Electromechanical field concentrations near the electrode tip in partially poled multilayer piezo-film actuators

2009 ◽  
Vol 18 (8) ◽  
pp. 085020 ◽  
Author(s):  
Yasuhide Shindo ◽  
Fumio Narita ◽  
Mitsuru Hirama
Keyword(s):  
Electromechanical Field

Electromechanical field effects in InAs/GaAs quantum dots based on continuum k→·p→ and atomistic tight-binding methods

2021 ◽  
Vol 197 ◽  
pp. 110678
Author(s):  
Daniele Barettin ◽  
Alessandro Pecchia ◽  
Matthias Auf der Maur ◽  
Aldo Di Carlo ◽  
Benny Lassen ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Tight Binding ◽  
Field Effects ◽  
Electromechanical Field

Lateral Stress Effect on Fracture Quantities of a Crack in a Piezoelectric Medium

2007 ◽  
Vol 348-349 ◽  
pp. 957-960
Author(s):  
Erasmo Viola ◽  
Claudia Belmonte ◽  
Giuseppe Viola
Keyword(s):  
Analytical Approach ◽  
Decomposition Theorem ◽  
Piezoelectric Medium ◽  
Stress Effect ◽  
Lateral Stress ◽  
Intensity Factors ◽  
Field Equations ◽  
Piezoelectric Body ◽  
Electroelastic Fields ◽  
Electromechanical Field

The aim of this paper is to seek the solution to the electromechanical field equations for a cracked linear piezoelectric body using an analytical approach which is based on the decomposition theorem of linear algebra. The electroelastic fields around the crack tip are given. The energy release rate is written in terms of those fields intensity factors.

Experimental and numerical analysis of the indium-content on the internal electromechanical field in GaN-based light-emitting diodes

Optik ◽  
2018 ◽  
Vol 172 ◽  
pp. 1193-1198 ◽  
Author(s):  
Usman Muhammad ◽  
Nabila Nawaz ◽  
Kiran Saba ◽  
Khasan Karimov ◽  
Nazeer Muhammad
Keyword(s):  
Numerical Analysis ◽  
Light Emitting Diodes ◽  
Indium Content ◽  
Light Emitting ◽  
Electromechanical Field

The Dynamic Electromechanical Behaviour of Advanced Composites Incorporating Piezoelectric Fibres

1999 ◽  
Author(s):  
X. D. Wang
Keyword(s):  
Original Problem ◽  
Electrical Response ◽  
Local Stress ◽  
Comprehensive Treatment ◽  
Loading Frequency ◽  
Algebraic Equations ◽  
Linear Algebraic Equations ◽  
Consistent Manner ◽  
Material Mismatch ◽  
Electromechanical Field

Abstract This paper provides a comprehensive treatment of the electromechanical behaviour of fibre reinforced piezoelectric composites under steady-state dynamic loading. The composites are modelled as two-dimensional media with interacting piezoelectric inhomogeneities. The original problem is decomposed into single inhomogeneity subproblems, which are solved by using Fourier expansions. The solutions of these subproblems are then summed up in a consistent manner to provide a system of linear algebraic equations, from which the dynamic electromechanical field in the composites can be determined. Numerical examples are provided to show the effect of the interaction between piezoelectric fibres, the material mismatch and the loading frequency upon the dynamic local stress field and electrical response of the composites.

scholarly journals The Effect of Defects in Piezoelectric Composite Half-Planes with Surface Electrodes

2020 ◽  
Vol 4 (2) ◽  
pp. 43
Author(s):  
Jacob Aboudi
Keyword(s):  
Fourier Transform ◽  
Boundary Value Problem ◽  
Half Plane ◽  
Iterative Procedure ◽  
Boundary Value ◽  
Piezoelectric Composite ◽  
Rectangular Region ◽  
Surface Electrodes ◽  
The Fourier Transform ◽  
Electromechanical Field

An analysis for the prediction of the electromechanical field in composite piezoelectric half-planes with attached surface electrode is presented. The composite half-planes are composed of distinct constituents and may include internal defects in various locations. The solution is carried out in a sufficiently large rectangular region, the boundary conditions of which are obtained from the corresponding solution of a homogeneous piezoelectric half-plane. This is followed by the application of the discrete Fourier transform at the domain of which a boundary-value problem is formulated. The solution of this boundary-value problem, followed by the inversion of the Fourier transform, provides, in conjunction with an iterative procedure, the electromechanical field at any point of the rectangular region. Applications are given for a piezoelectric half-plane with defects in the form of a cavity and of short and semi-infinite cracks as well as of a periodically bilayered composite with a crack in one of its layers.

scholarly journals Enhanced Internal Quantum Efficiency of Bandgap-Engineered Green W-Shaped Quantum Well Light-Emitting Diode

2018 ◽  
Vol 9 (1) ◽  
pp. 77 ◽  
Author(s):  
Muhammad Usman ◽  
Urooj Mushtaq ◽  
Dong-Guang Zheng ◽  
Dong-Pyo Han ◽  
Muhammad Rafiq ◽  
...  
Keyword(s):  
Quantum Well ◽  
Quantum Efficiency ◽  
Recombination Rate ◽  
Auger Recombination ◽  
Light Emitting Diode ◽  
Internal Quantum Efficiency ◽  
Green Light ◽  
Light Emitting ◽  
Hole Confinement ◽  
Electromechanical Field

To improve the internal quantum efficiency of green light-emitting diodes, we present the numerical design and analysis of bandgap-engineered W-shaped quantum well. The numerical results suggest significant improvement in the internal quantum efficiency of the proposed W-LED. The improvement is associated with significantly improved hole confinement due to the localization of indium in the active region, leading to improved radiative recombination rate. In addition, the proposed device shows reduced defect-assisted Shockley-Read-Hall (SRH) recombination rate as well as Auger recombination rate. Moreover, the efficiency rolloff in the proposed device is associated with increased built-in electromechanical field.

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
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Resonant Frequency ◽  
Electric Fields ◽  
Lead Zirconate Titanate ◽  
Microelectromechanical Systems ◽  
Thick Films ◽  
Lead Zirconate ◽  
Electromechanical Field ◽  
Element Method

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.

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