We report on the first successful operation of a cyclic contact scanning force microscope ~SFM! using a self-excited cantilever in liquid. Based on a new structure including a PZT reference pattern and a free-standing PZT cantilever, the piezoelectric self-excitation and self-detection mechanism for a PZT microcantilever was developed successfully. The topography is recorded by measuring the pi...

The effect of mechanical stimulation of vibration on proliferation of cells has been studied in vitro. To apply the vibration on the cells, a piezoelectric element was attached on the outside surface of the bottom of the culture plate of six wells. The piezoelectric element was vibrated by sinusoidal alternating voltage at 1.0 MHz generated by a function generator. Three kinds of cells were use...

This paper presents a new approach to vibration reduction of >exible spacecraft during attitude control by using pulse width pulse frequency (PWPF) modulator for thruster Cring and smart materials for active vibration suppression. The experiment was conducted on the Naval Postgraduate School (NPS)’s >exible spacecraft simulator (FSS), which consists of a central rigid body and an L-shape >exibl...

In this article, the design of rectangular symmetric bimorph piezoelectric ceramic transducers with loose and fixed edges and with parallel electric excitation is studied. Rectangular piezoelectric ceramic transducers in cosinusoidal flexural vibration with straight and parallel nodal lines of vibration are studied. The radiation of the transducer in a plane perpendicular to the surface of the ...

This paper presents a new approach to vibration reduction of flexible spacecraft during attitude control by using Pulse Width Pulse Frequency (PWPF) Modulator for thruster firing and smart materials for active vibration suppression. The experiment was conducted on the Naval Postgraduate School (NPS) 's Flexible Spacecraft Simulator (FSS) , which consists of a central rigid body and an L-shape f...

The main objective of this study is to reduce optimal vibration suppression of Timoshenko beam under non-periodic step and impulse inputs. Cantilever beam was modeled by Timoshenko theory and finite element numerical method. Stiffness (K), mass (M), and damping (C) matrices are extracted. Then, in order to control structure vibration, piezoelectric patches were used due to simultaneous dual beh...

In the present paper, electrical energy harvesting from random vibrations of an Euler-Bernoulli nano-beam with two piezoelectric layers is investigated. The beam is composed of an aluminum layer together with two piezoelectric ceramic layers (PZT 5A) serving as energy harvesting sensors. In the proposed method, the equations governing the bimorph nano-beam will be analytically derived using cla...

Coupled vibration of a radially polarized piezoelectric cylindrical transducer is analyzed with the mechanical coupling coefficient method. The method has been utilized to analyze the metal cylindrical transducer and the axially polarized piezoelectric cylindrical transducer. In this method, the mechanical coupling coefficient is introduced and defined as the stress ratio in different direction...

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...

This paper reports a novel actuating design that uses the shear deformation of a piezoelectric actuator to deflect a bulge-diaphragm for driving an array microdroplet ejector. In essence, we employed a circular-shaped actuator poled radial direction with remnant polarization normal to the actuating electric field for inducing the piezoelectric shear effect. The array microdroplet ejector consis...