CN104083930B - A kind of filtrating chip and processing and fabricating method thereof - Google Patents

Abstract

The invention relates to a filter chip and a manufacturing method of the filter chip, belonging to the fields of environment, food, chemical industry, medicine and the like. The chip includes a substrate with a filter structure, an upper cover, a forward sample inlet, a forward sample outlet, a reverse backflush inlet, and a reverse backflush outlet. One side of the chip is arranged in order from near to far. Next to the reverse backflush sample port and forward sample inlet connected to the filter structure, the other side of the chip is arranged in sequence from near to far with the forward sample outlet and reverse backflush respectively connected to the filter structure. Inlet, the filter structure is composed of a series of micro-nano cylinders with gaps in a columnar array, divided into inner filter structure and outer filter structure, the substrate with filter structure and the upper cover are distributed on the substrate The fixed columns inside the inner filter structure are bound together with the fixed columns outside the outer filter structure. The invention has high recovery rate, can withstand high flow rate, low cost, is suitable for large-scale mass production, and can be widely used in the filtration and concentration of microparticles in the fields of water, food and microorganisms.

Description

A filter chip and its manufacturing method

technical field

The invention relates to a filter chip and a processing and manufacturing method thereof, belonging to the fields of environment, food, chemical industry, medicine and the like.

Background technique

As a common filtration membrane, micro-nano filters are widely used in the fields of microbial analysis in drinking water, sterile filtration of wine and fruit juice, and sterile drug screening. According to the working mode, micro-nano filters can be divided into dead-end filtration and cross-flow filtration. Dead-end filtration is to place the sample to be filtered directly above the filter, and driven by the pressure difference, particles larger than the typical pore size of the filter are trapped on the membrane. With the passage of time, the filter is easy to be blocked by particles on the surface of the membrane, which increases the filtration resistance. The cross-flow filtration mode produces two component forces on the surface of the membrane. The normal force perpendicular to the flow direction makes the sample pass through the filter gap, and the tangential force along the flow direction makes the trapped particles more evenly scattered. This kind of filter membrane is not easy to produce concentration polarization. and fouling problems. The current main fabrication methods of micro-nano filters include silicon surface micromachining method, phase separation micromolding method and aperture array photolithography method. The problems and deficiencies of these methods are: there are problems such as collapse or damage during demoulding, and the filter has low strength, high cost and low yield.

A typical application of micro-nano filters is for the filtration and concentration of particulate matter in water, such as the eggs of water-borne parasites Cryptosporidium and Giardia. Currently, the standard detection method for cryptosporidium parasites and giardia parasites in drinking water is the EPA 1623 method formulated by the US Environmental Protection Agency (USEPA). The EPA 1623 method mainly includes steps such as filtration and elution, concentration and separation, immunofluorescence labeling, and fluorescence microscopy analysis. This method is mature and highly recognized, but it also has its limitations: it takes 3-7 days, high cost, cumbersome steps, and is easily affected by cross-reaction of algae in water, and the recovery rate is not high. Due to the limitations of the manufacturing process, the polymer filter used in the EPA 1623 method cannot withstand high flow rates and cannot automatically recover the trapped microorganisms. It must be manually oscillated and eluted, resulting in low recovery and high cost.

Contents of the invention

The object of the present invention is to propose a filter chip and a method for making the filter chip in view of the disadvantages of the above-mentioned prior art.

In order to achieve the above purpose, the technical solution adopted by the present invention is to make the filter chip include a substrate with a filter structure, an upper cover, a forward sample inlet, a forward sample outlet, a reverse backflush inlet, a reverse backflush The sample outlet, one side of the chip is arranged in sequence from near to far with reverse backflush outlet and forward inlet which are respectively connected to the filter structure, and on the other side of the chip are arranged in turn from near to far respectively connected to the filter structure. The connected positive sample outlet and reverse filter structure are composed of a series of micro-nano cylinders with gaps in a columnar array, which are divided into inner filter structure and outer filter structure. The substrate with filter structure and the upper cover pass through The anchor posts on the unetched part of the substrate are firmly bound together.

Specifically, the gap between the inner filter structure and the outer filter structure is non-uniform design; the micro-nano column can be square, cylindrical, trapezoidal, raindrop-like, or other similar shapes;

Further, the size of the gap between the inner filter structure and the outer filter structure is staggered; the substrate is silicon or glass.

The manufacturing method of filter chip of the present invention comprises the following steps:

The first step is to make a soft template with micro-nano gaps with a monomolecular anti-sticking layer;

The second step is to spin-coat the transition glue layer on the substrate and then coat the embossed photoresist layer to make the substrate;

The third step is to align the soft template with the embossed photoresist layer on the substrate, transfer the pattern on the soft template to the imprinted glue, and form micro-nano pillars composed of the imprinted photoresist;

The fourth step is to sequentially remove the residual imprinted photoresist layer between the micro-nano pillars and the transition layer under the residual imprinted photoresist layer between the micro-nano pillars by using a reactive ion etching process to expose the substrate;

The fifth step is to evaporate a thin metal layer on the surface of the sample by electron beam evaporation, and use acetone solution to clean the transition adhesive layer on the surface of the substrate and the embossed adhesive layer and thin metal layer on it to leave the thin metal layer on the substrate surface. layer as a mask layer;

Step 6: Using the thin metal layer as a mask, the substrate is etched by an inductively coupled plasma etching process, and then the mask layer is removed with a cleaning solution to obtain a corresponding pattern and structure on the substrate.

Further, in the manufacturing method of the filter chip, the metal used in the thin metal layer is nickel.

The beneficial effects of the invention are: the micro-nano filtration chip has high recovery rate, can withstand high flow rate, low cost, is suitable for large-scale mass production, and can be widely used in the filtration and concentration of micro-particles in the fields of water, food and microorganisms.

Description of drawings:

The present invention will be further described below in conjunction with accompanying drawing.

Fig. 1 is a structural schematic diagram one of the present invention;

Fig. 2 is a structural schematic diagram two of the present invention;

Fig. 3 is a cross-sectional view of the filtering microstructure;

Fig. 4 is the second cross-sectional view of the filtering microstructure;

Fig. 5 is the third cross-sectional view of the filtering microstructure;

Figure 6 is a cross-sectional view of the filter microstructure four;

Fig. 7 is a schematic diagram of the embossing manufacturing process;

Detailed ways

The present invention will be further described in detail below in combination with specific embodiments.

The filter chip device of the present embodiment is as shown in Figure 1-6, comprises the substrate 15 that the silicon that has filtering structure 5 and 9 is made, glass upper cover 16, forward sample inlet 1, forward sample outlet 3, Reverse backflush inlet 4, reverse backflush outlet 2, reverse backflush outlet 2, forward inlet 1 respectively connected to the filter structure are arranged in order from near to far on the chip side On the other side of the chip, forward sample outlet 3 and reverse backflush inlet 4 respectively connected to the filter structure are arranged in order from near to far. The filter structures 5 and 9 are composed of a series of micro-nano Composed of cylinders 17, it is divided into an inner filter structure 5 and an outer filter structure 9. The substrate with the filter structure and the upper cover pass through the fixed columns 13 distributed inside the inner filter structure and the fixed columns outside the outer filter structure on the substrate. 14 bound together. 13 and 14 are unetched areas in the chip, which provide guidance for flow samples, increase the bonding contact area, and improve the pressure resistance of the chip. When the chip is working, the large-volume sample to be filtered and concentrated enters from 1, and the filtered clean water sample flows out from 3. When filtering, the particles in the flow sample near the inner filter structure 6 (the gap is larger than the particle diameter) can leave the large gap here and be captured by the peripheral filter structure 10 (the gap is smaller than the particle diameter). Particles in the inner filter structure 7 are directly trapped (gap smaller than particle diameter). The principle of particle capture at other positions can be deduced by analogy. After the particles are captured, use a small amount of deionized water to reversely flush the chip from 4, and the captured particles are released to achieve the purpose of filtration and concentration.

Specifically, the gap between the inner filter structure 5 and the outer filter structure 9 is non-uniform; the micro-nano column 17 can be square, cylindrical, trapezoidal, raindrop-like, or other similar shapes;

Further, the size of the gap between the micro-nano cylinders 17 in the inner filter structure 5 and the outer filter structure 9 is staggered; as 6 of the inner filter layer is a large gap, 10 of the outer filter layer is a small gap; 7 of the inner filter layer 11 of the outer filter layer is a large gap; 8 of the inner filter layer is a large gap, and 12 of the outer filter layer is a small gap.

As shown in Figure 7, making the filter chip is carried out according to the following steps:

The first step is to make an elastic support layer with a monomolecular anti-adhesive layer on the surface, a hard structure layer, and a soft template 23 with micro-nano gap patterns;

Second step, on the silicon substrate 15, spin-coat the transition glue layer PMMA layer 22 and then coat the embossed photoresist layer UV layer 21 to make the substrate;

The third step is to align the UV layer of the soft template and the substrate and transfer the pattern on the soft template to the embossing glue to form micro-nano pillars composed of embossing photoresist;

The fourth step is to sequentially remove the UV layer residue between the micro-nano pillars and the PMMA layer under the UV layer residue between the micro-nano pillars by using a reactive ion etching process to expose the substrate;

The fifth step is to vapor-deposit metal nickel 25 on the surface of the sample by electron beam evaporation process, and use acetone solution to clean the UV layer on the surface of the substrate and the imprinting glue and metal nickel on it, so that the metal nickel on the surface of the substrate is left as a mask. film layer;

The sixth step is to use metal nickel as a mask to etch the substrate by an inductively coupled plasma etching process, and then use a cleaning solution to remove the mask layer to obtain a corresponding pattern and structure on the substrate.

The present invention is not limited to the above-mentioned embodiments, and all technical solutions formed by equivalent replacements fall within the scope of protection required by the present invention.

Claims (5)

1. A filter chip, characterized in that: the chip includes a substrate with a filter structure, an upper cover, a forward sample inlet, a forward sample outlet, a reverse backflush sample inlet, a reverse backflush out The sample port, one side of the chip is arranged in sequence from near to far, the reverse backflush sample port and the forward sample port are respectively connected to the filter structure, and the other side of the chip is arranged in sequence from near to far, respectively connected to the filter structure The forward sample outlet and the reverse backflush inlet are connected. The filter structure is composed of a series of micro-nano cylinders with gaps in a columnar array, which are divided into an inner filter structure and an outer filter structure. The substrate and the upper cover are bound together through the fixed columns distributed inside the inner filter structure on the substrate and the fixed columns outside the outer filter structure; the gap between the inner filter structure and the outer filter structure is non-uniform design, and the inner filter structure The size of the gap with the outer filter structure is arranged in a staggered manner. 2. A filter chip according to claim 1, characterized in that: the micro-nano cylinders are square, cylindrical, trapezoidal or raindrop-like. 3. A filter chip as claimed in claim 1, characterized in that: said substrate is silicon or glass. 4. A method for processing a filter chip as claimed in claim 1, characterized in that it comprises the following steps: The first step is to make a soft template with micro-nano gaps with a monomolecular anti-sticking layer; The second step is to spin-coat the transition layer on the substrate and then apply the imprint photoresist layer; The third step is to align the soft template with the embossed photoresist layer on the substrate, transfer the pattern on the soft template to the imprinted glue, and form micro-nano pillars composed of the imprinted photoresist; The fourth step is to sequentially remove the residual imprinted photoresist layer between the micro-nano pillars and the transition layer under the residual imprinted photoresist layer between the micro-nano pillars by using a reactive ion etching process to expose the substrate; The fifth step is to evaporate a thin metal layer on the surface of the sample by electron beam evaporation, and use acetone solution to clean the transition layer on the surface of the substrate and the imprinted photoresist layer and thin metal layer on the surface of the substrate to leave the surface of the substrate. A thin metal layer as a mask layer; Step 6: Using the thin metal layer as a mask, the substrate is etched by an inductively coupled plasma etching process, and then the mask layer is removed with a cleaning solution to obtain a corresponding pattern and structure on the substrate. 5. The manufacturing method of a filter chip as claimed in claim 4, wherein the metal used in the thin metal layer is nickel.