KR20160103347A - Micro Valve device and the fabricating method thereof - Google Patents

Abstract

The present invention relates to a microvalve element and a method of manufacturing the same. A microvalve element of the present invention comprises a fluid channel layer formed with a fluid channel and a fluid chamber, a valve diaphragm laminated on the fluid channel layer, and a valve chamber layer stacked on the valve diaphragm and having a pneumatic channel and a valve chamber formed And in particular, the fluid channel and the fluid chamber are formed semicircularly on the bottom surface. Therefore, when the compressed air flows from the outside, one side of the valve diaphragm contacts with the bottom surface of the fluid channel in accordance with the expansion of the valve chamber, so that the fluid flowing through the fluid channel can be completely blocked There is an advantage.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a micro valve device,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microvalve element, and more particularly, to a pneumatic microvalve having a channel and a chamber formed in a semicircular shape so as to completely prevent leakage of fluid, and a method of manufacturing the same.

Generally, an apparatus that performs biological or chemical reactions by manipulating a small volume of fluid is called a microfluidic device. The microfluidic device includes a microfluidic structure disposed in a platform of various shapes such as a chip, a disk, and the microfluidic structure includes a chamber in which a fluid can be confined, a channel through which the fluid can flow, and a microchip Valve, and can be made by various combinations thereof.

Here, the microvalve is a device (device) for supplying a precise amount of fluid by interrupting the flow of the fluid, which requires high reliability and extremely small size. In other words, a microvalve is an essential component for controlling fluid flow in a fluid platform, and can be classified into magnetic, electric, piezoelectric, and pneumatic. In particular, pneumatic microvalves are manufactured on the basis of microfluidics and soft-lithography.

The pneumatic microvalve can be divided into an open type and a closed type. Among them, an open type microvalve is used more easily than the closed type microvalve because of easy manufacturing and downsizing due to integration. An open pneumatic microvalve comprises a valve chamber, a deformable membrane, and a fluid channel. Wherein the membrane must completely seal the fluid chamber or fluid channel using a pressure change in the valve chamber.

However, currently used microvalves have a drawback in that they can not completely block fluid flow. This is because the shapes of the fluid chamber and the fluid channel are formed in a rectangular-cross-section.

The structure of the microvalve according to the present invention will now be described with reference to the problem that the fluid can not be completely blocked according to the chamber and channel structure of the conventional microvalve.

Korean Patent Laid-Open Publication No. 10-2011-0136629 (December 21, 2011: microfluidic device having a microvalve)

SUMMARY OF THE INVENTION An object of the present invention is to provide a microvalve element and a method of manufacturing the microvalve element, which can change the shape of a fluid chamber and a fluidic channel of a microvalve so as to precisely control fluid flow.

According to an aspect of the present invention, there is provided a fluid channel layer in which a fluid channel and a fluid chamber are formed; A valve diaphragm stacked on the fluid channel layer; And a valve chamber layer laminated on the valve diaphragm and having a pneumatic channel and a valve chamber formed therein.

The fluid channel layer, the valve diaphragm and the microvalve element are made of polydimethylsiloxane (PDMS).

The fluid channel and the fluid chamber are formed semicircularly on the bottom surface.

The diameter of the valve channel is made larger than the diameter of the fluid channel.

The diameter of the fluid channel and the diameter of the valve channel are 650 μm and 900 μm, respectively, and the width of the fluid channel and the pneumatic channel is 250 μm.

The fluid channel and the pneumatic channel are formed perpendicular to each other.

When compressed air is introduced through the pneumatic channel, one side of the valve diaphragm contacts the bottom surface of the fluid channel in accordance with the expansion of the valve chamber to block the fluid channel.

According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, the method comprising: placing a molded product on a silicon wafer and pouring polydimethylsiloxane (PDMS) to a predetermined thickness; Bonding a PDMS having grooves spaced apart from the molded product to a glass substrate; Providing PDMS with liquid phase PDMS and thermally curing the PDMS; Obtaining a PDMS having a semi-circular fluid chamber according to the thermal curing as a fluid channel layer; And combining the valve diaphragm and the valve chamber layer over the fluid channel layer.

And forming a semicircular fluid channel in the fluid chamber.

The fluid chamber and the fluid channel have heights of 150 mu m and 40 mu m, respectively.

The thermosetting process is carried out at 100 DEG C for about 30 minutes.

The micro valve element and the manufacturing method thereof according to the present invention have the following effects.

The present invention provides a microvalve element composed of three layers of a rapeseed channel layer, a valve diaphragm and a valve chamber layer, wherein a cross section of a fluid chamber and a fluid channel formed in the fluid channel layer is formed in a semicircular shape.

Therefore, when the external compressed air is introduced, the valve diaphragm is brought into contact with the bottom surface of the semicircular fluid chamber in accordance with the expansion of the valve chamber, so that the fluid flowing through the fluid channel can be blocked without leakage.

As a result, the microvalve element of the present invention can precisely control fluid flow.

1 is a perspective view of a microvalve according to a preferred embodiment of the present invention;
Fig. 2 is an exploded perspective view of Fig.
3 is a diagram illustrating an operation example of a conventional microvalve element and a microvalve element of the present invention
FIG. 4 is a flow chart illustrating a manufacturing process of a microvalve according to the present invention
5A is a SEM photograph showing a fluid chamber and a fluid channel of a microvalve element manufactured by the method of FIG.
FIG. 5B is a partial enlarged view of FIG.
6 is a view showing a leakage state of a conventional microvalve element and a microvalve element of the present invention
FIG. 7 is a graph showing the flow rate distribution state of the conventional microvalve element and the microvalve element of the present invention over time
8 is a graph comparing the efficiency characteristics of the conventional microvalve element and the microvalve element of the present invention
Figure 9 is a graph showing the vertical displacement of the valve diaphragm under various pressures;

The present invention forms a semicircular cross section of a fluid chamber and a fluid channel of a microvalve, so that a valve diaphragm which is expanded by compressed air supplied from the outside completely blocks the fluid channel and interrupts the fluid flow. do.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of a microvalve element and a manufacturing method thereof according to the present invention will be described in detail with reference to the accompanying drawings.

In describing the present invention, a microvalve, a micropneumatic valve, a pneumatic microvalve, and an open pneumatic microvalve all refer to the same valve, hereinafter referred to as a microvalve.

Also, the present invention proposes a microvalve in which a part of the structure of a conventional microvalve is improved in order to block leakage of fluid, and the performance of the two is analyzed through comparison of various experiments. Therefore, in the following description, a conventional microvalve and a microvalve according to the present invention will be described. It is noted that the microvalve is referred to as a microvalve according to the present invention when it is referred to as a microvalve without being referred to as a conventional microvalve.

FIG. 1 is a perspective view of a microvalve according to a preferred embodiment of the present invention, and FIG. 2 is an exploded perspective view of FIG.

Referring to FIGS. 1 and 2, the microvalve element 100 is composed of three polydimethylsiloxane (PDMS) layers. That is, the microvalve element 100 includes a fluid channel layer 110, a valve diaphragm layer 120, and a valve chamber layer 130 stacked from the bottom.

The fluid channel layer 110 is formed with a fluid channel 112 serving as a passage for the fluid and a fluid chamber 114 is formed in the middle of the path of the fluid channel 112. And the bottom surface of the fluid channel 112 and the fluid chamber 114 are both semicircular when viewed in cross section. In this embodiment, the diameter of the fluid chamber 114 is 650 mu m and the width of the rapier channel 112 is 250 mu m.

The valve chamber layer 130 is formed with a valve chamber 134 and a pneumatic channel 132 connected to one side of the valve chamber 134. The pneumatic channel 132 is a channel for supplying compressed air from the outside, and is formed in a direction perpendicular to the fluid channel 112. In this embodiment, the diameter of the valve chamber 134 is 900 mu m and the width of the pneumatic channel 132 is 250 mu m.

A valve diaphragm 120 (also referred to as a 'PDMS diaphragm') interposed between the fluid channel layer 110 and the valve chamber layer 130 is expanded in the direction of the fluid chamber 114 by a pressure change, And closes the connected fluid channel 112. That is, when the microvalve element 100 is externally supplied with compressed air through the pneumatic channel 132 to the valve chamber 134, the valve diaphragm 120 formed of a thin film is moved downward (i.e., in the direction of the bottom of the fluid chamber To close the fluid channel 112 while expanding. Thereby completely blocking the fluid flowing through the fluid channel 112 and the leakage of the fluid to the outside.

This can be seen from FIG. 3 showing an operation example of a conventional microvalve element and a microvalve element of the present invention. 3 (a) and 3 (b) show a conventional microvalve having a rectangular fluid chamber when viewed in section. Therefore, the valve diaphragm also expands in the downward direction due to the expansion of the valve chamber. In this case, it can be seen that the edge region A of the oil channel can not be blocked due to structural problems. 3 (c) and (d), the expansion of the valve chamber 134 causes the valve diaphragm 120 to expand in conformity with the semicircular shape of the fluid chamber 114. Thus, the valve diaphragm 120 is in perfect contact with the bottom surface of the fluid chamber 114, and thus can provide the effect that both fluid channels 112 associated with both sides of the fluid chamber 114 are blocked.

4 is a flow chart for explaining a manufacturing process of a microvalve according to the present invention.

(a), a polymethylsiloxane (PDMS) 3 is poured on a flat silicon wafer 1 in a state in which a molded product for forming a fluid chamber, that is, the SU-8 mold 2 is placed thereon and cured. In the embodiment, the thickness of the PDMS 3 is about 43 탆.

In this state, when the cured PDMS layer 3 is peeled off from the SU-8 2 as shown in FIG. 2B, the PDMS layer 3 having the grooves 4 from which the SU-8 2 is removed is obtained , And this is bonded to a glass substrate (5). Then, a liquid PDMS (6) is provided on the PDMS layer (3) as shown in Fig. At this time, the liquid phase PDMS 6 will be supplied in a series of structures (not shown) placed on the PDMS layer 3.

Thereafter, the liquid phase PDMS 6 is cured using a series of hot plate devices. The thermal curing process was carried out at 100 ° C for about 30 minutes. When the thermosetting process is performed, as shown in (d), the PDMS layer 3 is inflated as indicated by the arrow in accordance with the thermal expansion of the trapped air existing in the space of the groove 4, . And the deformed shape of the deformed PDMS layer 3 'is transferred directly to the PDMS 6 in the liquid phase, so that the deformed PDMS 6' is formed.

After the thermosetting process is completed, the glass substrate 5 and the PDMS layer 3 'are removed to obtain a PDMS layer 7 having a semicircular fluid chamber as shown in (e). And further forming a fluid channel is further performed. The fluid channel also has a semi-circular bottom surface. In this embodiment, the height of the semi-circular fluid chamber and the fluid channel is made to be 150 mu m and 40 mu m, respectively.

2, a valve diaphragm layer 120 and a valve chamber layer 130 described in FIG. 2 are coupled to the PDMS layer, that is, the fluid channel layer 110 (see FIG. 2) do.

Thereby, the microvalve element 100 can be manufactured.

FIG. 5A is a SEM photograph showing a fluid chamber and a fluid channel of a microvalve element manufactured by the method of FIG. 4, and FIG. 5B is a partial enlarged view of FIG. 5A. 5A, the height of the fluid chamber 114 is 150 μm, and the height of the fluid channel 112 is 40 μm, as described above. 5b, a wrinkle pattern is formed in the PDMS pattern. The wrinkle pattern is generated due to the compressive stress acting on the PDMS during the liquid-phase PDMS shrinkage due to the thermosetting process.

Hereinafter, differences between the conventional microvalve element and the microvalve element of the present invention will be described in more detail with reference to comparative explanations.

6 (a) and 6 (b) are conventional microvalve elements, and FIGS. 6 (c) and 6 (d) are views showing the state of the microvalve according to the present invention Showing a microvalve element.

In the conventional microvalve, fluid leakage occurs in the fluid channel, but the fluid is completely blocked in the microvalve of the present invention. 6, compressed air was supplied at a pressure of 100 kPa from the outside, and the fluid leakage state was observed through a digital microscope (Hi-Rox, KH-7700) and a flow sensor (Sensirion, ASL 1600) Respectively.

As described above, it can be seen that the fluid channel is completely closed by the valve diaphragm 120 in the microvalve device 100 of the present invention.

7 is a graph showing a flow rate distribution with respect to time, wherein (a) is a conventional microvalve element and (b) is a microvalve element of the present invention.

It can be seen that the microvalve element of the present invention significantly reduces the flow rate to about 400 seconds while shortening the on / off time of the valve compared to the conventional microvalve element.

8 is a graph showing the efficiency characteristics of the microvalve elements.

The valve efficiency is calculated based on the flow rate difference (Q Q). As shown in the graph, the flow rate was varied from 200 to 500 μl per minute.

In the graph, the valve efficiency of the present invention was larger than the conventional valve efficiency when the introduced flow rate was 200 mu l / min. That is, when the external pressure is 40 kPa, the microvalve element of the present invention is 97% and the conventional microvalve element is 65%. Also, the present invention is saturated when the valve efficiency increases rapidly and the pressure increases. On the other hand, the efficiency of the conventional valve gradually increased and became saturated. That is, the conventional microvalve element has difficulty achieving 100% efficiency within the applied pressure range. As the flow rate increases, the valve efficiency of the present invention is lower than that of conventional valves at lower pressures, but it can be seen that the valve efficiency of the present invention becomes much larger as the pressure increases.

Figure 9 is a graph showing the vertical displacement of the valve diaphragm under various pressures.

The displacement of conventional valves is limited by the depth of the fluid channel and chamber area. Therefore, the conventional valve diaphragm deforms even when a pressure of 20 kPa is applied, and contacts the center of the fluid chamber. And as the pressure increases, the contact area expands but fails to completely close the fluid chamber area.

However, as the pressure of the valve of the present invention increases, the valve diaphragm is fully expanded. The modified valve diaphragm covers both the interface of the fluid channel and the top of the fluid channel. Therefore, the fluid channel can be blocked.

As described above, according to the present embodiment, the bottom surface of the fluid chamber is formed in a semicircular shape so that the fluid channel is blocked by the valve diaphragm expanding in the downward direction corresponding to the expansion operation of the valve chamber when the compressed air is supplied. to provide.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It will be apparent that modifications, variations and equivalents of other embodiments are possible. Therefore, the true scope of the present invention should be determined by the technical idea of the appended claims.

110: fluid channel layer 112: fluid channel
114: fluid chamber 120: valve diaphragm
130: valve chamber layer 132: pneumatic channel
134: valve chamber

Claims (11)

A fluid channel layer formed with a fluid channel and a fluid chamber;
A valve diaphragm stacked on the fluid channel layer; And
And a valve chamber layer overlying the valve diaphragm and having a pneumatic channel and a valve chamber formed therein. The method according to claim 1,
Wherein the fluid channel layer, the valve diaphragm and the microvalve element are made of polydimethylsiloxane (PDMS). The method according to claim 1,
Wherein the fluid channel and the fluid chamber are formed semicircularly on the bottom surface. The method according to claim 1,
Wherein a diameter of the valve channel is larger than a diameter of the fluid channel. 5. The method of claim 4,
The diameter of the fluid channel and the diameter of the valve channel are 650 μm and 900 μm, respectively,
Wherein the fluid channel and the pneumatic channel have a width of 250 mu m. 6. The method of claim 5,
Wherein the fluid channel and the pneumatic channel are formed perpendicular to each other. The method according to claim 1,
Wherein one side of the valve diaphragm contacts the bottom surface of the fluid channel to block the fluid channel when the compressed air flows through the pneumatic channel. Placing a molded product on a silicon wafer and pouring polydimethylsiloxane (PDMS) to a predetermined thickness to cure the product;
Bonding a PDMS having grooves spaced apart from the molded product to a glass substrate;
Providing PDMS with liquid phase PDMS and thermally curing the PDMS;
Obtaining a PDMS having a semi-circular fluid chamber according to the thermal curing as a fluid channel layer; And
And combining the valve diaphragm and the valve chamber layer over the fluid channel layer. 9. The method of claim 8,
Further comprising forming a semicircular fluid channel in the fluid chamber. ≪ RTI ID = 0.0 > 11. < / RTI > 10. The method of claim 9,
Wherein the fluid chamber and the fluid channel have heights of 150 占 퐉 and 40 占 퐉, respectively. 9. The method of claim 8,
Wherein the thermosetting process is performed at 100 DEG C for about 30 minutes.

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