Numerical study of cantilevers with non-uniform width for enhancing the performance of vibration-driven micropower generator based on piezoelectric conversion

This study is dedicated to investigation of rectangular- and trapezoidal-shaped cantilevers for achieving improved efficiency of the piezoelectric micropower generation. The developed finite element model of a unimorph piezotransducer with a proof-mass at the tip is used to examine how different cantilever shapes and proof-mass dimensions influence stress distribution, dynamic response and voltage output of the microgenerator. Numerical results indicate that cantilevers with increasingly triangular shape permit markedly larger kinematic excitation magnitudes and generate slightly larger voltages for a comparable deflection level

Miniature rotary tables with piezoelectric hemispheres: research and development

The aim of this research is to develop and investigate two modifications of high resolution miniature rotary tables, based on the transformation of 3D resonant oscillations of hemisphere actuators into continuous or start-stop motion of contacting rotary table. To generate 3D resonant oscillations of the contacting points, the electrodes of the actuators are sectioned into several parts, enabling the generation of traveling wave type higher forms of oscillations. The results of modeling of hemisphere actuators are presented together with experimental investigation of resolution and response time. It is shown that axial oscillations of the table and its torsional oscillations can be generated, extending the functionality of the devices

Design and dynamic modeling of piezoelectric laser beam shutters

The paper presents the results of numerical modelling and experiments of piezoelectric bimorph-type bending actuator for laser beam shutting system. Theoretical calculations are realized by using finite element method. The purpose of these calculations is to optimize geometric parameters of a piezoelectric bimorph, ensuring maximum resonant frequency of the first bending form and stability of oscillation amplitude. Experimental performance of piezoelectric actuators is compared with results of finite element simulations

Development of two modifications of piezoelectric high resolution rotary table

The aim of this paper is to describe two modifications of high resolution rotary tables with angular position control, based on the transformation of resonant oscillations of piezoelectric transducers into continuous or start-stop motion. Exact angular position of the table is achieved by application of integrated classical rotary position encoders and feedback system, related to the given position or angular velocity of the device. Dimensions and cost of the table should be dramatically reduced, thus ensuring competitiveness in modern markets

Multiphysical modeling of a contact-type piezotransducer for the analysis of micro-energy harvesting from ambient vibrations

The paper presents development of a coupled-field finite element model of a contact-type piezoelectric transducer, which acts as a micropower source for MEMS sensors by harvesting energy from ambient vibrations. The proposed FE model of the cantilever-type piezotransducer couples three different physical domains: mechanical, piezoelectrical and fluidic. Both linear and nonlinear piezoelectric models are implemented. The fluid-structure interaction is modeled as viscous air damping, which manifests in the form of squeeze-film damping governed by the nonlinear compressible isothermal Reynolds equation. Vibro-impact interaction is modeled through implementation of a special adhesive-repulsive contact model that is suitable for contact simulations at the micro-scale. Performance of the FE model is demonstrated by representative dynamic simulations including parametric studies that reveal the influence of structural, excitation and ambient pressure parameters on dynamical and electrical performance of the device

R&D of high resolution rotary table based on the ultrasonic standing waves

This paper covers the essential information associated with recently developed piezoelectric rotary drive being able to act as the basis for most of forthcoming relevant devices. The aim of the work is to investigate such a novel table the operation of which relies on transformation of resonant ultrasonic standing wave oscillations into continuous or start-stop motion. Angular position of the device is registered by means of integrated optical encoder-type subsystem. A significant attention is paid to the structure, numerical analysis and dynamic characteristics of the drive

Numerical study of cantilevers with non-uniform width for enhancing the performance of vibration-driven micropower generator based on piezoelectric conversion

This study is dedicated to investigation of rectangular- and trapezoidal-shaped cantilevers for achieving improved efficiency of the piezoelectric micropower generation. The developed finite element model of a unimorph piezotransducer with a proof-mass at the tip is used to examine how different cantilever shapes and proof-mass dimensions influence stress distribution, dynamic response and voltage output of the microgenerator. Numerical results indicate that cantilevers with increasingly triangular shape permit markedly larger kinematic excitation magnitudes and generate slightly larger voltages for a comparable deflection level

Design and dynamic modeling of piezoelectric laser beam shutters

The paper presents the results of numerical modelling and experiments of piezoelectric bimorph-type bending actuator for laser beam shutting system. Theoretical calculations are realized by using finite element method. The purpose of these calculations is to optimize geometric parameters of a piezoelectric bimorph, ensuring maximum resonant frequency of the first bending form and stability of oscillation amplitude. Experimental performance of piezoelectric actuators is compared with results of finite element simulations