Capacitance-based frequency adjustment of micro piezoelectric vibration generator.

Xinhua Mao,Hong Li,Qing He,Dongliang Chu

doi:10.1155/2014/484381

Xinhua Mao, Hong Li + Show 2 more

Open Access

https://doi.org/10.1155/2014/484381

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Abstract

Micro piezoelectric vibration generator has a wide application in the field of microelectronics. Its natural frequency is unchanged after being manufactured. However, resonance cannot occur when the natural frequencies of a piezoelectric generator and the source of vibration frequency are not consistent. Output voltage of the piezoelectric generator will sharply decline. It cannot normally supply power for electronic devices. In order to make the natural frequency of the generator approach the frequency of vibration source, the capacitance FM technology is adopted in this paper. Different capacitance FM schemes are designed by different locations of the adjustment layer. The corresponding capacitance FM models have been established. Characteristic and effect of the capacitance FM have been simulated by the FM model. Experimental results show that the natural frequency of the generator could vary from 46.5 Hz to 42.4 Hz when the bypass capacitance value increases from 0 nF to 30 nF. The natural frequency of a piezoelectric vibration generator could be continuously adjusted by this method.

Highlights

With the development of monitoring technology, wireless sensor networks are widely applied in medical monitoring, structural health monitoring, and industrial equipment condition monitoring and other fields
By various position relations among the adjusting layer, the piezoelectric layer, and the substrate, FM schemes of a piezoelectric generator have the following four cases based on capacitance FM technique
When bypass capacitance is less than 20 nF, the natural frequency could continuously change by adjusting the bypass capacitance

Summary

Introduction

With the development of monitoring technology, wireless sensor networks are widely applied in medical monitoring, structural health monitoring, and industrial equipment condition monitoring and other fields. At present, it has many problems in supplying power for wireless sensor network nodes. The purpose is to adjust its natural frequency It would increase the piezoelectric generator volume and production difficulty and raise the cost of production by this method. The piezoelectric generator has a lot of natural frequencies but brings out new manufacturing difficulties

Capacitance FM Principle and Theory Model of a Micro Piezoelectric Generator

Simulation and Analysis Based on FM Technology

Experiments and Result Analysis

1.10 Cantilever of scheme D

Conclusions