We investigated the dependence of electromechanical coupling and the piezoelectric response of a micromachined Pb(Zr₀.₅₂Ti₀.₄₈)O₃ (PZT) diaphragm on its curvature by observing the impedance spectrum and central deflection responses to a small AC voltage. The curvature of the diaphragm was controlled by applying air pressure to its back. We found that a depolarized flat diaphragm does not initia...

this paper presents a mathematical model for the vibration analysis of a three-component piezoelectric force sensor. the cubic theory of weakly nonlinear electroelasticity is applied to the model for describing the electromechanical coupling effect in the piezoelectric sensing elements which operate in thickness-shear and thickness-stretch vibration modes. hamilton's principle is used to d...

The electrokinetic effect in a fluid-saturated porous rock is defined as the coupling and conversion between seismic and electric energies. When seismic waves propagate through a fluid-saturated formation and cause a pore fluid-flow relative to the solid matrix, the motion of the cations in the fluidflow forms a streaming electrical current and induces an electromagnetic wave at any discontinuo...

The role of pressor sympathetic reflexes in circulatory control was investigated in conscious dogs. Animals were previously instrumented with a 6- to 8-cm rigid core cannula covered by an inflatable rubber cylinder in the thoracic aorta, a pressure catheter implanted in the aorta above the cannula, and a second catheter inserted into the aorta below the cannula through a femoral artery. Two pie...

Piezoelectric ceramic actuators have wide application prospects in precision positioning and measurement technology, but its hysteresis characteristics cause a lot of restrictions to their applications. To solve this problem, this paper summary the hysteresis characteristic of piezoelectric ceramics, and collect the data through the experiment, analyze and research the piezoelectric ceramic hys...

Pressure-electric (hydrostatic piezoelectric) measurements are reported on bookshelf textures of a ferroelectric smectic-C (Sm C*) liquid crystal with a glass transition. The continuous variation of a partially fluid state to the solid glass enables one to trace how the piezoelectric effect depends on the consistency of the material. It was observed that in the Sm C* samples with poled glass th...

A weakly-singular form of the piezoelectric boundary integral equation (BIE) formulation is introduced in this paper, which eliminates the calculation of any singular integrals in the piezoelectric BIE. The crucial question of whether or not the piezoelectric BIE will degenerate when applied to crack and thin shell-like problems is discussed. It can be shown analytically that the conventional B...

Sensors and actuators based on piezoelectric ceramics are finding an increasingly large variety of applications under a very wide range of environmental conditions and applied signals. Some actuator applications require the piezoelectric materials to support large mechanical loads and produce high strain output. In order to accomplish this requirement of higher strains, large electric fields mu...

The active vibration control of laminated composite plates using distributed piezoelectric sensors and actuators (Fig. 1) is studied numerically with a higher-order finite element method (FEM). Reddy’s simplified higher-order theory for transverse shear deformation, which is found to be much more accurate for both thin and thick composite plates as compared with other theories, is employed for ...

The usefulness of most high technology devices such as cell phones, computers, and sensors is limited by the storage capacity of batteries. In the future, these limitations will become more pronounced as the demand for wireless power outpaces battery development which is already nearly optimized. Thus, new power generation techniques are required for the next generation of wearable computers, w...