CN103746604A - Photonic crystal power generating device based on lateral vibration band gap - Google Patents

Abstract

The invention provides a phononic crystal power generation device based on a transverse vibration bandgap. It includes a main beam and a support beam. A piezoelectric material and a mass block are connected to the support beam to form a local oscillator unit. Multiple local oscillator units with the same structure are symmetrically and equidistantly installed on the main beam to form a phononic crystal structure. The invention uses piezoelectric technology to convert energy, and adopts phonon crystal technology to realize broadband and high-efficiency power generation of a power generation device in a vibrating environment. The overall structure is simple, the manufacture is convenient, and the transverse vibration power generation frequency band of the piezoelectric vibration device is effectively widened, no active control is required, and the requirements for the working environment are relatively low. It can be used for energy supply of microelectronic products such as wireless sensors, etc.

Description

A Phononic Crystal Power Generation Device Based on Transverse Bandgap

technical field

The present invention relates to a power generating device, in particular to a piezoelectric vibration power generating device suitable for generating power by utilizing the lateral vibration band gap of a phononic crystal in a vibration and noise environment.

Background technique

In recent years, with the development of integrated circuit technology and micro/nano electromechanical system technology, microelectronic products are widely used in wireless network nodes, environmental monitoring, automobiles, buildings and other important fields. At present, the development of microelectronic products is limited by the miniaturization and lifespan of energy supply devices, so it is very important to develop new micro power supply technology. At present, most of the chemical power supply schemes used in micro-electromechanical systems are only suitable for short life cycles, and it is difficult to cope with the increasing number of wireless network nodes. The vibration power generation device based on the piezoelectric effect can only generate small-scale power, but It has been able to meet the requirements of the micro-power consumption system, and the vibration source used by it is ubiquitous, has the advantages of not being limited by the site, and has strong mobility. Therefore, the use of piezoelectric vibration power generation devices can solve the problem of self-supply of MEMS.

The current cantilever beam power generation structure that has been studied more is facing the problem of "single resonance frequency and low power generation efficiency". In order to improve power generation efficiency and broaden the frequency band of power generation, there are currently two commonly used methods: 1. Active self-adjustment method, that is, to adapt to the change of environmental vibration frequency by actively controlling the natural frequency of the adjustment device; 2. Passive self-adjustment method, namely The effect of widening the frequency band is achieved through the combination of multiple power generating devices with different natural frequencies. Both methods have disadvantages, the former consumes a lot of energy itself, and the latter significantly increases the size and design cost of the device. In the "Frequency Analysis and Power Generation Experimental Research of Multi-cantilever Piezoelectric Vibrator" published in Volume 44, Issue 2, February 2010 of "Journal of Xi'an Jiaotong University", a multi-cantilever piezoelectric vibrator structure is proposed, which belongs to In the category of passive self-adjustment, several different cantilever vibrators are connected in series on the same substrate, thereby widening the power generation frequency band of the power generation device to 56-65Hz and increasing the power generation capacity. However, in this structure, different cantilever beams are arranged on the same substrate, and the design of the cantilever beam is complicated and the production cost is high.

Contents of the invention

The object of the present invention is to provide a phononic crystal power generation device based on a transverse vibration bandgap that can widen the bandwidth of the power generation frequency band, improve power generation efficiency, and have low manufacturing cost.

The purpose of the present invention is achieved like this:

Including the main beam and the support beam, the piezoelectric material and the quality block are connected to the support beam to form a local vibrator unit. Multiple local vibrator units with the same structure are installed symmetrically and equidistantly on the main beam to form a phonon crystal structure. The surface of the piezoelectric material on the vibrator unit is parallel to the axis of the main beam.

The present invention may also include:

1. The main beam is a square or round beam made of silicon, metal or elastic material.

2. The local vibrator unit includes a support beam, a piezoelectric material bonded to one side of the support beam, and a mass block bonded to one side of the end of the support beam.

3. The local vibrator unit includes a support beam, a piezoelectric material bonded to both sides of the support beam, and a mass block bonded to one side of the end of the support beam.

4. The local vibrator unit includes a support beam, a piezoelectric material bonded to both sides of the support beam, and a mass block bonded to both sides of the end of the support beam.

The invention is mainly designed for the power supply of microelectronic products, uses piezoelectric technology to convert energy, and adopts phonon crystal technology to realize broadband and high-efficiency power generation of a power generation device in a vibrating environment. The principle is to symmetrically arrange several groups of power generation beams (local oscillators) at equal intervals along the length direction of the main beam to form a local resonance type phonon crystal structure. Due to the dynamic vibration absorption of the local oscillators and the coupling effect between them, different The central frequency and the lateral vibration band gaps of different bandwidths make the power generation beam vibrate violently within this frequency range, converting mechanical energy into electrical energy, and finally realizing the broadband power generation effect of lateral vibration.

In the present invention, several identical cantilever beam oscillators are symmetrically installed on the elastic main beam at equal intervals to form a local resonance type phonon crystal structure. Larger vibrations are generated inside, thereby converting mechanical energy into electrical energy, thereby effectively widening the bandwidth of the power generation frequency band of the device and improving the power generation efficiency of the device. The local resonance phononic crystal has a low transverse bandgap frequency, and the position and width of the bandgap can be changed by adjusting the size of the cantilever beam oscillator and the spacing between the oscillators. It is suitable for power generation in low frequency vibration environment. In terms of the mechanism of widening the power generation frequency band, the present invention is fundamentally different from the serial scheme of the background art, and also has the advantages of large power generation and low design and manufacturing costs.

In a word, the present invention has the advantages of simple overall structure, convenient manufacture, effectively widening the transverse vibration power generation frequency band of the piezoelectric vibration device, no need for active control, and low requirements for the working environment. It can be used for energy supply of microelectronic products such as wireless sensors, etc.

Description of drawings

Fig. 1 is a three-dimensional structural schematic diagram of an embodiment of a phononic crystal power generation device based on a transverse vibration bandgap of the present invention.

Fig. 2 is a schematic structural diagram of a local vibrator with a single mass block of a bimorph.

Fig. 3 is a three-dimensional structural schematic diagram of another embodiment of the phononic crystal power generation device based on the transverse vibration bandgap of the present invention.

Fig. 4 is a schematic diagram of the structure of a local vibrator with a single mass block of a unimorph.

Fig. 5 is a schematic diagram of the structure of the local vibrator of the dual-mass mass of the bimorph.

Detailed ways

The present invention will be described in more detail below with examples in conjunction with the accompanying drawings.

Referring to FIG. 1 , the technical solution of the present invention mainly includes a main beam 1 , a piezoelectric material 2 , a quality block 3 and a support beam 4 .

The main beam 1 is used to connect with the machine base in the vibration environment or directly as the machine base, and the material is silicon, metal or elastic material, etc.; the material of the piezoelectric material 2 is piezoelectric ceramics or piezoelectric film; the material of the mass block 3 is copper , nickel and other metals; the material of the beam 4 is silicon. The piezoelectric material 2 and the mass block 3 are bonded to the support beam 4 by bonding and other reasonable processes to form a local vibrator. The local vibrator is installed on the main beam 1 symmetrically and equidistantly as a unit by welding, embedded connection, etc. , so as to form a phononic crystal structure, the surface of the piezoelectric material on each local vibrator is parallel to the axis of the main beam to generate a lateral vibration band gap. The structural size of the power generation support beam and the main beam, and the number of periods of the power generation structure can be adjusted according to the needs of the use environment. After the device converts mechanical vibration into electrical energy, it is processed by a rectifier for storage or energy supply.

In actual use, the following factors should be taken into consideration to improve the above-mentioned embodiment.

⑴. Main beam and local oscillator structure. According to the vibration frequency and intensity of the working environment and the energy demand of the equipment used, the structure of the main beam or local oscillator can be changed, as shown in Figures 3, 4, and 5. When the required power is large, the single piezoelectric sheet can be changed to a double piezoelectric sheet, the number of mass blocks can also be changed, and the main beam can also be replaced by a circular section main beam instead of a square section main beam.

⑵.Materials of main beam and local vibrator. According to the vibration frequency of the working environment, the composition materials of the main beam and the local vibrator are changed, so as to adjust the band gap frequency to match the vibration frequency of the external environment.

⑶. The number of cycles of the structure. The number of periods of the phononic crystal can be adjusted according to the requirements of the geometric size, the amount of power generation, and the range of the frequency band.

Claims (5)

1. the phonon crystal Blast Furnace Top Gas Recovery Turbine Unit (TRT) based on the horizontal band gap of shaking, comprise girder and strutbeam, on strutbeam, connect piezoelectric and mass and form local oscillator unit, it is characterized in that: the identical local oscillator unit of a plurality of structures is symmetrical and be arranged on equally spacedly on girder and form phonon crystal structure, the surface of the piezoelectric on each local oscillator unit is parallel to the axis of girder.

2. the phonon crystal Blast Furnace Top Gas Recovery Turbine Unit (TRT) based on the horizontal band gap of shaking according to claim 1, is characterized in that: the square or circular beam of described girder for being made by silicon, metal or elastomeric material.

3. the phonon crystal Blast Furnace Top Gas Recovery Turbine Unit (TRT) based on the horizontal band gap of shaking according to claim 1 and 2, is characterized in that: described local oscillator unit comprises strutbeam, is bonded in the piezoelectric of strutbeam one side, is bonded in the mass of beam end one side.

4. the phonon crystal Blast Furnace Top Gas Recovery Turbine Unit (TRT) based on the horizontal band gap of shaking according to claim 1 and 2, is characterized in that: described local oscillator unit comprises strutbeam, is bonded in the piezoelectric of strutbeam both sides, is bonded in the mass of beam end one side.

5. the phonon crystal Blast Furnace Top Gas Recovery Turbine Unit (TRT) based on the horizontal band gap of shaking according to claim 1 and 2, is characterized in that: described local oscillator unit comprises strutbeam, is bonded in the piezoelectric of strutbeam both sides, is bonded in the mass of a beam end both sides.

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