KR100403970B1 - a micro pump to using magnetic fluid and it's method for receiving magnetic fluid in a micro pump - Google Patents

Abstract

The present invention relates to a micro pump using MEMS (Micro Electro Mechanical Systems) technology and also applicable to medical applications, and in particular, by applying a magnetic fluid as a pumping source in place of a valve, which is a mechanical element, a device manufacturing cost reduction effect. It is designed to overcome the limitations of materials in the application of micro and micromachines.

An object of the present invention is to use a magnetic fluid to transfer the fluid to a certain position by the power generated by the deformation force that the fluid is deformed by the application of a magnetic field.

The present invention for this purpose, the first substrate 10 having a plurality of magnetic field generating unit 12 for generating a magnetic field; A second substrate stacked on the first substrate 10 and having a plurality of receiving spaces 22 accommodating the magnetic fluid 1 reacting by the magnetic field at a position corresponding to each of the magnetic field generating units 12. 20; The plurality of injection holes 32 are stacked on the second substrate 20 and have a plurality of injection holes 32 for injecting the magnetic fluid 1 into the receiving spaces 22, and the respective injection holes 32 are avoided. A third substrate 30 having a plurality of magnetic fluid flow spaces 33 in communication with the receiving space 22; A plurality of thin films 40 covering each of the magnetic fluid flow spaces 33 and made of a soft material that deforms when the magnetic fluid 1 reacts and returns when it does not react; And a flow path forming panel 50 disposed on the third substrate 30 at an appropriate interval to form a flow path 60 through which the driven fluid 2 is transferred between the third substrate 30. It is characterized by.

In addition, a step of dropping a certain amount of the liquid magnetic fluid (1) in the receiving portion of the first substrate 10, and applying the magnetic fluid (1) thinly and uniformly on the first substrate (10) by the spin corning method; Freezing the uniformly applied magnetic fluid (1); Planarizing the frozen magnetic fluid (1) and cutting it to a desired thickness; And bonding the second substrate 20 to the first substrate 10 and then thawing the magnetic fluid 1.

Description

A micro pump using magnetic fluid and a method for receiving a magnetic fluid in the micro pump {a micro pump to using magnetic fluid and it's method for receiving magnetic fluid in a micro pump}

The present invention relates to a micro pump using the technology of MEMS (MEMS: Micro Electro Mechanical Systems), and also applicable to medical applications. In particular, a magnetic fluid is applied as a pumping source instead of a valve, which is a mechanical element, to reduce the manufacturing cost of the device. It is designed to overcome the limitations of materials in the application of effects and micromachines.

In general, MEMS (Micro Electro Mechanical Systems) is interpreted as a micro precision mechanical technology, and refers to a technology that is made by integrating electrical and mechanical parts into a microminiature. These MEMS are widely applied to information recording devices, medical and biotechnology devices, fluid devices, inertial navigation system devices, optical components and displays.

In particular, one of the fluid elements, a micro pump (micro pump) has been used in medical applications for bloodless treatment and micro drug delivery means (apparatus).

These micro pumps are classified into three types according to the driving method.

First, it is a micropump using volume change of piezoelectric material by voltage. This micropump has advantages of large driving force and simple structure, but has a problem of applying a high voltage.

In addition, since there must be a manufacturing process that does not belong to the standard method, such as the bonding process on the piezo film or piezo stack, there is a problem that the manufacturing cost is high.

Second, it is a micro pump using the electrostatic force. This micro-pump is a simple structure in which two electrodes face each other with a small distance.As the size is reduced, the electrostatic force, which is the force acting on the surface, becomes the dominant force compared to gravity, so it has the ability to generate micro displacement, so that the super precise position control is possible. It can be implemented, and has the advantages of precise control (quantitative discharge), high speed response, etc., but high voltage must be applied, and there is a problem that the fluid is damaged while the transfer fluid is activated by the electric field.

Third, it is a micro pump using the volume change in the phase change of the material. This micropump has advantages of being driven with a large driving force and low voltage, but there are problems such as high temperature generation and low speed response.

Fourth, the micro-pump can be unidirectionally transported by using a check valve, but has a common problem that the life of the micro pump is short and causes malfunction.

As such micro-pumps currently used have their advantages, but they also have their weaknesses, so there is an urgent need for technology development to overcome them.

The present invention has been made to solve the above-mentioned conventional problems, mechanical durability is increased by using a magnetic fluid that can transfer the fluid to a certain position by the power generated by the deformation force of the magnetic fluid mechanical valve It is an object of the present invention to provide a micropump using a magnetic fluid that does not use.

Another object of the present invention is to provide a method of accommodating a magnetic fluid with a micro thickness in a micropump.

1 is a block diagram of a micro pump using a magnetic fluid according to the present invention

2 is an operation state diagram of a micro pump using a magnetic fluid according to the present invention 1

Figure 3 is an operating state of the micro pump using a magnetic fluid according to the present invention 2

Figure 4 is a flow chart showing a method for receiving a small thickness magnetic fluid in the micro-pump using the magnetic fluid according to the present invention

Explanation of symbols for main parts of the drawings

1: magnetic fluid 2: passive fluid

3: control unit 10: first substrate

11: first silicon panel 12: magnetic field generating unit

12a: partial magnetic field generator 12b: remaining magnetic field generator

13: magnetic fluid receiving groove 14: fluid barrier

20: second substrate 21: second silicon panel

22: accommodating space 30: third substrate

31: third silicon panel 32: injection hole

33: flow space 40: thin film

50: flow path forming panel 60: flow path

The present invention for achieving the above object, the first substrate having a plurality of magnetic field generating unit for generating a magnetic field; A second substrate stacked on the first substrate and having an accommodating space in which magnetic fluid reacting by a magnetic field is received at a position corresponding to each of the magnetic field generating units; A third substrate stacked on the second substrate and having an injection hole for injecting magnetic fluid into each of the receiving spaces and having a magnetic fluid flow space communicating with each of the receiving spaces to avoid the injection holes; A plurality of thin films covering each of the magnetic fluid flow spaces, the flexible material being deformed when the magnetic fluid reacts and returned when the magnetic fluid is unreacted; And a flow passage forming panel disposed on the third substrate at an appropriate interval to form a flow passage through which the driven fluid is transferred between the third substrate and the third substrate.

In addition, when the magnetic field is generated in some of the magnetic field generating units by the control unit, the magnetic field is not generated in the remaining magnetic field generating units. On the contrary, when the magnetic field is not generated in the partial magnetic field generating units, the remaining magnetic field generating units are generated. In the magnetic field is characterized in that the controlled to be repeated periodically.

In addition, a magnetic fluid receiving groove is formed in the upper portion of the first substrate, the magnetic fluid receiving groove is formed on the magnetic fluid receiving groove to form a projection-like fluid barrier, to prevent the magnetic fluid from agglomeration, the magnetic fluid is constant It is characterized by having a pressure.

In addition, a step of dropping a certain amount of the liquid magnetic fluid in the receiving portion of the first substrate, and applying the magnetic fluid thin and uniformly on the first substrate by the spin corning method; Freezing the uniformly applied magnetic fluid; Planarizing the frozen magnetic fluid and cutting it to a desired thickness; And bonding the second substrate onto the first substrate to thaw the magnetic fluid.

In addition, the freezing temperature of the magnetic fluid (1) is characterized in that -10 ℃.

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

First, since the present invention uses a magnetic fluid, it will be briefly described as to what is a magnetic fluid and its characteristics.

Magnetic fluid or ferrofluid is a colloidal solution in which ferromagnetic particles are uniformly dispersed in a medium (water or oil) .The colloid adsorbs a surfactant to ferromagnetic ultrafine particles to prevent aggregation and sedimentation in the liquid phase. It is manufactured by dispersing. It is completely stable and does not settle or aggregate even by gravity or magnetic gradient, and has macroscopic properties similar to single-phase fluid.

Therefore, in contrast to piezoelectric material whose volume is changed by applied voltage, or electroheological or magnetorheological fluid whose viscosity is changed by magnetic field or electric field, magnetic fluid is deformed by the applied magnetic field. Has the characteristic of becoming.

Such magnetic fluids have been proposed and tried in all fields such as specific gravity screening, magnetic seals, speaker cooling materials, magnetic recording materials, waste oil treatment, and various devices.

The configuration of the micropump using the magnetic fluid will be described with reference to FIG. 1. 1 is a block diagram of a micro pump using a magnetic fluid according to the present invention.

According to the drawing, the micropump of the present invention has a configuration in which the first substrate 10, the second substrate 20, and the third substrate 30 are sequentially stacked and coupled. The apparatus further includes a thin film 40 of the soft material stacked on the third substrate 30, and a flow path forming panel 50 disposed on the third substrate 30 at an appropriate interval.

As shown in FIG. 1, the first substrate 10 is completed by a multi-step operation such as etching (etching), patterning, and deposition on the first silicon panel 11 and the first silicon panel 11. It consists of a magnetic field generating unit 12.

In this case, the magnetic field generating unit 12 is formed on the first substrate 10 with a plurality of intervals.

In addition, the plurality of magnetic field generating units 12 are connected to the control unit 3, and the magnetic field is generated only in some of the magnetic field generating units by the control of the control unit 3, except for the other magnetic field generating units, the magnetic field is generated. On the contrary, if a magnetic field is not generated in some magnetic field generating units, the magnetic field is generated in the remaining magnetic field generating units so that the magnetic field is continuously repeated at regular intervals.

The selective magnetic field generation for the magnetic field generating unit 12 is a cause that enables the transfer of the driven fluid 2. Detailed description thereof will be described later.

In addition, a magnetic fluid receiving groove 13 in which the magnetic fluid 1 is accommodated is formed on the first substrate 10, and a fluid barrier 14 having a protrusion shape is formed on the magnetic fluid receiving groove 13. Thus, the magnetic fluid 1 accommodated in the magnetic fluid receiving groove 13 is prevented from agglomeration, and the magnetic fluid 1 can be maintained at a constant pressure.

In addition, the second substrate 20 is formed by forming an accommodation space 22 having upper and lower openings at a position corresponding to each of the magnetic field generators 12 in the second silicon panel 21. At this time, each receiving space 22 is a space in which the magnetic fluid (1) is accommodated.

In addition, the third substrate 30 has an injection hole 32 for injecting the magnetic fluid 1 into each of the accommodation spaces 22 on the third silicon panel 31.

In addition, the plurality of magnetic fluid flow spaces 33 communicating with the accommodation spaces 22 are formed in the places where the injection holes 32 are avoided. At this time, each of the magnetic fluid flow space 33 is a space in which the magnetic fluid 1 is reacted by the magnetic field.

In addition, a plurality of thin films 40 of the soft material covering each of the magnetic fluid flow spaces 33 are provided on the third substrate 30 so as to deform when the magnetic fluid 1 reacts and to return when the magnetic fluid 1 does not react. .

In addition, a flow path forming panel 50 is disposed on the third substrate 30 at appropriate intervals, and the flow path 60 through which the driven fluid 2 is transferred between the third substrate 30 and the flow path forming panel 50. Was formed.

The transfer of the driven fluid 2 in the flow path 60 is made by whether the magnetic field is generated in the magnetic field generating unit 12 and the magnetic fluid 1 that reacts or is not reacted thereby.

On the other hand, Figure 4 is a flow chart showing a method for accommodating a magnetic fluid to a micropump with a small thickness.

According to the drawing, the magnetic fluid receiving method according to the present invention in one step, drop the magnetic fluid 1 of the liquid on the first substrate 10 by a predetermined amount, and is applied thinly and uniformly by the spin coating method.

In the second step, the liquid magnetic fluid 1 applied on the first substrate 10 is frozen at a predetermined temperature. At this time, the freezing temperature is possible below 0 ° C, but it is preferable to freeze at a temperature below 10 ° C to obtain a certain hardness.

In step 3, the frozen magnetic fluid is flattened and processed to a desired thickness using a cutting tool such as a blade.

In the fourth step, after bonding the second substrate 20 on the first substrate 10, the magnetic fluid 1 can be thawed to accommodate the microfluidic magnetic fluid in the micropump.

The operation of the micropump using the magnetic fluid having the above configuration will be described later.

2 required for this description is an operation state of the micropump using the magnetic fluid according to the present invention, and FIG. 3 is an operation state of the micropump using the magnetic fluid according to the present invention.

First, when power is applied to some of the magnetic field generating units 12a of the plurality of magnetic field generating units 12 by the control of the control unit 3 as shown in FIG. 2, the magnetic field generating unit 12a to which the power is applied is applied. This will occur.

Accordingly, the magnetic fluid 1 accommodated in the receiving space 22 placed at a position corresponding to the portion of the magnetic field generating unit 12a where the magnetic field is generated is reacted by the magnetic field, and the magnetic fluid flows through the third substrate 30. Force to be discharged through the space 33 is generated.

At this time, the thin film 40 covering the magnetic fluid flow space 33 is convexly upwardly deformed by the pressure ΔP to discharge the magnetic fluid 1.

The pressure ΔP generated by the magnetic fluid 1 is proportional to the product of the magnetization value of the magnetic fluid 1 and the applied magnetic field strength. Formulating this, ΔP = μM · ΔH, M is the magnetization value, and ΔH represents the intensity of the applied magnetic field.

Therefore, the driven fluid 2 located in the flow path 60 can secure fluidity that can be moved to a predetermined position by generating a pressure difference due to the deformation of the magnetic fluid 1.

Subsequently, power is cut off to some of the magnetic field generators 12a in which the magnetic field is generated by the control of the control unit 3 as shown in FIG. 3, and power is supplied to the remaining magnetic field generators 12b in which the magnetic field is not generated. As a result, the thin film 40 of the remaining magnetic field generator 12b protrudes by the magnetic fluid 1, and the partial magnetic field generator 12 is returned.

Therefore, the driven fluid 2 located in the flow path 60 is transferred by the interval of the protruding thin film 40b, and thus, the partial magnetic field generating unit 12a and the remaining magnetic field generating unit 12b are alternately projected repeatedly. By returning, the driven fluid 2 located in the flow path 60 can be transported to a predetermined position.

In this case, when the frequency of the electric signal used to control the magnetic field is adjusted by the natural frequency of the flexible thin film, the thin film forms a traveling wave, which enables effective fluid transfer.

The present invention as described above has a number of advantages that the magnetic fluid can be applied to the micropump by using a characteristic that the shape is deformed by the magnetic field, and thus, a large driving force can be obtained, and a quick response and a low voltage can be driven.

Claims (5)

In a micro pump comprising a magnetic field generating unit for generating a magnetic field and a magnetic fluid in response to the magnetic field, A first substrate 10 having a plurality of magnetic field generators 12 generating a magnetic field in a central portion of an upper surface thereof; A second substrate 20 stacked on the first substrate 10 and having a receiving space 22 in which a magnetic fluid 1 reacting by a magnetic field is received at a position corresponding to each of the magnetic field generators 12. ); The plurality of injection holes 32 are stacked on the second substrate 20 and have a plurality of injection holes 32 for injecting the magnetic fluid 1 into the receiving spaces 22, and the respective injection holes 32 are avoided. A third substrate 30 having a magnetic fluid flow space 33 in communication with the accommodation space 22; A plurality of thin films 40 covering each of the magnetic fluid flow spaces 33 and made of a soft material that deforms when the magnetic fluid 1 reacts and returns when it does not react; A flow channel forming panel 50 disposed on the third substrate 30 at an appropriate interval to form a flow path 60 through which the driven fluid 2 is transferred between the third substrate 30; When the magnetic field is generated in the magnetic field generating unit 12a by the control unit 3, the plurality of magnetic field generating units 12 do not generate magnetic fields in the other magnetic field generating unit 12b, and vice versa. When the magnetic field is not generated at 12a, the remaining magnetic field generating unit 12b periodically repeats the operation of generating the magnetic field; A magnetic fluid accommodating groove 13 in which the magnetic fluid 1 is accommodated is formed on the first substrate 10, and a fluid barrier 14 having a protrusion shape is formed on the magnetic fluid accommodating groove 13. A micro-pump using a magnetic fluid, characterized in that the magnetic fluid (1) is prevented from agglomerating and the magnetic fluid (1) has a constant pressure. delete delete Dropping a certain amount of the liquid magnetic fluid (1) on the receiving portion of the first substrate (10), and applying the magnetic fluid (1) thinly and uniformly on the first substrate (10) by spin coating; Freezing the uniformly applied magnetic fluid (1); Planarizing the frozen magnetic fluid (1) and cutting it to a desired thickness; A method of receiving a magnetic fluid in a micro-pump using a magnetic fluid, characterized in that it comprises a step of thawing a magnetic fluid (1) after bonding the second substrate (20) on the first substrate (10). The method of claim 4, wherein The freezing temperature of the magnetic fluid (1) is a method for receiving a magnetic fluid in a micro-pump using a magnetic fluid, characterized in that -10 ℃.