نتایج جستجو برای: electromechanical coupling factor

تعداد نتایج: 994233  

Journal: :Ultrasonics 2003
Wenhua Jiang Rui Zhang Bei Jiang Wenwu Cao

The relaxor based ferroelectric (1-x)Pb(Zn(1/3)Nb(2/3))O(3)-xPbTiO(3) and (1-x)Pb(Mg(1/3)Nb(2/3))O(3)-xPbTiO(3) single crystals provided new challenges in property characterization because their extraordinarily large piezoelectric coefficients and electromechanical coupling coefficients. Large errors may occur in some of the derived material constants using conventional characterization techniq...

2017
Michael Schneider Andrew J. Flewitt Enrique Iborra Ulrich Schmid

Film bulk acoustic resonators (FBAR) are promising candidates to replace surface acoustic wave devices as filters or delay lines, but also offer exciting opportunities as biological or gas sensors. In this work, solidly mounted FBARs were manufactured by substituting commonly used pure aluminium nitride (AlN) by scandium doped aluminium nitride (ScAlN) thin films as the piezoelectric layer. The...

2001
Z.-Y. Cheng V. Bharti T.-B. Xu Haisheng Xu T. Mai Q. M. Zhang

High energy electron (1.0±2.55 MeV) irradiation was used to modify the phase transitional behavior of poly(vinylidene ̄uoridetri ̄uoroethylene) (P(VDF-TrFE)) copolymers in an attempt to signi®cantly improve the electromechanical properties of the copolymers. It is found that the copolymers under a proper irradiation treatment exhibit very little room temperature polarization hysteresis and very ...

Journal: :Nanotechnology 2007
Sergei V Kalinin Brian J Rodriguez Stephen Jesse Katyayani Seal Roger Proksch Sophia Hohlbauch Irene Revenko Gary Lee Thompson Alexey A Vertegel

Electromechanical coupling is ubiquitous in biological systems, with examples ranging from simple piezoelectricity in calcified and connective tissues to voltage-gated ion channels, energy storage in mitochondria, and electromechanical activity in cardiac myocytes and outer hair cell stereocilia. Piezoresponse force microscopy (PFM) originally emerged as a technique to study electromechanical p...

2005
Siavash Pourkamali Farrokh Ayazi

This paper, the second of two parts, introduces electrostatic coupling of micromechanical resonators for implementation of high-order narrow-bandwidth bandpass filters. The concept of electrostatic coupling of closely spaced microresonators and its electromechanical modeling is presented. Electrostatic coupling of resonators does not require any distinct physical coupling elements. The electros...

Journal: :Micromachines 2016
Mostafa R. A. Nabawy William J. Crowther

Abstract: Electromechanical coupling defines the ratio of electrical and mechanical energy exchanged during a flexure cycle of a piezoelectric actuator. This paper presents an analysis of the dynamic electromechanical coupling factor (dynamic EMCF) for cantilever based piezoelectric actuators and provides for the first time explicit expressions for calculation of dynamic EMCF based on arrangeme...

2003
N. F. NAUMENKO V. I. CHEREDNICK

ical coupling factor to realize the required bandwidth of the PCS duplexer. So, the SAW duplexer for the PCS with the only steeper characteristics has been developed to eke out its insufficient temperature stability. The PCS duplexers consisting of FBAR (film bulk acoustic resonator) have also been designed as another approach, but their temperature characteristics are not thorough. In this pap...

2016
Azza Z. El Eraky Nesrin M. Handoka Mona Sayed Ghaly Samah Ismail Nasef Nahed A. Eldahshan Ahmed M. Ibrahim Sherein Shalaby

BACKGROUND Juvenile idiopathic arthritis (JIA) is a systemic chronic inflammatory disease. Studies using tissue Doppler imaging (TDI) for the evaluation of cardiac functions of children with JIA are limited. Thus, this study was conducted to evaluate Left ventricular function, left atrial mechanical functions and atrial electromechanical delay in JIA. METHODS This study was carried out as a a...

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