Bidirectional micropump based on double-layer nickel-titanium-based shape memory alloy film driving

Abstract

The invention discloses a two-way micropump driven by a double-layer nickel-titanium-based shape memory alloy film, and relates to the technical field of microfluid transmission and control and micromachinery. The invention aims to solve the problem that an existing micropump cannot realize alternate conveying and bidirectional conveying of two different liquids or the same liquid. The device comprises a left cover plate, a gasket, a right cover plate, a first shape memory alloy diaphragm, a pressing block, a second shape memory alloy diaphragm and four copper foil sheets, and the first shape memory alloy diaphragm and the second shape memory alloy diaphragm are oppositely arranged between the right cover plate and the left cover plate in parallel. The gasket is arranged on the outer edge between the first shape memory alloy diaphragm and the second shape memory alloy diaphragm, and the pressing block is arranged in the middle between the first shape memory alloy diaphragm and the second shape memory alloy diaphragm. The outer sides of the edges of the upper portions and the lower portions of the first shape memory alloy membrane and the second shape memory alloy membrane are each provided with a copper foil piece. The invention is used for liquid delivery of the micro-flow control system.

Description

Technical Field

[0001] The invention relates to the fields of microfluid transmission and control and micromechanical technology, and in particular to a bidirectional micropump driven by a double-layer nickel-titanium-based shape memory alloy film. Background Art

[0002] Microflow control system is a new technology field that has emerged in recent years. Developed countries abroad are conducting large-scale research in this field. Since the dead liquid volume fraction of microflow control system is low and it can accurately adjust or pump a small amount of fluid, its application will bring revolutionary changes to the fields of medicine, chemical analysis and fuel delivery. As the core component of microflow control system, micropump has become a hot research topic for scholars at home and abroad. In micropump, the stroke of the actuator determines the pumping volume of each cycle, and its force determines the ability to generate pressure. NiTi-based shape memory alloy film is an excellent candidate material for driving in this application because it can withstand both high force and large strain, which can be directly converted into high pressure and large stroke respectively. In addition to these characteristics, NiTi-based shape memory alloy film can be driven at high frequency because it has a large surface area to volume ratio. Although researchers at home and abroad have designed a variety of micropumps based on shape memory alloys in recent years, the micropumps so far cannot achieve alternating and bidirectional delivery of two different liquids or the same liquid, and cannot meet the needs of such micro-dispensing and delivery in the fields of biomedicine, chemical analysis and fuel delivery. Summary of the invention

[0003] In order to solve the problem that the existing micro pump cannot realize the alternate delivery and bidirectional delivery of two different liquids or the same liquid, the present invention further proposes a bidirectional micro pump driven by a double-layer nickel-titanium-based shape memory alloy film.

[0004] The technical solution adopted by the present invention to solve the above technical problems is:

[0005] A bidirectional micro pump driven by a double-layer nickel-titanium-based shape memory alloy film comprises a left cover plate, a gasket, a right cover plate, a first shape memory alloy diaphragm, a pressing block, a second shape memory alloy diaphragm and four copper foils. The right cover plate and the left cover plate are arranged opposite to each other, the first shape memory alloy diaphragm and the second shape memory alloy diaphragm are arranged oppositely and in parallel between the right cover plate and the left cover plate, the gasket is arranged at the outer edge between the first shape memory alloy diaphragm and the second shape memory alloy diaphragm, the pressing block is arranged in the middle between the first shape memory alloy diaphragm and the second shape memory alloy diaphragm, a copper foil is respectively arranged on the outer sides of the upper and lower edges of the first shape memory alloy diaphragm and the second shape memory alloy diaphragm, a locking assembly is arranged between the left cover plate and the right cover plate to press the left cover plate, the right cover plate, the first shape memory alloy diaphragm, the gasket, the second shape memory alloy diaphragm and the four copper foils, an outlet first check valve and an inlet first check valve are respectively arranged on the right cover plate, and an outlet second check valve and an inlet second check valve are arranged on the left cover plate.

[0006] Furthermore, sealing rings are provided between the outer edge of the first shape memory alloy diaphragm and the right cover plate and between the outer edge of the second shape memory alloy diaphragm and the left cover plate, and the sealing rings are arranged on the outside of the copper foil.

[0007] Furthermore, the sealing ring is made of insulating and heat-insulating elastic material.

[0008] Furthermore, the locking assembly includes a plurality of bolts and a plurality of nuts. The bolts are evenly distributed along the circumferential direction and pass through the edges of the end faces of the left cover plate and the right cover plate respectively. The ends of the bolts are threadedly connected with nuts for locking.

[0009] Furthermore, the thickness of the pressing block is greater than the thickness of the gasket.

[0010] Furthermore, the shape of the pressing block is cylindrical, and the end faces of the pressing block are in contact with the first shape memory alloy diaphragm and the second shape memory alloy diaphragm respectively.

[0011] Furthermore, the gasket and the pressing block are made of insulating and heat-insulating materials.

[0012] Furthermore, the first shape memory alloy diaphragm and the second shape memory alloy diaphragm are both made of a nickel-titanium-based shape memory alloy thin film material that is martensite at room temperature.

[0013] Furthermore, the outer side of the copper foil extends outwardly in the radial direction to the outside of the first shape memory alloy diaphragm and the second shape memory alloy diaphragm.

[0014] Furthermore, the left cover plate, the right cover plate, the first shape memory alloy diaphragm and the second shape memory alloy diaphragm are all circular in shape.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The present invention provides a micro pump capable of realizing alternating bidirectional delivery of two different liquids or the same liquid, which has the characteristics of simple structure, compactness, small volume, low cost, high efficiency and strong controllability.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] 1. One cycle of reciprocating motion of the pressure block can realize the delivery of liquid in two pump chambers, doubling the efficiency.

[0019] 2. The two pump chambers are independent of each other and can transport two different liquids respectively. Pump chambers of different sizes can be used to control the delivery volume of the two chambers.

[0020] 3. Two liquids or the same liquid can be transported from different channels without affecting each other.

[0021] 4. If necessary, the two output channels can be combined into one channel to experiment with the mixed delivery of two liquids or the large flow delivery of the same liquid.

[0022] 5. No external action mechanism is required, compact structure, small size and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0024] Figure 2 yes Figure 1 side view schematic diagram;

[0025] Figure 3 It is a schematic diagram of the overall structure of the micro pump of the present invention when it is in a working state;

[0026] Figure 4 It is a schematic diagram of the overall structure of the micro pump of the present invention in working state 2.

[0027] In the figure, 1-left cover plate; 2-sealing ring; 3-copper foil; 4-washer; 5-right cover plate; 6-nut; 7-bolt; 8-first outlet check valve; 14-second outlet check valve; 9-first shape memory alloy diaphragm; 10-pressure block; 11-first inlet check valve; 12-second inlet check valve; 13-second shape memory alloy diaphragm. DETAILED DESCRIPTION

[0028] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0029] Specific implementation method 1: Combination Figure 1 to Figure 2 The present embodiment is described. The bidirectional micro pump based on double-layer nickel-titanium-based shape memory alloy film drive described in the present embodiment comprises a left cover plate 1, a gasket 4, a right cover plate 5, a first shape memory alloy diaphragm 9, a pressing block 10, a second shape memory alloy diaphragm 13 and four copper foils 3. The right cover plate 5 and the left cover plate 1 are arranged opposite to each other. The first shape memory alloy diaphragm 9 and the second shape memory alloy diaphragm 13 are arranged opposite to each other in parallel between the right cover plate 5 and the left cover plate 1. The gasket 4 is arranged at the outer edge between the first shape memory alloy diaphragm 9 and the second shape memory alloy diaphragm 13. The pressing block 10 is arranged at the first In the middle part between the shape memory alloy diaphragm 9 and the second shape memory alloy diaphragm 13, a copper foil 3 is respectively provided on the outer sides of the upper and lower edges of the first shape memory alloy diaphragm 9 and the second shape memory alloy diaphragm 13, and a locking assembly is provided between the left cover plate 1 and the right cover plate 5 to press the left cover plate 1, the right cover plate 5, the first shape memory alloy diaphragm 9, the gasket 4, the second shape memory alloy diaphragm 13 and the four copper foils 3, and the right cover plate 5 is respectively provided with an outlet first check valve 8 and an inlet first check valve 11, and the left cover plate 1 is provided with an outlet second check valve 14 and an inlet second check valve 12.

[0030] In this embodiment, the left cover plate 1 and the right cover plate 5 are made of metal or non-metal material with sufficient strength. The first outlet check valve 8 and the first inlet check valve 11, the second outlet check valve 14 and the second inlet check valve 12 are all traditional passive check valves.

[0031] The outlet first check valve 8 is arranged at the upper part of the right cover plate 5, and the inlet first check valve 11 is arranged at the lower part of the right cover plate 5; the outlet second check valve 14 is arranged at the upper part of the left cover plate 1, and the inlet second check valve 12 is arranged at the lower part of the left cover plate 1. The outlet second check valve 14 is arranged opposite to the outlet first check valve 8, and the inlet second check valve 12 is arranged opposite to the inlet first check valve 11.

[0032] Specific implementation method 2: Combination Figure 1 to Figure 2 To illustrate this embodiment, in this embodiment, a sealing ring 2 is provided between the outer edge of the first shape memory alloy diaphragm 9 and the right cover plate 5 and between the outer edge of the second shape memory alloy diaphragm 13 and the left cover plate 1 . The sealing ring 2 is provided on the outside of the copper foil 3 .

[0033] The undisclosed technical features in this embodiment are the same as those in the first embodiment.

[0034] Specific implementation method three: Combination Figure 1 to Figure 2 To describe this embodiment, the sealing ring 2 in this embodiment is made of insulating and heat-insulating elastic material.

[0035] The undisclosed technical features in this embodiment are the same as those in the second embodiment.

[0036] In this embodiment, the sealing ring 2 is made of rubber or other insulating and heat-insulating materials with a certain elasticity.

[0037] Specific implementation method four: Combination Figure 1 to Figure 2 To illustrate this embodiment, the locking assembly described in this embodiment includes a plurality of bolts 7 and a plurality of nuts 6. The bolts 7 are evenly distributed along the circumferential direction and pass through the edges of the end faces of the left cover plate 1 and the right cover plate 5 respectively. The ends of the bolts 7 are threadedly connected with the nuts 6 for locking.

[0038] The undisclosed technical features in this embodiment are the same as those in the first embodiment.

[0039] The nut 6 and the bolt 7 are standard parts.

[0040] Specific implementation method five: Combination Figure 1 to Figure 2 To explain this embodiment, the thickness of the pressing block 10 in this embodiment is greater than the thickness of the gasket 4 .

[0041] The undisclosed technical features in this embodiment are the same as those in the first embodiment.

[0042] The thickness difference between the pressing block 10 and the gasket 4 should ensure that the maximum deformation of the shape memory alloy diaphragm does not exceed 8%.

[0043] Specific implementation method six: Combination Figure 1 to Figure 2 To explain this embodiment, the shape of the pressing block 10 in this embodiment is cylindrical, and the end faces of the pressing block 10 are in contact with the first shape memory alloy diaphragm 9 and the second shape memory alloy diaphragm 13 respectively.

[0044] The undisclosed technical features in this embodiment are the same as those in the third embodiment.

[0045] Specific implementation method seven: Combination Figure 1 to Figure 2 To explain this embodiment, the gasket 4 and the pressing block 10 described in this embodiment are made of insulating and heat-insulating materials.

[0046] The undisclosed technical features in this embodiment are the same as those in the first embodiment.

[0047] The gasket 4 and the pressing block 10 are both made of insulating and heat-insulating materials to prevent heat transfer between the two shape memory alloy diaphragms.

[0048] Specific implementation method eight: Combination Figure 1 to Figure 2 To explain this embodiment, in this embodiment, the first shape memory alloy diaphragm 9 and the second shape memory alloy diaphragm 13 are both made of a nickel-titanium-based shape memory alloy thin film material that is martensite at room temperature.

[0049] The undisclosed technical features in this embodiment are the same as those in the first embodiment.

[0050] Specific implementation method nine: Combination Figure 1 to Figure 2 To explain this embodiment, the outer side of the copper foil 3 in this embodiment extends outwardly in the radial direction to the outside of the first shape memory alloy diaphragm 9 and the second shape memory alloy diaphragm 13 .

[0051] The undisclosed technical features in this embodiment are the same as those in the first embodiment.

[0052] Specific implementation method ten: Combination Figure 1 to Figure 2 To explain this embodiment, the shapes of the left cover plate 1 , the right cover plate 5 , the first shape memory alloy diaphragm 9 and the second shape memory alloy diaphragm 13 in this embodiment are all circular.

[0053] The undisclosed technical features in this embodiment are the same as those in the first embodiment.

[0054] How it works

[0055] The first shape-memory alloy diaphragm 9 and the second shape-memory alloy diaphragm 13 are both flat before assembly. After assembly, since their peripheries are tightly pressed between the gasket 4 and the sealing ring 2, and the middle part is supported by the thicker pressing block 10, Figure 1 The four copper foils 3 are connected to a power supply connected to a thermal resistor, and the heat of the thermal resistor can be transferred to the first shape memory alloy diaphragm 9 and the second shape memory alloy diaphragm 13. When the first shape memory alloy diaphragm 9 is heated, the diaphragm will produce a shape memory effect due to the transformation of the martensite phase into the austenite phase, and return to the plane state before deformation. Since the detwinning deformation of martensite is easier to occur than the stress-induced martensite phase transformation of austenite, the pressing block 10 will move toward the unheated second shape memory alloy diaphragm 13 to cause it to deform more, as shown in FIG. Figure 3 Working state 1 is shown. When the heating of the first shape memory alloy diaphragm 9 is stopped, it transforms from austenite to martensite after cooling, and when the second shape memory alloy diaphragm 13 is heated, the diaphragm will also return to the plane state before deformation due to the shape memory effect, and the driving block 10 moves toward the first shape memory alloy diaphragm 9, forcing the first shape memory alloy diaphragm 9 to bend and deform. Figure 4 Working state 2 is shown. In this way, one thermal cycle will cause the pressure block 10 to drive the two diaphragms to swing back and forth once, so that the volumes of the pump chamber formed between the left cover plate 1 and the first shape memory alloy diaphragm 9 and the pump chamber formed between the right cover plate 5 and the second shape memory alloy diaphragm 13 will change alternately, realizing alternating bidirectional delivery of the pump.

[0056] The implementation method of the present invention includes the following process:

[0057] Before working, the state of the bidirectional micro pump is as follows: Figure 1 As shown in , at this time both the left and right pump chambers are filled with liquid.

[0058] When the power supply connected to the first shape memory alloy diaphragm 9 on the right side is turned on to heat it, the diaphragm returns to the flat state before assembly due to the shape memory effect, and the pressing block 10 moves to the left, causing the second shape memory alloy diaphragm 13 to bend and deform to the left, so that the volume of the right pump chamber reaches the maximum and the volume of the left pump chamber reaches the minimum. At this time, the external liquid is injected into the right pump chamber through the first inlet check valve 11, and the liquid in the left pump chamber flows out through the second outlet check valve 14. Figure 3 shown.

[0059] When the power supply of the first shape memory alloy diaphragm 9 on the right is disconnected and the heating is stopped, it will quickly cool to room temperature and transform into the martensite phase. At this time, the power supply of the second shape memory alloy diaphragm 13 on the left is connected to heat it. The diaphragm returns to the plane state before assembly due to the shape memory effect. The pressing block 10 moves to the right and causes the first shape memory alloy diaphragm 9 to bend to the right, so that the volume of the left pump chamber reaches the maximum and the volume of the right pump chamber reaches the minimum. At this time, the external liquid is injected into the left pump chamber through the inlet second check valve 12, and the liquid in the right pump chamber flows out through the outlet first check valve 8. Figure 4 shown.

[0060] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A bidirectional micro pump driven by a double-layer nickel-titanium-based shape memory alloy film, characterized in that: The invention comprises a left cover plate (1), a washer (4), a right cover plate (5), a first shape memory alloy diaphragm (9), a pressing block (10), a second shape memory alloy diaphragm (13) and four copper foils (3); the right cover plate (5) and the left cover plate (1) are arranged opposite to each other; the first shape memory alloy diaphragm (9) and the second shape memory alloy diaphragm (13) are arranged opposite to each other and in parallel between the right cover plate (5) and the left cover plate (1); the washer (4) is arranged at the outer edge between the first shape memory alloy diaphragm (9) and the second shape memory alloy diaphragm (13); the pressing block (10) is arranged at the outer edge between the first shape memory alloy diaphragm (9) and the second shape memory alloy diaphragm (13); A copper foil sheet (3) is provided at the outer side of the upper and lower edges of the first shape memory alloy diaphragm (9) and the second shape memory alloy diaphragm (13) in the middle part between the two sheets (13); a locking assembly is provided between the left cover plate (1) and the right cover plate (5) to press the left cover plate (1), the right cover plate (5), the first shape memory alloy diaphragm (9), the gasket (4), the second shape memory alloy diaphragm (13) and the four copper foil sheets (3); the right cover plate (5) is provided with an outlet first check valve (8) and an inlet first check valve (11); and the left cover plate (1) is provided with an outlet second check valve (14) and an inlet second check valve (12).

2. A bidirectional micro pump driven by a double-layer nickel-titanium-based shape memory alloy film according to claim 1, characterized in that: A sealing ring (2) is provided between the outer edge of the first shape memory alloy diaphragm (9) and the right cover plate (5) and between the outer edge of the second shape memory alloy diaphragm (13) and the left cover plate (1), and the sealing ring (2) is arranged on the outside of the copper foil (3).

3. A bidirectional micro pump driven by a double-layer nickel-titanium-based shape memory alloy film according to claim 2, characterized in that: The sealing ring (2) is made of insulating and heat-insulating elastic material.

4. A bidirectional micro pump driven by a double-layer nickel-titanium-based shape memory alloy film according to claim 1, characterized in that: The locking assembly comprises a plurality of bolts (7) and a plurality of nuts (6); the bolts (7) are evenly distributed along the circumferential direction and respectively pass through the edges of the end faces of the left cover plate (1) and the right cover plate (5); the ends of the bolts (7) are threadedly connected with the nuts (6) for locking.

5. A bidirectional micro pump driven by a double-layer nickel-titanium-based shape memory alloy film according to claim 1, characterized in that: The thickness of the pressing block (10) is greater than the thickness of the gasket (4).

6. A bidirectional micro pump driven by a double-layer nickel-titanium-based shape memory alloy film according to claim 5, characterized in that: The pressing block (10) is cylindrical in shape, and the end faces of the pressing block (10) are in contact with the first shape memory alloy diaphragm (9) and the second shape memory alloy diaphragm (13) respectively.

7. The bidirectional micro pump driven by a double-layer nickel-titanium-based shape memory alloy film according to claim 1, characterized in that: The gasket (4) and the pressing block (10) are made of insulating and heat-insulating materials.

8. The bidirectional micro pump driven by a double-layer nickel-titanium-based shape memory alloy film according to claim 1, characterized in that: The first shape memory alloy diaphragm (9) and the second shape memory alloy diaphragm (13) are both made of a nickel-titanium-based shape memory alloy thin film material that is martensite at room temperature.

9. The bidirectional micro pump driven by a double-layer nickel-titanium-based shape memory alloy film according to claim 1, characterized in that: The outer side of the copper foil (3) extends outwardly in the radial direction to the outside of the first shape memory alloy diaphragm (9) and the second shape memory alloy diaphragm (13).

10. The bidirectional micro pump driven by a double-layer nickel-titanium-based shape memory alloy film according to claim 1, characterized in that: The left cover plate (1), the right cover plate (5), the first shape memory alloy diaphragm (9) and the second shape memory alloy diaphragm (13) are all circular in shape.

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