KR20150137731A - Piezoelectric pump for microfluid devices - Google Patents

Abstract

The present invention relates to a piezoelectric pump comprising: an elastic chamber part which has a fluid inlet where fluid is put and a fluid outlet to discharge the fluid; and a piezoelectric body part which is arranged on the outer surface of the elastic chamber part, wherein the elastic chamber part is formed in either a rectangular parallelepiped shape or in a cylindrical shape. The present invention enables easy manufacture by simplifying the structure thereof as a check valve for preventing a backflow is not required and improves the durability and reliability of the pump.

Description

PIEZOELECTRIC PUMP FOR MICROFLUID DEVICES

The present invention relates to a piezoelectric pump, and more particularly, to a piezoelectric pump having a simple structure without using a check valve.

Recent advances in MEMS technology for medical and polymer chemistry have led to increased research and demand for microfluidic transport systems. The micropump, which is a key element of the microfluidic transport system, controls the supply of the gasified fuel and the analysis and delivery of the sample together with a fixed amount of microfluid depending on the purpose of use.

However, existing motor-driven pumps have limitations in performance and size due to limitations in size and power consumption.

Therefore, there is an increasing tendency to use piezo-electric pumps, which do not greatly change characteristics in the surrounding environment, can be miniaturized on a micro scale, have quick reactivity, and have low power consumption.

The piezoelectric driving method applied to these fields uses an inverse piezoelectric effect which generates a mechanical displacement when an electric field is applied to the piezoelectric element, and there are unimorph, bimorph, and laminated type according to the combination of the elastic body and the piezoelectric body.

The first micropump based on the operation of pump membranes and valves began in the mid-1970s.

Since then, micropumps have attracted much attention, and the development of microfluidics and microfluidics has become an important goal.

Over the past decade, a number of different theoretical models and principles of micropump have been proposed. One of them is a piezoelectric pump that utilizes a piezoelectric effect that generates electrical polarization when it applies mechanical stress to the material or creates mechanical strain when an electric field is applied to the material.

Conventionally, a piezoelectric pump includes a main body, an inlet and an outlet, a controller, a check valve, and a driver.

The main body forms an outer shape of the piezoelectric pump, and a space for receiving a fluid is formed inside. The inlet port and the outlet port may be connected to the main body to allow the fluid to flow into and out of the internal space.

The check valves are respectively provided at the inlet and the outlet to prevent backflow of the fluid. That is, the fluid flows only in the direction of the main body at the inlet port side, and the fluid flows only in the direction from the main body at the outlet port side.

The driving unit is composed of a diaphragm and a piezoelectric element provided on the back surface thereof. The driving unit is a component that is controlled by the controller and performs a pumping action. The driving unit generates a pressure difference in the interior space of the main body while vibrating in a vertical direction, Let it flow.

That is, a generally used check valve type piezoelectric pump cuts backflow phenomenon of a fluid by using an active valve.

This is because the pressure between the chamber and the chamber varies depending on the operation of the actuator and is repeatedly opened and closed. However, due to fatigue and wear caused by fluid flow, repetitive operation, etc., .

Korean Patent Publication No. 10-2010-42361

An object of the present invention is to provide a piezoelectric pump having a simple structure without using a check valve.

The objects of the present invention are not limited to the above-mentioned objects, and other objects not mentioned can be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided a fluid ejecting apparatus including: an elastic chamber part including a fluid inlet through which fluid flows and a fluid outlet through which fluid is discharged; And a piezoelectric part disposed on an outer surface of the elastic chamber part, wherein the elastic chamber part has a rectangular parallelepiped shape or a cylindrical shape.

The present invention further provides a piezoelectric pump, wherein the elastic chamber portion further comprises a channel formed continuously with the fluid inlet and the fluid outlet.

In the present invention, when the elastic chamber portion is in the form of a rectangular parallelepiped, the piezoelectric body portion includes a first piezoelectric body portion disposed on a first surface of the elastic chamber portion, a second piezoelectric body portion disposed on a second surface, 3 piezoelectric body portion and a fourth piezoelectric body portion disposed on the fourth surface.

Further, in the present invention, when the elastic chamber portion is in a cylindrical shape, the piezoelectric portion is a ring shape disposed along the outer surface of the elastic chamber portion in a cylindrical shape.

According to another aspect of the present invention, there is provided a refrigerator including a first opening and closing part for opening and closing the fluid inlet, and a second opening and closing part for opening and closing the fluid outlet, wherein the first opening and closing part includes: And the second opening and closing part includes a second shutter part that is opened and closed in accordance with a change in shape of the second fixing part and the second fixing part.

According to the present invention as described above, since the check valve for preventing the backflow is not used, the construction is simplified to facilitate manufacture, and the durability and reliability of the pump can be improved.

In addition, according to the present invention, since the self-locking function is provided when the power is shut off, a separate shut-off valve is not required, so that the structure is simple and the durability and reliability of the pump can be improved.

Further, according to the present invention, since the space inside the main body is not required, miniaturization is possible.

In addition, according to the present invention, it is possible to switch the pumping direction of the fluid easily by replacing the voltage application, so that it can be used in both directions.

Fig. 1 shows progressive wave generation in a piezoelectric body in which two piezoelectric plates are spaced apart.
FIG. 2A is a conceptual view showing the principle of a piezoelectric motor, and FIG. 2B is a conceptual view showing a fluid transportation principle by a peristaltic motion of a piezoelectric pump.
FIG. 3A is a schematic cross-sectional view illustrating a piezoelectric pump according to a first embodiment of the present invention, and FIG. 3B is a schematic perspective view illustrating a piezoelectric pump according to a first embodiment of the present invention.
FIGS. 3C and 3D are schematic diagrams for explaining the process of synthesizing the standing waves to become progressive waves. FIG.
FIG. 4 shows a linkage analysis procedure using a finite element analysis program, Comsol Multiphysics.
5 is a diagram showing a shape of an analysis model according to each drive.
6 is a view showing the movement of the elastic body by the traveling wave.
FIG. 7 is a view showing a flow direction of the fluid according to FIG. 6. FIG.
FIG. 8 is a graph showing flow characteristics according to three shapes and chamber height changes after fixing the bottom surfaces of the respective piezoelectric bodies.
FIG. 9 is a graph showing flow characteristics according to three shapes and chamber height changes after the bottom surfaces of the piezoelectric bodies are not fixed.
10 is a graph showing the flow characteristics of back pressure and chamber height change according to three shapes.
11 is a schematic perspective view showing a piezoelectric pump according to a second embodiment of the present invention.
12A is a schematic cross-sectional view showing a piezoelectric pump according to a third embodiment of the present invention, and FIG. 12B is a schematic view showing an opening and closing part of a piezoelectric pump according to a third embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and the manner of achieving them, will be apparent from and elucidated with reference to the embodiments described hereinafter in conjunction with the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. &Quot; and / or "include each and every combination of one or more of the mentioned items. ≪ RTI ID = 0.0 >

Although the first, second, etc. are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used only to distinguish one component from another. Therefore, it goes without saying that the first component mentioned below may be the second component within the technical scope of the present invention.

The terminology used herein is for the purpose of illustrating embodiments and is not intended to be limiting of the present invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. The terms " comprises "and / or" comprising "used in the specification do not exclude the presence or addition of one or more other elements in addition to the stated element.

Unless defined otherwise, all terms (including technical and scientific terms) used herein may be used in a sense commonly understood by one of ordinary skill in the art to which this invention belongs. Also, commonly used predefined terms are not ideally or excessively interpreted unless explicitly defined otherwise.

The terms spatially relative, "below", "beneath", "lower", "above", "upper" And can be used to easily describe a correlation between an element and other elements. Spatially relative terms should be understood in terms of the directions shown in the drawings, including the different directions of components at the time of use or operation. For example, when inverting an element shown in the figures, an element described as "below" or "beneath" of another element may be placed "above" another element . Thus, the exemplary term "below" can include both downward and upward directions. The components can also be oriented in different directions, so that spatially relative terms can be interpreted according to orientation.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Fig. 1 shows progressive wave generation in a piezoelectric body in which two piezoelectric plates are spaced apart.

1, the two piezoelectric plates 11 and 12, which are respectively driven by AC signals of the same frequency, are divided into one of the segments (polarization) / 2 < / RTI >

The two piezoelectric plates having the above arrangement are arranged at intervals of a quarter wavelength of the standing wave. Since the two segments are full-wave lengths, when one of the piezoelectric plates 11 is applied with a sine wave while the other plate 12 is driven with a cosine wave, the offsets of the half- Causing a standing wave of one element in which the wavelength of a quarter of the phase is deformed.

This results in a quarter wavelength that deviates from the phase simultaneously.

As a result of these signals, a combination of two standing waves produces a traveling wave at a spaced 1/4 wavelength apart at the spaced apart intervals, and at the same frequency off 1/4 wavelength from the phase due to the difference between sine and cosine waves. The above-mentioned generation of the traveling wave provides the basic operation of the piezoelectric motor for driving the piezoelectric pump.

Hereinafter, the basic structure of the piezoelectric motor and the piezoelectric pump using the traveling wave will be described.

FIG. 2A is a conceptual view showing the principle of a piezoelectric motor, and FIG. 2B is a conceptual view showing a fluid transportation principle by a peristaltic motion of a piezoelectric pump.

First, referring to FIG. 2A, the operation of the piezoelectric motor will be described. Since the traveling wave travels through the elastic plate (stator) 26, all points on the surface of the rotor 25 move to an elliptical path.

Since the rotor is reliably depressing the stator, the elliptical motion transmits torque to the rotor 25 and propels it in the direction opposite to the traveling wave, as shown. The operation of the piezoelectric motor depends on the friction of the interface between the rotor 25 and the stator 26. The operation of such a motor provides a basis for the operation of a piezoelectric pump capable of transferring liquid or gas.

Next, referring to FIG. 2B, the principle of the piezoelectric pump applying the piezoelectric motor will be described. In the sine wave curve space 30 of the traveling wave, the floor portions of the vibration traveling waves generated on the surfaces of the elastic bodies are in contact with each other, It can be seen that several spaces are formed (32) apart.

The spaces 32 thus provide a basis for the delivery of liquid or gas in the direction of traveling waves in the peristaltic motion. The piezoelectric pump is physically composed of two stators (elastic diaphragm) 31 having faces facing each other without a rotor. Therefore, the moving space 32 of the piezoelectric pump doubles. The traveling wave 30 is generated at the interface at the same time and forms a plurality of continuous spaces 32 to sufficiently fill the liquid or gas.

Therefore, the interlocking action is not substantially related to the moving part, and the fluid or gas follows the traveling wave direction. The main feature of these piezoelectric pumps is that they do not require check valves to prevent backflow or valves to prevent overall flow. The reason is that the interlocking of the piezoelectric pump creates a tightly closed space that can play an important role as a squeeze effect. When the voltage of the piezoelectric pump is turned off, the boundary surfaces between the two elastic bodies (stator) are in close contact with each other without displacement, and the flow of the fluid is stopped. Thus, the self-locking phenomenon occurs as if the conventional valve is completely stopped.

Hereinafter, a piezoelectric pump according to the present invention to which the principle of traveling wave as described above is applied will be described.

FIG. 3A is a schematic cross-sectional view illustrating a piezoelectric pump according to a first embodiment of the present invention, and FIG. 3B is a schematic perspective view illustrating a piezoelectric pump according to a first embodiment of the present invention.

3A and 3B, a piezoelectric pump 100 according to the first embodiment of the present invention includes an elastic chamber part (not shown) including a fluid inlet 131 through which fluid flows and a fluid outlet 132 through which fluid is discharged 110, and piezoelectric parts 121, 122 disposed on the outer surface of the elastic chamber part 110.

At this time, the elastic chamber part 110 includes a channel 131 formed continuously with the fluid inlet 131 and the fluid outlet 132.

In the first embodiment of the present invention, the resilient chamber portion 110 may have a rectangular parallelepiped shape.

3A and 3B, the piezoelectric body portion includes first piezoelectric bodies 121a and 122a disposed on the first surface of the elastic chamber portion 110 having a rectangular parallelepiped shape, second piezoelectric bodies 121a and 122a disposed on the second surface, The first and second piezoelectric bodies 121b and 122b and the third piezoelectric bodies 121c and 122c disposed on the third surface and the fourth piezoelectric bodies 121d and 122d disposed on the fourth surface.

At this time, although the figure shows that each of the first to fourth piezoelectric bodies is arranged on each of the four surfaces, the number of the piezoelectric bodies arranged on each of these surfaces is not limited in the present invention.

On the other hand, the two piezoelectric parts of the respective piezoelectric parts, for example, the first piezoelectric parts 121a and 122a disposed on each surface can form a single piezoelectric body, and a sine wave and a cosine wave .

In this case, the first piezoelectric bodies 121a and 122a act as a stator of the piezoelectric motor to generate the above-mentioned traveling wave.

The traveling wave generates a peristaltic motion in the elastic chamber part 110, and a space generated by the peristaltic motion causes a pumping action.

The effects of the piezoelectric pump according to the present invention will be described as follows.

First, according to the present invention, a check valve for preventing backflow is not used, so that the construction is simplified, and the durability and reliability of the pump can be improved.

Second, the present invention has a self-locking function when the power is shut off, so that a separate shut-off valve is not required, which simplifies the structure and improves durability and reliability of the pump.

Third, according to the present invention, since the space inside the main body is not required, miniaturization is possible.

Fourthly, according to the present invention, it is possible to easily change the pumping direction of the fluid by replacing the voltage application, so that it can be used in both directions.

Hereinafter, the operation principle of the piezoelectric pump according to the present invention will be described.

The piezoelectric pump according to the present invention is a method of applying a sinusoidal wave and a cosine wave to a piezoelectric body to synthesize two standing waves having a temporal and spatial phase difference of 90 degrees to generate a traveling wave to move the fluid.

That is, as shown in FIG. 3A, the curved surface of the elastic chamber portion is vertically symmetrical, and the chamber is shrunk and expanded due to the traveling wave of 180 degrees phase difference generated therein, thereby moving the fluid.

The operation of the piezoelectric pump according to the present invention can be arranged according to a conditional expression on the four piezoelectric parts having a phase difference of spatially by a wavelength of 4 according to the traveling wave excitation method of piezoelectric and the equation about the condition thereof.

Then, when an alternating voltage having a phase difference of a period / 4 is applied, a traveling wave which is a composite wave of two standing waves is produced. When traveling waves symmetrical 180 degrees to the curved surface generated by the traveling wave are opposed to each other, the micro chamber existing between the interfaces proceeds and can be applied to fluid transportation.

The following is a mathematical representation of the process by which standing waves are synthesized.

FIGS. 3C and 3D are schematic diagrams for explaining the process of synthesizing the standing waves to become progressive waves. FIG.

The bending vibration wave of each piezoelectric ceramic of PZT can be expressed by the following equations (1) and (2).

수학식 (1)

Equation (1)

수학식 (2)

Equation (2)

Here, if a phase difference angle made a later by a is expressed by the following equation (3)

수학식 (3)

Equation (3)

The above equation (2) can be summarized by the following equation (4).

수학식 (4)

Equation (4)

The composite expression of the expressions (1) and (4) can be expressed by the following expression (5).

수학식 (5)

Equation (5)

As a final result, A = B, so that the following equation (6) is obtained.

수학식 (6)

Equation (6)

In order to generate this traveling wave, the arrangement of the ceramic and the polarity should be set.

As shown in FIG. 3C, the number of the used piezoelectric elements, the length of the wavelength, the length of the piezoelectric element, the distance between the piezoelectric element and the piezoelectric element are set, and are generated by driving excitation of sin and cos, do.

In Fig. 3, the excitation of the (-) sign is realized by reversing the polarity of the bonded piezoelectric ceramics.

This type requires two oscillating sources to excite two standing waves, so the efficiency is not as high as 50% or less, but it has the advantage of easily changing the phase difference and the direction of fluid entry and exit.

The piezoelectric pump according to the present invention is designed in the form of a smooth traveling wave and a peristaltic motion of the stomach.

Also, as a multiphysical model, a strain of a piezoelectric body and an elastic body is transmitted to a fluid. When an AC voltage is applied to a piezoelectric body, tensile and shrinkage deformation are repeatedly generated along the polarization direction.

Therefore, when the traveling wave generated from the flexure surface of the elastic body changes the volume of the chamber with time, a deflection flow due to the change of the position and velocity of the fluid is formed.

That is, the amplitude of the AC voltage affects the strain of the piezoelectric, and the deformation of the elastic body accordingly affects the change in the flow rate in the chamber, resulting in a correlation between the volume of the chamber and the rate of change of the flow rate.

FIG. 4 shows a linkage analysis procedure using a finite element analysis program, Comsol Multiphysics.

Referring to FIG. 4, first, the piezoelectric displacement amount generated in the piezoelectric body is coupled to the elastic body and the fluid. This is to allow different velocity changes to the displacement of the structure to interact with the velocity of the fluid in the tube, where each module receives and transmits the momentum at the interface between the fluid and the structure.

Also, during the dynamic analysis over time and repeatedly calculating until the solution converges at every time interval, the physical solution in the piezoelectric body is derived, transferred to the elastic body and the fluid, and finally the flow rate of the fluid is calculated.

The interface between the fluid and the structure was set to no-slip, and the fluid was moved only by the speed due to the traveling wave generated in the piezoelectric body.

Table 1 shows the physical properties of the piezoelectric element PZT-4 used in the analysis. SBR (Styrene Butadiene Rubber) was used for the fluid and water.

In this analytical model, the chambers located at both ends of the pump can reproduce similar conditions with the experimental model and confirm the flow while stabilizing the fluid at both inlet and outlet.

FIG. 5 is a view showing a shape of an analytical model according to each driving, FIG. 6 is a view showing a movement of an elastic body by a traveling wave, and FIG. 7 is a view showing a flow direction of the fluid according to FIG.

Table 2 shows the size of the piezoelectric micropump according to the traveling wave excitation condition equation.

The frequency of the power source applied to the piezoelectric body is 160 Hz, the driving voltage is sin and cos, and the standing waves are applied at 100 V, respectively. In the case of the chamber inlet / outlet (fluid inlet and fluid outlet of the elastic chamber) Is assumed to be the initial pressure.

In addition, the design parameters are divided into fixed and unfixed piezoelectric substrates, and the experimental conditions for applying 2-phase (c ₄ ), 3-phase (c ₃ ), and 2-phase group driving (c _g ) Flow characteristics and pressure characteristics.

FIG. 8 is a graph showing flow characteristics according to three shapes and chamber height changes after fixing the bottom surfaces of the respective piezoelectric bodies.

In the case of the two phases, the average displacement was 8.32, the chamber height was 0.1 to 227, the average displacement in the three phases was 8.96, and the chamber size was 0.1 to 267. The average displacement of the two-phase group was 3.4 and the chamber size was 0.1 to 148.

For the maximum flow rate, 0.1 of the 3-phase group exhibited the best flow characteristics, and for the continuous flow, the 2-phase flow characteristics were relatively good.

FIG. 9 is a graph showing flow characteristics according to three shapes and chamber height changes after the bottom surfaces of the piezoelectric bodies are not fixed.

The average displacement for the two phases was 8.03, the chamber size was 0.1 to the maximum 139, the average displacement for the three phases was 5.1, and the chamber size ranged from 0.1 to 77.4. For the two-phase group, the average displacement was 3.97, and the chamber size was from 1 to 4.26.

For the maximum flow rate, the best flow characteristics were obtained at 0.1 of 2-phase drive, and the 3-phase flow characteristics at constant flow rate were relatively good.

10 is a graph showing the flow characteristics of back pressure and chamber height change according to three shapes.

In the case of 2 phase, 0.1 to 6.13 Pa. In the case of 3 phase, the chamber showed a flow rate of 0.1 mm to 7.75 Pa. In the case of 2-phase group, the maximum pressure was 0.1mm to 8.5 Pa.

The present invention proposes a method for controlling the delivery of microfluidic and gaseous substances in a microfluidic pump, which is a key element of a microfluidic transport system applied to medical and polymer chemistry fields. In addition, The applicability was verified.

Simulation results show that the flow rate when the bottom of the piezoelectric body is fixed is higher than the condition that the entire piezoelectric body is not fixed. This is because the amount of displacement of the interface between the fluid and the elastic body is increased by maximizing the displacement of the piezoelectric body. Also, the average displacements in the two - phase and three - phase systems were similar in the upper fixed system, but the difference in flow rate was due to the difference in back pressure.

As for the driving method, it is shown that the four-phase, which has excellent characteristics of the three-phase and the maximum flow, which are excellent in the average flow rate, can be used in different phases according to the application field.

11 is a schematic perspective view showing a piezoelectric pump according to a second embodiment of the present invention. The piezoelectric pump according to the second embodiment of the present invention can be the same as the above-described first embodiment except for the following.

11, the piezoelectric pump 200 according to the second embodiment of the present invention includes an elastic chamber part 210 including a fluid inlet 231 through which a fluid flows and a fluid outlet 232 through which fluid is discharged, And piezoelectric portions 221 and 222 disposed on the outer surface of the elastic chamber 210. [

At this time, the elastic chamber 210 includes a channel 231 formed continuously with the fluid inlet 231 and the fluid outlet 232.

In the second embodiment of the present invention, the resilient chamber portion 210 may have a cylindrical shape.

11, the piezoelectric unit may be in the shape of a ring arranged along the outer surface of the elastic chamber part 210 having a cylindrical shape.

In other words, in the first embodiment of the present invention, the piezoelectric body is divided into four sides of the rectangular parallelepiped elastic chamber portion. However, in the second embodiment of the present invention, the piezoelectric body is continuously arranged along the outer surface of the elastic- They can be arranged in a ring shape.

At this time, although four piezoelectric bodies are shown in the drawing, the number of piezoelectric bodies is not limited in the present invention.

On the other hand, two piezoelectric parts of each of the disposed piezoelectric parts can form one piezoelectric body, and a sinusoidal wave and a cosine wave can be respectively applied in a power supply part (not shown).

In this case, the piezoelectric bodies 221 and 122 serve as stator of the piezoelectric motor to generate the above-mentioned traveling wave.

The traveling wave generates a peristaltic motion in the elastic chamber part 210, and a space generated by the peristaltic motion causes a pumping action.

12A is a schematic cross-sectional view showing a piezoelectric pump according to a third embodiment of the present invention, and FIG. 12B is a schematic view showing an opening and closing part of a piezoelectric pump according to a third embodiment of the present invention. The piezoelectric pump according to the third embodiment of the present invention can be the same as the first embodiment or the second embodiment described above except for the following.

12A, a piezoelectric pump 300 according to a third embodiment of the present invention includes an elastic chamber 310 including a fluid inlet 331 through which fluid flows and a fluid outlet 332 through which fluid is discharged And piezoelectric parts 321 and 322 disposed on the outer surface of the elastic chamber part 310. [

The elastic chamber 310 includes a channel 331 formed continuously with the fluid inlet 331 and the fluid outlet 332.

In the third embodiment of the present invention, the resilient chamber portion 310 may have a rectangular parallelepiped shape and may be cylindrical as in the above-described FIG.

12A, the piezoelectric body portion includes first piezoelectric bodies 321a and 322a disposed on the first surface of the elastic chamber 310 having a rectangular parallelepiped shape, second piezoelectric bodies 321a and 322b disposed on the second surface, (Not shown), third piezoelectric portions 321c and 322c disposed on the third surface, and a fourth piezoelectric portion (not shown) disposed on the fourth surface. Since this is the same as the first embodiment, a detailed description will be omitted below.

As described above, the elastic chamber part according to the third embodiment of the present invention may be in the form of a cylinder. In this case, the piezoelectric part may be a ring-shaped part disposed along the outer surface of the elastic chamber part 310, . Since this is the same as the second embodiment, a detailed description will be omitted below.

12A, the piezoelectric pump according to the third embodiment of the present invention includes a first opening and closing part 340 for opening and closing the fluid inlet 331 and a second opening and closing part for opening and closing the fluid outlet 332 350).

That is, it is possible to control the inflow of the fluid into the fluid inlet port 331 according to the opening and closing of the first opening and closing part 340, and to control the flow of the fluid to the fluid outlet port 332 It is possible to control the discharge of the fluid.

12B is a schematic view showing an opening / closing part of the piezoelectric pump according to the third embodiment of the present invention, and shows the first opening and closing part as an example.

Referring to FIG. 12B, the first opening and closing part may include a fixing part 341 and a shutter part 342 which is opened and closed according to a change in shape of the fixing part 341.

That is, the fixing portion 341 is fixed to one end of the elastic chamber portion 410, and the shape of the fixing portion 341 is also deformed by the deformation of the elastic chamber portion 410.

By deforming the fixing portion 342, the shape of the shutter portion 342 is deformed, and the fluid inlet 331 can be opened and closed as shown in FIG. 12B.

12B shows only the first opening and closing part, but the second opening and closing part is also the same. With this structure, the fluid outlet 332 can be opened and closed.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

Claims (5)

An elastic chamber portion including a fluid inlet through which the fluid flows and a fluid outlet through which the fluid is discharged; And
And a piezoelectric body portion disposed on an outer surface of the elastic chamber portion,
Wherein the elastic chamber portion has a rectangular parallelepiped shape or a cylindrical shape. The method according to claim 1,
Wherein the elastic chamber portion further comprises a channel formed continuously with the fluid inlet and the fluid outlet. The method according to claim 1,
When the elastic chamber portion has a rectangular parallelepiped shape, the piezoelectric portion includes a first piezoelectric portion disposed on a first surface of the elastic chamber portion, a second piezoelectric portion disposed on a second surface, a third piezoelectric portion disposed on a third surface, And a fourth piezoelectric part arranged on four sides. The method according to claim 1,
Wherein when the elastic chamber portion has a cylindrical shape, the piezoelectric body portion has a ring shape disposed along an outer surface of the elastic chamber portion having a cylindrical shape. The method according to claim 1,
A first opening and closing part for opening and closing the fluid inlet, and a second opening and closing part for opening and closing the fluid outlet,
Wherein the first opening and closing part includes a first fixing part and a first shutter part opened and closed in accordance with a change in shape of the first fixing part,
And the second opening and closing part includes a second shutter part that is opened and closed in accordance with a change in shape of the second fixing part and the second fixing part.

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