid

Micromachines ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 283 ◽  
Author(s):  
Alex Díaz-Molina ◽  
Víctor Ruiz-Díez ◽  
Jorge Hernando-García ◽  
Abdallah Ababneh ◽  
Helmut Seidel ◽  
...  
Keyword(s):  
Phase Velocity ◽  
Numerical Simulations ◽  
Traveling Waves ◽  
Traveling Wave ◽  
Microelectromechanical Systems ◽  
Laser Doppler Vibrometry ◽  
Resonant Modes ◽  
Silicon Cantilever ◽  
Mems Technology ◽  
Driving Signal

A micro- to milli-sized linear traveling wave (TW) actuator fabricated with microelectromechanical systems (MEMS) technology is demonstrated. The device is a silicon cantilever actuated by piezoelectric aluminum nitride. Specifically designed top electrodes allow the generation of TWs at different frequencies, in air and liquid, by combining two neighboring resonant modes. This approach was supported by analytical calculations, and different TWs were measured on the same plate by laser Doppler vibrometry. Numerical simulations were also carried out and compared with the measurements in air, validating the wave features. A standing wave ratio as low as 1.45 was achieved in air, with a phase velocity of 652 m/s and a peak horizontal velocity on the device surface of 124 μm/s for a driving signal of 1 V at 921.9 kHz. The results show the potential of this kind of actuator for locomotion applications in contact with surfaces or under immersion in liquid.

Development of a two-dimensional piezoelectric traveling-wave generator

2020 ◽  
pp. 1045389X2094394
Author(s):  
Yu-Min Lin ◽  
Yu-Hsiang Hsu ◽  
Wen-Chun Su ◽  
Yuan-Ting Kao ◽  
Chih-Kung Lee
Keyword(s):  
Traveling Waves ◽  
New Method ◽  
Two Dimensional ◽  
Resonant Frequencies ◽  
Specific Direction ◽  
Directional Movement ◽  
Bending Mode ◽  
Wave Generator ◽  
Bending Modes ◽  
Four Electrodes

In this article, we present a new method to control the direction of traveling waves in either an x-direction or y-direction on a two-dimensional square plate. The core structure was composed of a piezoelectric serial bimorph with four electrodes. Each electrode was spatially designed to activate one of the bending modes and which included the ability to reduce adjacent modes and minimize interference. Our new method differs from other reported methods in that the four electrodes were driven at designated resonant frequencies. In our wave generator, different driving amplitudes and phases were applied to induce the traveling waves to propagate in a specific direction. To design the directional movement and to better understand the pattern of induced traveling waves, an analytical solution was derived to assist in the design of the four driving electrodes. Using our newly developed analytical method, traveling waves can be controlled to travel in either the x-direction or y-direction using two different sets of electrodes, where each electrode can be driven at a specific but different bending mode. We found that both the voltage ratio and phase difference between the two driving electrodes are important factors for optimization.

On Vibrating Traveling Waves Actuation, Sensing, and Tuning in Finite Structures

2006 ◽  
Author(s):  
Ran Gabay ◽  
Izhak Bucher
Keyword(s):  
Traveling Waves ◽  
Traveling Wave ◽  
Impedance Matching ◽  
Parametric Method ◽  
Normal Modes ◽  
Practical Implementation ◽  
Original Form ◽  
Impedance Change ◽  
Finite Structures ◽  
Active Impedance

This work is concerned with a method to generate pure traveling vibration waves in finite structures. Using progressing deformations, i.e. waves, is not common when dealing with forced vibration since structures are naturally vibrating in their, naturally occurring, normal modes. Indeed, natural vibration modes can be referred to standing waves. Since a structure does not lend itself to a traveling wave vibration, the generation of traveling waves in a structure becomes a challenging task. The boundary conditions or external forces must be carefully tuned in an iterative process that necessitates measurement and identification of the traveling and standing wave components. In this work, a method to generate and measure traveling waves is presented for one and two-dimensional structures. Both analytical and experimental results are provided here. A traveling wave is a disturbance that propagates away from its source carrying energy along its path. In finite structures, a wave hitting a boundary experiences an impedance change that gives rise to a partial reflection, thus distorting its original form. For a pure traveling wave to occur, the boundary of the structure must be set to match the impedance of the structure, and thus to absorb the disturbance while preventing any reflected wave from the boundaries. Impedance matching can be accomplished by passive or active means. Active impedance matching is obtained by generating a vibrating wave at one end (a source) and 'pumps' it on the other, active absorbing end, often addressed as a sink. Indeed, active impedance matching sometimes referred as the "active sink" method. Special methods must be used to extract the description of the vibrating wave characteristics from the measured vibration efficiently, and possibly in real-time (for control purposes). A parametric method is employed in this work to describe and analyze the wave vibration from measurements. In reality, the theoretical knowledge of how to excite a vibrating traveling wave is not sufficiently accurate to produce traveling waves. Minute manufacturing imperfections, small structural and actuator asymmetry may cause large deviations from pure traveling waves state. It is shown that a tuning process that relies on the measurements but combined with a physical model, should serve as the basis of the practical implementation. Several experiments on a string-like structure are described stressing the physical implications as well as the refined experimental procedure. The actuation techniques, wave identification methods and the tuning procedure of a vibrating traveling wave are described in some detail for the experimental work.

Generating Traveling Vibration Waves in Finite Structures

2008 ◽  
Author(s):  
Ran Gabai ◽  
Izhak Bucher
Keyword(s):  
Traveling Waves ◽  
Traveling Wave ◽  
Normal Modes ◽  
Wave State ◽  
Naturally Occurring ◽  
Finite Structures ◽  
Applied Forces ◽  
Small Model ◽  
External Forces

This work is concerned with a method to generate pure traveling vibration waves in finite structures. Progressing elastic deformations, i.e. waves, are not common in forced vibrating structures since a structure is naturally vibrating in its, naturally occurring, normal modes that are usually referred to standing waves. This makes the generation of traveling waves in a structure a challenging task. In this work, external excitation is applied to the structure in order to create traveling waves in one dimensional structures. Based on a model of the structure and its boundaries, it is possible to calculate, theoretically, the required excitation, in order to generate a pure traveling wave in the structure. This calculation has little merit in practice since small model uncertainties and boundary dynamics effects may alter the generated waves such that they are far from being traveling waves. An iterative in situ method to tune the applied forces, until the desired traveling wave are formed, is presented. This method relays on estimating the current wave-vibrations state in a structure from measurements and tune the external forces toward a pure traveling wave state. An experimental validation of the theory is presented to support the theory.

A 10MHz DC/DC Converter with Zero-Phase Difference Synchronous Driving Signal

2021 ◽  
pp. 1-1
Author(s):  
Yueshi Guan ◽  
Zhenyu Shi ◽  
Chang Liu ◽  
Yijie Wang ◽  
Dian Guo Xu
Keyword(s):  
Phase Difference ◽  
Driving Signal ◽  
Zero Phase

scholarly journals A Tunable Planar Balun with an Isolation Circuit Using Varactors Loaded Coupled Lines

Electronics ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 401
Author(s):  
Shaojun Fang ◽  
Xiaojian Guo ◽  
Hongmei Liu ◽  
Zhongbao Wang
Keyword(s):  
Phase Difference ◽  
Tuning Range ◽  
Frequency Tuning ◽  
Impedance Match ◽  
Flow Diagram ◽  
Coupled Lines ◽  
Mode Method ◽  
Frequency Tunable ◽  
Tunable Frequency ◽  
Planar Balun

In this paper, a frequency tunable planar balun composed of varactors loaded coupled lines (VL-CLs) is presented. By tuning the capacitances of the varactors, a wide frequency tuning range is obtained. Moreover, good impedance match, balanced output ports amplitude, and consistent output ports phase difference (PD) are maintained during the tuning. A detailed theoretical analysis using the signal flow diagram and the even-odd mode method is presented to clarify the characteristics of the proposed balun. To achieve ideal output matching and isolation for the proposed balun, a novel frequency tuned isolation circuit (IsC) is designed and connected to the balun. In theory, a frequency tuning range of 200% can be realized. In practice, due to the limited capacitances of the varactors, a prototype with a tunable frequency of 1.0 GHz ~ 2.0 GHz (66.7%) is designed, fabricated, and measured. The measured results show that more than21 dB of return loss (RL), 180° ± 1.8° of phase difference, 0.43 dB of amplitude imbalance (AP), and 22 dB of isolation are obtained at all tuning center frequencies, agreeing well with the simulated results.

Vehicle Propulsion by Solid State Motion

2014 ◽  
Author(s):  
Lucas Jones ◽  
Josh Spahnie ◽  
Kevin Lefeave ◽  
Charles Haltom ◽  
Adam Underwood ◽  
...  
Keyword(s):  
Phase Difference ◽  
Traveling Waves ◽  
Traveling Wave ◽  
Piezoelectric Actuators ◽  
Underwater Vehicle ◽  
Driving Frequency ◽  
Free Boundary Conditions ◽  
Vehicle Propulsion ◽  
Propulsion Mechanism ◽  
Resonance Frequencies

Traveling waves have shown the potential to transport material and are thus investigated as a propulsion mechanism. Through the use of piezoelectric actuators (PZTs), traveling waves were produced in beams with both free-free and fixed-free boundary conditions. It is shown that traveling waves can be generated by exciting two PZTs at a common frequency with a phase difference between the PZT signals. Experimentation showed the signal that creates the best traveling wave occurs at a driving frequency halfway between adjacent bending resonance frequencies and a phase difference of 90° between both PZTs signals. This has produced traveling waves in fixed-free beams and free-free beams in both air and water as well as for an underwater vehicle. These traveling waves generated useful propulsion in both the fixed-free and free-free beams.

Characterization of Micromachined Seesaw Type Microphone

2013 ◽  
Author(s):  
Byungki Kim ◽  
Paul Phamduy
Keyword(s):  
Phase Difference ◽  
Relative Motion ◽  
Source Localization ◽  
Sound Source ◽  
Arrival Time ◽  
Time Difference ◽  
Sound Source Localization ◽  
Bending Mode ◽  
Flexible Diaphragm

A seesaw type microphone is characterized to study its feasibility for sound source localization. The microphone is composed of a flexible rectangular diaphragm sustained by two torsion-bars. With this structure, the microphone has two main dynamic modes: rocking mode from the twisting of the torsion bars and bending mode from the bending of the flexible diaphragm. Thus, the microphone’s motion is a combination of the two modes. Depending on the frequency of the incident sound and its arrival time difference at each side of the seesaw type microphone, relative motion of both sides of the seesaw type microphone is changed. By measuring relative amplitude and phase of the motion at each side of the microphone, arrival time difference of the sound source at each side can be estimated, and then, localization of the sound source is feasible. In this paper, we present that the microphone shows a significant vibration difference from each side when AC with 45° phase difference is applied to each side of the microphone to mimic the microphone receiving angled incoming sound.

Compact Tri-Band BPF with Controllable Passbands Based on Stubs Loaded Stepped-Impedance Resonators

Frequenz ◽  
2016 ◽  
Vol 70 (5-6) ◽  
Author(s):  
Jin Xu
Keyword(s):  
Bandpass Filter ◽  
Second Order ◽  
Resonant Modes ◽  
Compact Size ◽  
Resonant Behavior ◽  
Mode Method

AbstractIn this paper, a novel second-order tri-band bandpass filter (BPF) is presented by using the first three modes of stubs loaded stepped-impedance resonators (SIRs). The resonant behavior of proposed stubs loaded SIR is analyzed by even-/odd-mode method and parameters sweep, which shows its controllable first three resonant modes. As an example, a second-order tri-band BPF operating at 3.5/5.2/5.8 GHz for WiMax and WLAN applications is designed, fabricated and measured. The fabricated filter has a compact size of 0.21λ

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