Underwater acoustic transducers often include a stack of thickness polarized piezoelectric material pieces of alternating polarity interspersed with electrodes and bonded together. The stack is normally much shorter than a quarter wavelength at the fundamental resonance frequency, so that the mechanical behavior of the transducer is not affected by the segmentation. When the transducer bandwidt...

Power supply is a bottle-neck problem of wireless micro-sensors, especially where the replacement of batteries is impossible or inconvenient. Now piezoelectric material is being used to harvest vibration energy for self-powered sensors. However, the geometry of a piezoelectric cantilever beam will greatly affect its vibration energy harvesting ability. This paper deduces a remarkably precise an...

This paper relates to vibration control using passive electrical shunt circuits. However, the vibration shunt control efficiency relies on the optimization of the vibration energy transfer between a structure and a Lead-Zirconate-Titanate (PZT) piezoelectric ceramic material. The problem is further complicated by the material composition of the substrate or host material the PZT is coupled to. ...

Piezoelectric energy harvester scavenges mechanical vibrations and generates electricity. Researchers have strived to optimize the electromechanical structures and to design necessary external power management circuits, aiming to deliver high power and rectified outputs ready for serving as batteries. Complex deformation of the mechanical structure results in charges with opposite polarities ap...

Current models of non-linear electromechanical behaviours of piezoactuators are mostly intended for actuator configurations where the strain of the piezoelectric material is directly used as the linear output. On the other hand, in the design of piezoactuators, there exist non-trivial configurations where the internal strains of the piezoelectric materials manifest externally in the form of ben...

Electrical energy can be harvested from the wind using flag-like membranes (termed piezoelements or bimorphs) composed of flexible piezoelectric materials. The flapping of the membrane caused by the wind induces bending stresses which generate a voltage across electrodes positioned on the surfaces of the material via the piezoelectric properties of the material. The best results to date using P...

ÐThe response of lead zirconate titanate and barium titanate piezoelectric ceramics to spherical microindentation was investigated. Force vs penetration depth curves obtained from instrumented indentation reveal that the indentation sti€ness depends on the material condition (i.e. poled vs unpoled) and the type of indentor (i.e. electrically conducting vs insulating). Good agreement was found b...

In this work, the problem of a curved functionally graded piezoelectric (FGP) actuator with sandwich structure under electrical and thermal loads is investigated. The middle layer in the sandwich structure is functionally graded with the piezoelectric coefficient g31 varying continuously along the radial direction of the curved actuator. Based on the theory of linear piezoelectricity, analytica...

Recent work has demonstrated piezoelectric behavior in voided polymers. It is thought that the piezoelectricity results from the creation of space charges bordering the voids when the material is exposed to an electric field in excess of the breakdown strength. The resulting voided piezoelectric material is more flexible than conventional piezoelectric ceramics, and may be far less expensive to...

AN ARTICLE by Belušič and Zupančič (1) described the construction of a finger pulse sensor using a singing greeting card beeper. We felt that this beeper made of piezoelectric material could be easily modified to function as a respiratory belt transducer to monitor respiratory movements. Commercially available respiratory belt transducers, such as Pneumotrace (http:// www.adinstruments.com/prod...