abstract: the main aim of the vibration energy harvesters is to locally power autonomous devices such as wireless sensors. generally, power levels are low and the environmental benefit of the technology is to replace batteries rather than saving energy per se. piezoelectric vibrational energy harvesters are usually inertial mass based devices, where a cantilever beam with a piezoelectric outer ...

We integrated a piezoelectric sensing layer lamina containing liquid crystals (LC) and spiropyran (SP) in a LC/SP mixture to create an optically reconfigurable modal sensor for a cantilever beam. The impedance of this LC/SP lamina was decreased by UV irradiation which constituted the underlying mechanism to modulate the voltage externally applied to the piezoelectric actuating layer. Illuminati...

Hydrogen exposure of III-V HEMTs has been shown to cause a threshold voltage shift, AVT. This is a serious reliability concern. This effect has been attributed to a H-induced piezoelectric effect. Formation of TiHX expands the Ti layer in the gate, causing mechanical stress in the underlying semiconductor. This induces piezoelectric charge in the heterostructure underneath the gate that shifts ...

Direct current (DC) piezoelectric power generator is promising for the miniaturization of a power package and self-powering of nanorobots and body-implanted devices. Hence, we report the first use of two-dimensional (2D) zinc oxide (ZnO) nanostructure and an anionic nanoclay layer to generate piezoelectric DC output power. The device, made from 2D nanosheets and an anionic nanoclay layer hetero...

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...

for an Invited Paper for the MAR09 Meeting of The American Physical Society Flexoelectricity in nanostructures PRADEEP SHARMA, University of Houston Crystalline piezoelectric dielectrics electrically polarize upon application of uniform mechanical strain. Inhomogeneous strain, however, locally breaks inversion symmetry and can potentially polarize even non-piezoelectric (centrosymmetric) dielec...

in this paper, a nonlinear free vibration analysis of thin annular functionally graded (fg) plate integrated with two uniformly distributed actuator layers made of piezoelectric (pzt4) material on the top and bottom surfaces of the annular fg plate is presented based on kirchhoff plate theory. the material properties of the fgm core plate are assumed to be graded in the thickness direction acco...

In this paper, the free vibration analysis of sandwich micro beam with piezoelectric layers based on the modified couple stress and surface elasticity theories are investigated. The Hamilton’s principle is employed to derive the sandwich micro beam with piezoelectric based on modified couple stress theory incorporating with Gurtin- Murdoch surface theory. The generalized differential quadrature...

In this paper, the shape influence of piezoelectric beams including triangle, trapezoid, rectangle, inverted trapezoid, convex parabola, concave parabola, and comb-shaped (a combination of two triangular beams with a connector of 4 mm length) are addressed and analyzed by FEM. The analysis is performed for a bimorph piezoelectric beam. The analyzed parameters include the beam length, thickness ...

In this paper, we present a new approach to the fabrication of integrated silicon-based piezoelectric diaphragm-type biosensors by using sodium potassium niobate-silver niobate (0.82KNN-0.18AN) composite lead-free thin film as the piezoelectric layer. The piezoelectric diaphragms were designed and fabricated by micro-machining technology and chemical solution deposition. The fabricated device w...