A piezoelectric dispenser has been fabricated based on the idea of a piezoelectric-metal-cavity (PMC) actuator. The PMC actuator consists of a metal ring sandwiched between two identical piezoelectric unimorphs. The radial contraction of the piezoelectric ceramic is converted into a flextensional motion of the unimorph, causing a large flexural displacement in the center part of the actuator. W...

This paper proposes a design for a precision positioning miniature walking robot using piezoelectric unimorph actuators. The theoretical working equations of a uniform piezoelectric unimorph beam are derived based on the linear piezoelectric relations, Hamilton’s principle, and Euler-Bernoulli beam equation. The modal superposition method is used to determine the response of the forced transver...

The piezoelectric material selection and the circuit design in vibrational energy harvesting are discussed. The performances of the energy-harvesting unimorph devices that captured frequencies of 60 Hz by using piezoelectric PZT-based and BT-based ceramics were evaluated. Output voltages and power from the devices depend on the amplitude and the frequency of the oscillations, and depend on the ...

Piezoelectric diaphragms are used as synthetic jets because of their size, rapid time response, and relatively low power consumption. Among the piezoelectric diaphragms used are unimorphs and Bimorphs. In this study, a bimorph diaphragm, a thin Unimorph pre-stressed device and a Radial Field Diaphragm (RFD) are compared. A bimorph consists of two bonded PZT discs, a thin Unimorph pre-stressed d...

In this paper at first introduced constituent equations for piezoelectric and then by the help of this equations, internal energy of hinged-hinged piezoelectric multilayer beam was computed. Then by the principle of minimum potential energy and Rayleigh -Ritz method the bending curvature equation of hinged-hinged piezoelectric multilayer beam under concentrated moment, concentrated force, unifo...

We have developed, manufactured and tested a unimorph deformable mirror for space applications based on piezoelectric actuation. The mirror was designed for the correction of low-order Zernike modes with a stroke of several tens of micrometers over a clear aperture of 50 mm. It was successfully tested in thermal vacuum, underwent lifetime tests, and was exposed to random vibrations, sinusoidal ...

The effect of the temperature variation on a unimorph piezoelectric cantilever is studied. Its influences on the thermal expansion, the piezoelectric constant, the transient part and the creep are experimentally analyzed. Afterwards, a H∞ controller is synthesized in order to reject the thermal disturbance and to reach performances required in micromanipulation. Finally, the closed-loop experim...

An intra-cavity adaptive mirror is required to compensate for time-dependent phase aberrations to the laser beam, such as those caused by thermal lensing. A piezoelectric unimorph design can provide a small, low-cost deformable mirror for this application. The unimorph consists of a metallic disc, with a mirror finish, bonded to a piezoelectric disc. In adaptive optics the deformations that the...

This research seeks to develop a novel branch of materials systems called Distributed Intelligent Materials Systems (DIMS) which incorporate actuation, sensing, electronics and intelligence as inherent parts of the material structure. A microcantilever optical switch is fabricated as a concept demonstrator with Gallium nitride (GaN) as host material. GaN has several material characteristics whi...