CN101881779B - Ultrasonic standing wave type micro-fluidic chip and preparation method thereof - Google Patents

Abstract

The invention discloses an ultrasonic standing wave microfluidic chip and a preparation method thereof. Its products are composed of glass slides, microfluidic chips, printed circuit boards (PCB boards), piezoelectric ceramics and control circuits. The microfluidic chip structure contains a standing wave reaction chamber, which is formed by solidifying a liquid polydimethylsiloxane (PDMS) prepolymer through a positive mold template, and placing a glass slide on it before it solidifies, and waits for it to After being solidified and connected as a whole, the mold is demoulded; the front of the PCB board is coated with a conductive layer, which is integrated with the microfluidic chip through the conductive layer and the non-glass slide surface of the microfluidic chip, and the front of the PCB board is provided with The holes corresponding to the structure of the microfluidic chip are equipped with piezoelectric ceramics corresponding to the holes of the standing wave reaction chamber; the control circuit is arranged on the back of the PCB board. The invention has simple manufacturing process, low cost, high controllability and operability, high degree of integration, and easy separation, capture and manipulation of biological living samples such as cells.

Description

An ultrasonic standing wave microfluidic chip and its preparation method

technical field

The invention belongs to the field of micro total analysis system. In particular, it relates to an ultrasonic standing wave microfluidic chip and a preparation method thereof.

Background technique

Microfluidic chip technology was developed in the field of analytical chemistry in the 1990s. It is characterized by micro-networks and life sciences as the main research object. The functions of the entire laboratory include sample pretreatment, reaction, separation, and detection. etc. are integrated on the microchip, which greatly improves the analysis speed, has extremely wide applicability and application prospects, and is the focus of current micro-analysis system research.

At the same time, due to the nondestructiveness of acoustic detection and operation methods for the detection of living biological samples, it has become another research hotspot. At present, in the microfluidic system, the micro-network structure is generally etched on hard materials such as silicon wafers by wet etching, and then the glass wafer is bonded and etched to have a micro-network structure by means of anodic bonding. Structured silicon wafers are used to make acoustic chips. The processing effect of this kind of acoustic wave chip is better, but it needs to use anode bonds and equipment worth millions, so that the cost of the prepared chip is very high, which is not conducive to marketization. In addition, the current acoustic wave chip is still in the laboratory stage, and there is still a lack of research on the operability and controllability of the chip.

Contents of the invention

The object of the present invention is to provide an ultrasonic standing wave microfluidic chip with simple manufacturing process, low manufacturing cost and high integration and its preparation method in view of the above-mentioned prior art.

The technical scheme that realizes the object of the present invention adopts is:

The ultrasonic standing wave microfluidic chip is composed of a glass slide, a microfluidic chip, a printed circuit board (PCB board), piezoelectric ceramics and a control circuit. The microfluidic chip structure includes a standing wave reaction chamber, which is formed by a polydimethylsiloxane (PDMS) liquid prepolymer through a positive mold template, and the glass slide is placed before the liquid prepolymer is solidified. Place it on it, and demould after it is solidified and connected as a whole; there is a conductive layer on the front of the PCB board, which is integrated with the microfluidic chip through the conductive layer and the non-glass slide surface of the microfluidic chip, and Holes corresponding to the structure of the microfluidic chip are provided on the front of the PCB, and piezoelectric ceramics are installed in the holes corresponding to the standing wave reaction chamber; the control circuit is arranged on the back of the PCB.

In practical applications, the number of standing wave reaction chambers on the above-mentioned microfluidic chip can be ≥1, and the hole positions and piezoelectric ceramics on the above-mentioned PCB analysis correspond to it; the corresponding control circuit is a set of switch circuits , the input ends of the switches are connected together, and the output ends of the switches are respectively connected with the piezoelectric ceramics.

The preparation method of the ultrasonic standing wave microfluidic chip consists of the following steps:

1. Prepare the required positive mold template for the microfluidic chip containing the standing glass reaction chamber by soft lithography;

2. On the conductive layer of the printed circuit board (PCB board) with a conductive layer on the surface, the holes corresponding to the structure in the microfluidic chip are processed, and the holes corresponding to the ultrasonic standing wave reaction chamber are processed. Install the piezoelectric ceramic sheet inside, and then lay out the corresponding control circuit on the non-conductive layer of the PCB board;

3. Put the polydimethylsiloxane (PDMS) liquid prepolymer on the positive mold template of the prepared microfluidic chip, and place the glass slide on the PDMS liquid prepolymer on the positive mold template. After the PDMS liquid prepolymer reacts and solidifies, it is released from the mold together to form a microfluidic chip integrated with the glass slide, and punch holes with a puncher;

4. Connect the microfluidic chip integrated with the glass slide through the non-slide layer on it and the conductive layer on the PCB

The prepared PCB boards are connected together correspondingly.

In practical application, the male mold template for preparing the microfluidic chip can be a single crystal silicon male mold template; the holes on the above PCB board where piezoelectric ceramics are installed can be filled with epoxy resin for packaging piezoelectric ceramics.

The sound source of the ultrasonic standing wave in the present invention comes from the piezoelectric ceramic installed in the hole of the PCB, and its operating frequency is determined by its own properties. Depending on the resonance frequency of each piezoelectric ceramic, by adjusting the intensity and frequency of the input signal, the separation and capture of biological samples such as cells can be realized.

The invention realizes the integration of the ultrasonic standing wave in the microfluidic chip by embedding. Compared with the existing method, it has the following advantages: the device has a simple processing process and does not need complicated steps such as wet etching; the cost is low, and expensive anode bonds and equipment are not required in the manufacturing process; the generation of ultrasonic standing wave field and The adjustment is controllable; the device can have a higher degree of integration by using smaller piezoelectric ceramic chips. The invention can easily realize the separation, capture and manipulation of biological living samples such as cells. Accordingly, the present invention can be widely used in the fields of life science, pharmaceutical science, medicine and the like.

Description of drawings:

Fig. 1 is a cross-sectional schematic diagram of the ultrasonic standing wave microfluidic chip of the present invention.

Fig. 2 is a top view of the product of Example 1 of the present invention.

Fig. 3 is a top view of the product of Embodiment 2 of the present invention.

Fig. 4 is a top view of the product of Embodiment 3 of the present invention.

In the drawings: 1—PCB board, 2—PDMS, 3—glass slide, 4—ultrasonic standing wave reaction chamber, 5—PZT piezoelectric ceramic sheet, 6—epoxy resin for encapsulating PZT, 7——The inlet/outlet hole of the chip.

Detailed ways:

Example 1

1. Use the method of soft lithography to prepare the single crystal silicon positive mold template for the ultrasonic standing wave microfluidic chip. Only one standing wave reaction chamber (4) is designed in this template, forming a 1×1 standing wave reaction chamber array;

2. Process a hole corresponding to the structure in the microfluidic chip on the PCB board (1) plated with a layer of copper on the surface, and install and fix the PZ26 piezoelectric ceramic sheet in the hole of the ultrasonic standing wave reaction chamber ( 5), as the sound source of the ultrasonic standing wave, wiring is carried out on the back of the PCB board (1) at the same time, and the input signal of the piezoelectric ceramic sheet (5) is connected to the output end of the control circuit;

3. Pour the PDMS liquid prepolymer (2) on the positive mold template, and then put a glass slide (3) on the PDMS liquid prepolymer (2) on the male mold template. Demoulding, making a microfluidic chip integrated with the glass slide, and punching holes with a puncher;

4. Fix the above-prepared microfluidic chip integrated with the glass slide and the above-prepared PCB board (1) together with screws to obtain a microfluidic chip integrated with an ultrasonic standing wave reaction chamber (4) .

Example 2

1. The glass positive mold template for the ultrasonic standing wave microfluidic chip is prepared by soft lithography. Three standing wave reaction chambers (4) are designed in the template to form a 1×3 standing wave reaction chamber array;

2. Process holes corresponding to the structure in the microfluidic chip on the PCB (1) coated with a layer of platinum on the surface, and install and fix three PZ26 pressure gauges in the holes corresponding to the ultrasonic standing wave reaction chamber. The electric ceramic sheet (5), as the sound source of the ultrasonic standing wave, is wired on the back of the PCB board (1) at the same time, and all the input signals of the piezoelectric ceramic sheet (5) are connected to the output ends of the three-way switch circuit, and Fix the circuit board welded with the three-way switch on both sides of the PCB board (1) as a bracket;

3. Pour the PDMS liquid prepolymer (2) on the positive mold template, and then put a glass slide (3) on the PDMS liquid prepolymer (2) on the male mold template. Demoulding, making a microfluidic chip integrated with the glass slide, and punching holes with a puncher;

4. Fix the above-prepared microfluidic chip integrated with the glass slide and the PCB board (1) with the bracket installed together with screws to obtain a microfluidic chip integrated with three standing wave reaction chambers (4). chip.

Example 3

1. The monocrystalline silicon positive mold template for the ultrasonic standing wave microfluidic chip is prepared by soft lithography, and 9 standing wave reaction chambers (4) are designed in the template to form a 3×3 array distribution;

2. Process holes corresponding to the structure in the microfluidic chip on the PCB plated with a layer of gold on the surface, and install and fix nine PZ26 pressure sensors in the holes of the ultrasonic standing wave reaction chamber (4). The electric ceramic sheet (5), as the sound source of the ultrasonic standing wave, is wired on the back side of the PCB board (1) at the same time, and all the input signals of the piezoelectric ceramic sheet (5) are connected to the output ends of the nine-way switch circuit, and Fix the circuit board welded with the nine-way switch on both sides of the PCB board (1) as a bracket;

3. Pour the PDMS liquid prepolymer (2) on the positive mold template, and then put a glass slide (3) on the PDMS liquid prepolymer (2) on the male mold template. Demoulding, making a microfluidic chip integrated with the glass slide, and punching holes with a puncher;

4. Fix the above-prepared microfluidic chip integrated with the glass slide and the PCB board (1) with the bracket installed together with screws, that is, a 3×3 total of 9 standing wave reaction chambers ( 4) The microfluidic chip.

Claims (5)

1. a ultrasonic standing wave type micro-fluidic chip is made up of microslide, micro-fluidic chip, printed circuit board (PCB), piezoelectric ceramics and control circuit, it is characterized in that:

1) includes the standing wave reaction chamber in the described microfluidic chip structure, pass through the moulding of formpiston template, and before its liquid prepolymer is solidified, described microslide is placed on it, treat its back demoulding that is cured as a single entity by the dimethyl silicone polymer liquid prepolymer;

2) has one deck conductive layer on the front of said printed circuit board (PCB); Its non-microslide aspect and micro-fluidic chip through this conductive layer and micro-fluidic chip fuses; And the front of printed circuit board (PCB) is provided with and position, the corresponding hole of microfluidic chip structure, and the position, hole of its corresponding standing wave reaction chamber is equipped with piezoelectric ceramics;

3) described control circuit is laid in the back side of printed circuit board (PCB).

2. a kind of ultrasonic standing wave type micro-fluidic chip according to claim 1 is characterized in that: described control circuit is one group of on-off circuit; The input end of its switch connects together, and the output terminal of its switch links to each other respectively with each piezoelectric ceramics.

3. the preparation method of a ultrasonic standing wave type micro-fluidic chip is characterized in that being made up of following step:

1) method with soft lithographic prepares the formpiston template that the required micro-fluidic chip that contains reaction chamber in the glass is used;

2) the surface have process on the conductor planes on the printed circuit board (PCB) of one deck conductive layer with micro-fluidic chip in position, the corresponding hole of structure; And, then on the non-conductive aspect of printed circuit board (PCB), lay correspondent control circuits piezoelectric ceramic piece being installed with the corresponding Kong Weili of ultrasonic standing wave reaction chamber;

3) the dimethyl silicone polymer liquid prepolymer is inserted on the formpiston template of micro-fluidic chip of preparation; And microslide is placed on the dimethyl silicone polymer liquid prepolymer on the formpiston template; After treating that the reaction of dimethyl silicone polymer liquid prepolymer is solidified; The demoulding together, the micro-fluidic chip of formation and microslide one punches with card punch;

4) will link together accordingly through the non-microslide aspect on it and the conductor planes on the printed circuit board (PCB) and the printed circuit board (PCB) of preparation with the micro-fluidic chip of microslide one.

4. the preparation method of a kind of ultrasonic standing wave type micro-fluidic chip according to claim 3, it is characterized in that: the formpiston template that described preparation micro-fluidic chip uses is the silicon mold template.

5. according to the preparation method of claim 3 or 4 described a kind of ultrasonic standing wave type micro-fluidic chips, it is characterized in that the Kong Weili that piezoelectric ceramics is installed on the described printed circuit board (PCB) is filled with the epoxy resin that encapsulates piezoelectric ceramics.

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