Dynamic Electromechanical Field Concentrations Near Electrodes in Piezoelectric Thick Films for the Design of MEMS Mirrors

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
Yasuhide Shindo ◽  
Fumio Narita ◽  
Koji Sato

This paper studies the dynamic electromechanical response of piezoelectric mirrors driven by piezoelectric lead zirconate titanate (PZT) thick films both numerically and experimentally. The resonant frequency and the mirror tilt angle of piezoelectric mirrors under ac electric fields were analyzed by three-dimensional finite element method. The dynamic electromechanical field concentrations due to electrodes were also simulated and the results were discussed in detail. The mirrors consisted of four partially poled PZT unimorphs. The resonant frequency was then measured, and a comparison was made between the analysis and the experiment. The finite element method is shown to be capable of estimating the electromechanical field concentrations in the PZT films, making it a useful tool for designing future microelectromechanical systems (MEMS) mirrors.

2019 ◽  
Vol 11 (7) ◽  
pp. 168781401985368 ◽  
Author(s):  
Jesús Acevedo-Mijangos ◽  
Antonio Ramírez-Treviño ◽  
Daniel A May-Arrioja ◽  
Patrick LiKamWa ◽  
Héctor Vázquez-Leal ◽  
...  

We present a resonant magnetic field sensor based on microelectromechanical systems technology with optical detection. The sensor has single resonator composed of two orthogonal silicon beams (600 µm × 26 µm × 2 µm) with an integrated mirror (50 µm × 34 µm × 0.11 µm) and gold tracks (16 µm × 0.11 µm). The resonator is fabricated using silicon-on-insulator wafer in a simple bulk micromachining process. The sensor has easy performance that allows its oscillation in the first bending vibration mode through the Lorentz force for monitoring in-plane magnetic field. Analytical models are developed to predict first bending resonant frequency, quality factor, and displacements of the resonator. In addition, finite element method models are obtained to estimate the resonator performance. The results of the proposed analytical models agree well with those of the finite element method models. For alternating electrical current of 30 mA, the sensor has a theoretical linear response, a first bending resonant frequency of 43.8 kHz, a sensitivity of 46.1 µm T−1, and a power consumption close to 54 mW. The experimental resonant frequency of the sensor is 53 kHz. The proposed sensor could be used for monitoring in-plane magnetic field without a complex signal conditioning system.


2020 ◽  
Vol 978 ◽  
pp. 337-343
Author(s):  
Neelam Mishra ◽  
Chaitanya Shah ◽  
Kaushik Das

Polyvinylidene fluoride (PVDF) – Lead Zirconate Titanate (PZT) is a polymer composite that is becoming increasingly popular in micro-scale sensors and actuators because of its unique properties such as high flexibility, low density and high piezoelectric constants. However, lead-based piezoceramics, despite their superior properties, are toxic and are known to damage the environment, and as such a conscientious effort is being made by the scientific community towards replacing lead-containing piezoceramics with environmentally-friendlier and lead-free piezoceramics. Barium Titanate (BaTiO3) is one such piezoceramics that is widely studied today to be a potential replacement of PZT in many applications. As such, in this work, effort has been made to predict the effective mechanical, dielectric and piezoelectric properties of PVDF-BaTiO3 composite system using Finite Element Method (FEM). Kinematic Uniform Boundary Conditions (Displacement and Voltage) are used for this analysis. For evaluation of the effective material constants of the composite, several types of representative volume elements are considered. The effects of volume fraction, effect of the size of the micro-particles i.e. mono-modal versus multi-modal size distribution, effect of periodic versus quasi-random distribution of microparticles in the matrix, the effect of clustering of the particles, effect of orientation of the microparticles i.e. unidirectional or randomly oriented are discussed. Finally, a comparison of properties between PVDF-PZT and PVDF-BaTiO3 is made, so as to see whether PVDF-BaTiO3 can be a potential replacement for PVDF-PZT composite.


2013 ◽  
Vol 278-280 ◽  
pp. 315-318
Author(s):  
Ming Li Zhao ◽  
Bo Zhao ◽  
Yu Qing Wang

The node position of amplitude transformer was determined by the finite element method, and the flange was designed at the nod position for conveniently installation. By the finite element software, the amplitude transformer with flange was optimized and dressed, and its structural parameters were determined. During the actual manufacturing process, it was used impedance analyzer to test its vibration performance, the testing results show that this system vibration performance is good, its resonant frequency is 34.771kHz, anti-resonant frequency is 35.008kHz. The above-mentioned results are very much coincided with the system natural frequency of 34.893kHz which is drew by finite element method. Compared to the traditional dressing this method has many advantages such as convenience, green, environmental protection, low cost and others.


2020 ◽  
Author(s):  
Dang Quoc Vuong ◽  
Bui Minh Dinh

Modelling of realistic electromagnetic problems is presented by partial differential equations (FDEs) that link the magnetic and electric fields and their sources. Thus, the direct application of the analytic method to realistic electromagnetic problems is challenging, especially when modeling structures with complex geometry and/or magnetic parts. In order to overcome this drawback, there are a lot of numerical techniques available (e.g. the finite element method or the finite difference method) for the resolution of these PDEs. Amongst these methods, the finite element method has become the most common technique for magnetostatic and magnetodynamic problems.


2014 ◽  
Vol 852 ◽  
pp. 624-628 ◽  
Author(s):  
Yuan Sheng Zheng ◽  
Yong Chun Zeng

Jet repulsion is the most difficult issue in the multineedle electrospinning process. This study aims at reducing the jet pulsion by designing the spinneret. Three different multijet electrospinning configutations are used to study the jet repulsion in multijet electrospinning process. The experimental results shows that adding a PTFE cylinder to the traditional multineedle electrospinning setup can reduce the jet repulsion, but the diameter and irregularity of the resultant fiber other increased. A needleless electrospinning setup using a multihole plate to replace the needles can reduce jet repulsion effectively, reduce fiber diameter and irregularity as well. And the electric fields of the three electrospinning configurations are simulated by finite element method to explain the experiment results.


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