The active vibration control of smart plate equipped with patched piezoelectric sensors and actuators is presented in this study. An equivalent single layer third order shear deformation theory is employed to model the kinematics of the plate and to obtain the shear strains. The governing equations of motion are derived using extended Hamilton’s principle. Linear variation of electric potential...

This paper focuses on the design, fabrication and characterization of unimorph actuators for a microaerial flapping mechanism. PZT-5H and PZN-PT are investigated as piezoelectric layers in the unimorph actuators. Design issues for microaerial flapping actuators are discussed, and criteria for the optimal dimensions of actuators are determined. For low power consumption actuation, a square wave ...

We report on a novel microfabrication method to fabricate aluminum nitride (AlN) piezoelectric microstructures down to 2 microns size by a surface micromachining process. Highly c-axis oriented AlN thin films are deposited between thin Cr electrodes on polysilicon structural layers by rf reactive sputtering. The top Cr layer is used both as a mask to etch the AlN thin films and as an electrode ...

Photoreflection and photoluminescence spectroscopies have been used to identify details of the electronic bandstructure in GaInN/GaN strained heterostructures and multiple quantum well structures. Franz-Keldysh oscillations in the ternary layers are identified in both systems revealing large piezoelectric fields of 240 kV/cm (x=0.079, thin film) and 0.65 MV/cm (x=0.187). From spatially resolved...

We have investigated the effects of different p-type polymer layers on the piezoelectric potential from ZnO nanowire (NWs) grown on silver (Ag) coated silicon (Si) substrate by the low temperature chemical synthesis method. Piezoelectric measurement was done by a conductive atomic force microscope (AFM). In the case of the poly(3,4ethylenedioxythiophene-Tosylate (PEDOT-Tos), the output voltage ...

Piezoelectric actuators (PEAs) have been widely used in micro- and nanopositioning applications due to their fine resolution, rapid responses, and large actuating forces. However, a major deficiency of PEAs is that their accuracy is seriously limited by hysteresis. This paper presents adaptive model predictive control technique for reducing hysteresis in PEAs based on autoregressive exogenous m...

Active structures, used for manufacture satellites, robots or others industrial processes, are subjected to external disturbances inducing oscillation of the structure. With the technical progress of the last few years, piezoelectric sensors and actuators are now used to control such structures. The aim of our research is to develop a control algorithm embedded on a DSP board in order to stabil...

An analytical approach is proposed in the reduction of free edge peeling stresses of laminated composites using active piezoelectric layers. The approach is the extended Kantorovich method which is an iterative method. Multiterms of trial function are employed and governing equations are derived by taking the principle of complementary virtual work. The solutions are obtained by solving a gener...

This paper addresses modeling of guided-wave excitation by surface-bonded piezoelectric wafer transducers in multi-layered composite plate structures. Each of the individual layers is assumed to have unidirectional fibers in an epoxy matrix and is modeled as being transversely isotropic. The piezoelectric actuators are modeled as causing shear traction along their edges on the plate surface and...

The structural properties of r.f. planar magnetron sputtered ZnO films are studied as a function of deposition parameters: substrate type, substrate temperature, sputter gas pressure, growth rate and sputtering power. These films are applied as piezoelectric transducers in micromechanical sensors and actuators. The electric properties, and consequently the piezoelectric behaviour, depend strong...