CN108355726A - A kind of interdigitation speedup Micropump chip based on the driving of AC Electric Heater effect - Google Patents

Abstract

The present invention discloses a kind of interdigitation speedup Micropump chip driven based on AC Electric Heater effect, including channel cover plate, substrate, temperature control groove and electrode pair；The restriction of fluid mass may be implemented in channel cover plate；The size ratio of interdigital electrode pair is 1:1‑1:100, in the case where applying alternating current to electrode, fluid can be driven to be flowed from small electrode direction to large electrode direction under AC Electric Heater effect.Cooling groove and heating groove with fluid is respectively set in the position below substrate corresponding to electrode, cooling piece and resistance wire are placed respectively to realize the generation of channel interior temperature gradient, greatly enhance AC Electric Heater effect, to realize the promotion of the fluid-flow rate under same alternating voltage, improve the low problem of the pump rate of the interdigital electrode chip without temperature offset.Interdigitation speedup Micropump chip manufacturing of the present invention is easy, safe to use, on the basis of ensureing high-precision, has the characteristics that saving reagent, easy to carry.

Description

An interdigitated speed-up micropump chip driven by AC electrothermal effect

technical field

The invention relates to the technical field of microbial chips, and relates to a micropump chip for increasing fluid flow rate, in particular to an interdigitated speed-up micropump chip driven by alternating current electrothermal effect.

Background technique

With the development of modern technology, the precision of the products produced is getting higher and higher, and the experimental operation process is becoming more and more cumbersome. The previous method of using syringe pumps for fluid pumping has been gradually replaced by some microfluidic chips operated by electrokinetic principles. . Microfluidic chips have been widely used because of their high precision, easy operation, easy manufacture, and cost-saving reagents.

For interdigitated electrodes, because the electrodes are distributed in parallel, they are also called parallel electrodes. The four main parameters are: number of pairs of interdigitated electrodes, interdigital width, gap distance between adjacent interdigitated fingers, and thickness of the interdigitated electrodes. Among them, the greater the aspect ratio of the fingers, the greater the density of the fingers, and the greater the speed; reducing the distance between the electrodes of the fingers can also effectively increase the speed; the thicker the electrodes, the smaller the electric field strength, and the thinner the electrodes, the greater the speed. The stronger the electric field, the greater the electric field force, and the electrode edge and gap form a non-uniform electric field area. Providing an AC voltage can make the fluid generate better electrothermal flow, and the fluid flows from the direction of the small electrode to the direction of the large electrode.

Alternating Cμrrent electrothermal (ACET) is mainly used in the drive of fluids with higher conductivity. The AC electrothermal effect is based on the Joule heat of the fluid and the temperature gradient brought about by the small size range. For a fluid with a conductivity greater than 100mS/m, under the action of an alternating electric field with a frequency higher than 100kHz, the Joule heating effect is enhanced, which leads to a change in the properties of the fluid, so that the fluid generates electrothermal flow. Therefore, increasing the input heat to increase the internal temperature gradient of the fluid, changing the voltage, and improving the fluid's physical strength can all increase the flow rate of the fluid. Among them, if the voltage is too large, it may cause the detection cells or particles in the fluid to be damaged and inactivated; if the volume heat is too large, the activity may be reduced; applying an external temperature gradient can improve the electrothermal flow velocity and flow direction in the microfluidic chip. and eddy currents. On this basis, the pumping effect of a higher flow rate can be achieved only by applying the same alternating current.

Contents of the invention

In order to solve the deficiencies of the prior art, the present invention provides an interdigital speed-up micropump chip driven by alternating current electrothermal effect. The invention designs an interdigitated high-efficiency fluid-driven micropump chip, provides a high-efficiency fluid-driven method, solves the problem of low flow rate of the common interdigitated electrode micropump chip, saves time and improves efficiency. It is characterized by adjustable speed and high precision, which ensures the accuracy and practicability of detection.

The technical solution adopted in the present invention is: design an interdigitated speed-up micropump chip driven by AC electrothermal effect, including a channel cover, a substrate, a temperature control groove and an electrode pair; the electrode pair is arranged on the substrate The upper surface of the channel cover sheet is closely attached to the upper surface of the substrate, and a temperature control groove is arranged under the substrate.

The channel cover is a plate-shaped structure, and its upper surface is provided with two through holes connected with the lower surface, which are respectively an inlet channel and an outlet channel; its lower surface is provided with a concave rectangular notch, which is an internal channel, and the inlet channel The outlet channel communicates with the internal channel; the substrate is arranged under the channel cover and is in close contact with its lower surface, and the upper surface of the substrate covers the internal channel; the lower surface of the substrate is in close contact with the upper surface of the temperature control groove ; Electrode pairs are arranged inside the internal channel and adhered to the upper surface of the substrate.

The electrode pair includes a small electrode and a large electrode. Both the small electrode and the large electrode have a structure in which the main body extends outwards vertically. The branch of the small electrode is smaller than that of the electrode. branches intersect and do not touch each other.

The upper surface of the temperature control groove is provided with staggered and disconnected inner grooves, the two ends of the inner grooves are located on the outside of the substrate, one end is a heating groove, and the other end is a cooling groove; the heating groove and the cooling groove are both Comb-shaped, relatively staggered and disconnected, the sub-channels of the heating tank respectively correspond to the branches of the small electrodes and are located directly below them; the sub-channels of the cooling tank respectively correspond to the branches of the large electrodes and are located directly below them.

The present invention has the following characteristics:

(1) The pumping speed of the fluid in the chip is accelerated, and the required time is greatly shortened;

(2) To achieve the goal by changing the temperature gradient, the temperature control method is very simple, making the experiment simple and completed;

(3) The chip has a simple structure and low processing difficulty.

Compared with the prior art, the beneficial effect of the present invention lies in that the microfluid pumping chip designed by the present invention can control the temperature of the heat-conducting fluid in the groove by respectively adding resistance wires and refrigeration sheets in the temperature-controlled groove, and can control the temperature of large While the electrodes dissipate heat, the small electrodes are heated up to obtain the effect to be achieved. The pumping chip designed by the invention is easy to install, and on the basis of ensuring high precision, it has the characteristics of convenience, quickness, high efficiency and the like.

Description of drawings

Fig. 1 is a schematic diagram of the overall structure of an embodiment of the present invention;

Fig. 2 is a schematic diagram of the structure of interdigitated electrodes according to an embodiment of the present invention;

Fig. 3 is a schematic diagram of the structure of a temperature-controlled trench according to an embodiment of the present invention;

Fig. 4 is a schematic cross-sectional structure diagram of an embodiment of the present invention.

Detailed ways

The specific implementation of the present invention will be described in detail below in conjunction with accompanying drawings 1-4.

An interdigitated speed-up micropump chip driven by AC electrothermal effect designed in the present invention includes a channel cover 1 , a substrate 2 , a temperature control groove 3 and an electrode pair 4 . The electrode pair 4 is arranged between the channel cover sheet 1 and the substrate 2 , and is closely attached to the upper surface of the substrate 2 , and a water tank 3 is arranged below the substrate 2 .

The channel cover 1 is a plate-like structure, and its upper surface is provided with two through holes connected with the lower surface, which are respectively the inlet channel 11 and the outlet channel 13; its lower surface is provided with a concave rectangular notch, which is an internal channel. 12 , the inlet channel 11 and the outlet channel 13 communicate with the inner channel 12 . The substrate 2 is arranged under the channel cover 1 and is in close contact with the lower surface thereof, and the upper surface of the substrate 2 covers the internal channel 12 . The lower surface of the substrate 2 is in close contact with the upper surface of the temperature control groove 3 . The electrode pairs 4 are arranged inside the internal channel 12 and adhered to the upper surface of the substrate 2 .

The electrode pair 4 includes a small electrode 41 and a large electrode 42. The small electrode 41 and the large electrode 42 both have a structure in which the main body extends outwards vertically. The branch of the small electrode 41 is smaller than that of the electrode 42. The small electrode 41 Set opposite to the large electrode 42 , the branches of the two are interlaced and do not touch each other.

The upper surface of the temperature control groove 3 is provided with staggered and disconnected inner grooves, the two ends of the inner grooves are located outside the substrate 2 , one end is a heating groove 31 , and the other end is a cooling groove 32 . The heating tank 31 and the cooling tank 32 are comb-shaped, relatively staggered and not connected. The sub-channels of the heating tank 31 correspond to the branches of the small electrodes 41 and are located directly below them; The branch of the electrode 42 corresponds to and is located directly below it.

The electrode pair 4 is an interdigitated electrode pair with a width ratio of 1:1-1:100.

As shown in accompanying drawings 1-4, the small electrode 41 and the large electrode 42 are respectively provided with 3 branches, and correspondingly, the heating tank 31 and the cooling tank 32 are respectively provided with 3 sub-channels, and the width of each channel is the same as The lengths respectively correspond to the branches of the corresponding electrodes.

The channel 12 is rectangular, with a side length of 1-20 mm and a height of 10-100 μm.

The electrode pairs 4 are made of conductive metal materials such as gold or ITO, with a size of 1-500 μm and a logarithm of 1-100 pairs.

The material of the substrate 2 can be other materials such as silicon, glass, polymer, etc., preferably glass or silicon, and the size is combined with a glass slide.

In order to better dissipate heat, the temperature control groove 3 can be made of other materials such as glass, polymer, silicon, etc., preferably PDMS. The temperature control groove is a square structure with a side length of 1-20mm and a height of 1-10mm. The fluid used for temperature control inside is a fluid with good thermal conductivity, preferably heat-conducting oil. The groove size is 1-500 μm.

Through the heating tank 31 and the cooling tank 32 corresponding to the lower part of the substrate where the electrode is located, a resistance wire is placed in the heating tank 31 to heat the small electrode, and a cooling plate is placed in the cooling tank 32 to dissipate heat for the large electrode, thereby enlarging the channel The temperature gradient of the fluid in the medium is used to promote the circulation of the fluid.

The working principle and process of the present invention are as follows: the fluid is injected from the inlet channel 11, and during the flow process from the channel 12 to the outlet channel 13, an alternating current is applied to the electrodes 41 and 42, the electrodes generate alternating heat, the temperature gradient is generated, and the alternating electric heating effect is generated. The direction of the small electrode 41 points to the large electrode 42, driving the fluid to flow to 13, adding a resistance wire to the heat transfer oil at 31 to heat the small electrode, and adding a cooling sheet to the heat transfer oil at 32 to cool down the large electrode, so that the temperature gradient is further increased Larger, so that the AC electrothermal effect is stronger, and the efficiency improvement time of the fluid flowing to the outlet channel 13 is greatly shortened, which can well ensure the stability of the pumping effect.

Utilize the technical solution described in the present invention, or those skilled in the art design a similar technical solution under the inspiration of the technical solution of the present invention, and achieve the above-mentioned technical effect, all fall into the protection scope of the present invention.

What is not mentioned in the present invention is applicable to the prior art.

Claims (10)

1. a kind of interdigitation speedup Micropump chip based on the driving of AC Electric Heater effect, which is characterized in that including channel cover plate, base Piece, temperature control groove and electrode pair；The electrode is to being arranged in substrate upper surface, and the lower surface of channel cover plate and substrate upper surface It is tightly bonded, temperature control groove is provided with below substrate；

The channel cover plate is platy structure, and upper surface is provided with two through-holes penetrated through with lower surface, and respectively entrance is logical Road and exit passageway；Its lower surface is provided with indent rectangular notch, is that inner passage, access road and exit passageway and inside are logical Road is connected to；Substrate setting is close to below channel cover piece, and with its lower surface, and the upper surface of substrate covers inner passage；Substrate Lower surface and the upper surface of temperature control groove be close together；Electrode sticks in substrate to being arranged in the inside of inner passage Upper surface on；

For the electrode to including small electrode and large electrode, the small electrode and large electrode are the protruding branch of body normal Structure, branch's larger electrode of small electrode it is small, small electrode is oppositely arranged with large electrode, and the branch of the two is interlaced and does not connect It touches；

The upper surface of temperature control groove is provided with staggeredly and disconnected indent conduit, the both ends of the indent conduit are located at the outer of substrate Side, one end are heating tank, and the other end is cooling slot；Heating tank is in pectination with cooling slot, and staggered relative is arranged and is not connected to, adds Heat channel divides conduit corresponding with the branch of small electrode respectively and immediately below it；Cooling slot divide conduit respectively with large electrode Branch is corresponding and immediately below it.

2. a kind of interdigitation speedup Micropump chip based on the driving of AC Electric Heater effect according to claim 1, feature It is, the electrode is to for interdigital structure, width ratio ranging from 1:1-1:100.

3. a kind of interdigitation speedup Micropump chip based on the driving of AC Electric Heater effect according to claim 1, feature It is, the channel cover plate is rectangle, and length of side 1-20mm is highly 1-100 μm.

4. a kind of interdigitation speedup Micropump chip based on the driving of AC Electric Heater effect according to claim 1, feature It is, the channel patch material is one kind in glass, polymer, silicon.

5. a kind of interdigitation speedup Micropump chip based on the driving of AC Electric Heater effect according to claim 1, feature It is, the electrode is 1-500 μm to using conductive metallic material, size, and logarithm is 1-100 pairs.

6. a kind of interdigitation speedup Micropump chip based on the driving of AC Electric Heater effect according to claim 5, feature It is, the electrode is to using gold or ITO.

7. a kind of interdigitation speedup Micropump chip based on the driving of AC Electric Heater effect according to claim 1, feature It is, the material of substrate is one kind in silicon, glass, polymer, size combination glass slide.

8. a kind of interdigitation speedup Micropump chip based on the driving of AC Electric Heater effect according to claim 1, feature It is, the temperature control trench material is one kind in glass, polymer, silicon.

9. according to a kind of interdigitation speedup Micropump core based on the driving of AC Electric Heater effect of 1,4,7 any one of them of claim Piece, which is characterized in that the material of the channel cover plate and temperature control groove is PDMS.

10. a kind of interdigitation speedup Micropump chip based on the driving of AC Electric Heater effect according to claim 1, feature It is, resistance wire is placed in the heating tank of temperature control groove and is used to heat to small electrode, and placing cooling piece in the slot that cools down is used for big Electrode radiates, and the internal fluid for temperature control is conduction oil.