Simple pore drilling and hole expanding device and method for aperture-controllable nanopore on thin-film chip

Abstract

The application discloses a simple pore drilling and reaming device and method for controllable aperture nanometer holes on a thin film chip, which comprises a liquid pool one, a liquid pool two, a liquid pool three, a direct current voltage module, a clamp, a standard nanometer hole chip and a to-be-processed thin film chip; the standard nanometer hole chip clamp plate is clamped between the liquid pool one and the liquid pool two, the to-be-processed thin film chip is arranged between the liquid pool two and the liquid pool three, the liquid pool one, the liquid pool two and the liquid pool three are fixed on the clamp through screws, and the direct current voltage module outputs a constant voltage; the application does not need to use a computer system and a digital source table to monitor current feedback control bias voltage, and controllable nanometer hole manufacturing can be realized by using the constant direct current voltage module; only by selecting a direct current voltage value and a standard nanometer hole chip, setting a manufacturing time, and then different aperture nanometer holes can be stably manufactured on the to-be-processed thin film chip, and an experimental personnel does not need to confirm nanometer hole size through current feedback, so that the experimental cost and difficulty of the control breakdown pore drilling method are reduced.

Description

Technical Field

[0001] This invention relates to the field of medical and micro / nano sensing technology, and more particularly to a simple device and method for fabricating and expanding nanopores with controllable pore size on thin-film chips. Background Technology

[0002] Solid-state nanopores have seen rapid development over the past few decades due to their flexible size, structure, and good chemical stability. They have already found widespread commercial applications as single-molecule sensors in fields such as DNA sequencing and protein analysis, and hold promise for early pathological diagnosis and personalized medicine. With advancements in materials science and semiconductor manufacturing processes, significant breakthroughs have been achieved in the fabrication of solid-state nanopores. Traditional methods for fabricating nanopores, such as focused ion beam, focused electron beam, laser etching, chemical etching, and the drawing of glass or quartz nanoparticles, are costly and technically challenging. In recent years, controlled breakdown technology has gradually become the preferred method for low-cost fabrication of solid-state nanopores.

[0003] Current controlled breakdown techniques apply a constant, ramp, or pulsed voltage to liquid pools at both ends of a thin-film chip. The resulting redox reactions and carrier tunneling under the influence of the electric field lead to the formation of defects in the thin film. Once the defect's connection path crosses the film, breakdown occurs, forming a nanopore. However, the fabrication process requires a high-precision, high-frequency digital source meter and computer program to monitor subtle changes in the transmembrane current (from picoamperes to nanoamperes) in real time. The voltage must be switched off at the moment of a sudden current change to prevent the nanopore from becoming too large or the film from rupturing due to a sustained high electric field. Therefore, the equipment cost and technical barriers of this method remain high, limiting its widespread application in nanopore fabrication. Summary of the Invention

[0004] To address the aforementioned problems, this invention aims to provide a simple apparatus and method for fabricating nanopores and enlarging pore size on a thin-film chip using a constant DC voltage. The apparatus comprises three liquid pools: pool one and pool two are separated by the thin-film chip to be processed, and pool two and pool three are separated by a standard nanopore chip. Electrodes are placed in pools one and three, and a DC voltage is applied. The equivalent circuit is a series connection between the thin-film chip to be processed and the standard nanopore chip. At this point, the resistance of the thin-film chip to be processed is essentially infinite, and the entire voltage is applied across its terminals. When the thin film is broken down to create a nanopore, its resistance drops rapidly. According to the voltage division principle of a series circuit, the standard nanopore chip shares part of the voltage at the moment of breakdown, causing the voltage applied across the thin-film chip to decrease instantaneously. Furthermore, as the pore size increases, the voltage applied across the thin-film chip also decreases. Therefore, as processing time progresses, the pore size of the nanopore gradually stabilizes and no longer increases. The voltage change across the thin-film chip to be processed is directly related to the resistance value of the standard nanopore chip. Therefore, the specific pore size can be controlled by selecting standard chips containing nanopores of different sizes and adjusting the DC voltage. Because the nanopores in standard chips are relatively thick and their pore size is not easily changed, they can be reused repeatedly. This device can achieve controllable fabrication of nanopores without a voltage feedback control system, simplifying the experimental setup, reducing experimental costs, and minimizing the time required by researchers.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a simple device for manufacturing nanopores with controllable aperture on a thin-film chip using DC voltage. The device includes a liquid pool one, a liquid pool two, a liquid pool three, a DC voltage module, a fixture, a screw one, a screw two, a rubber washer, and a chip clamping plate. The chip clamping plate is sandwiched between the liquid pool one and the liquid pool two, and the thin-film chip to be processed is placed between the liquid pool two and the liquid pool three. The liquid pool one, the liquid pool two, and the liquid pool three are fixed to the fixture by screws, and the liquid pool two is placed between the liquid pool one and the liquid pool three. The DC voltage module outputs a constant voltage.

[0006] In this invention, a chip clamp is sandwiched between liquid pool one and liquid pool two, and standard nanoporous chips with a thickness of 100-1000 nm are installed in the two chip clamps. The nanoporous materials include, but are not limited to, silicon nitride, silicon oxide, and aluminum oxide. A thin film chip with a thickness of 5-30 nm to be processed is installed between liquid pool two and liquid pool three. The thin film materials include, but are not limited to, silicon nitride, silicon oxide, aluminum oxide, graphene, molybdenum disulfide, and boron nitride. The chip clamp is installed in the sliding grooves of liquid pool one and liquid pool two.

[0007] In this invention, liquid pool one, liquid pool two, and liquid pool three are fixed in placement slots on a fixture by screw one and screw two. Screw one fixes liquid pool one, liquid pool two, and liquid pool three in the placement slots of the fixture in the horizontal direction, and screw two fixes liquid pool two and liquid pool three in the placement slots of the fixture in the vertical direction. The DC voltage module output electrode is inserted into liquid pool one and liquid pool three to provide a constant voltage. The chip clamp is located in the sliding groove of liquid pool one and liquid pool two, in which standard nanoporous chips of different pore sizes are installed. The rubber gaskets are respectively adhered between the contact surfaces of liquid pool one, liquid pool two, and liquid pool three.

[0008] This invention provides a simple apparatus and method for fabricating nanopores and enlarging pore size on a self-supporting thin-film chip using a direct current voltage. The method is as follows:

[0009] 1) Place liquid pool one, liquid pool two and liquid pool three in sequence on the placement slot of the fixture. Place the thin film chip to be processed between the rubber gaskets of liquid pool two and liquid pool three. Rotate screw two to clamp liquid pool two and liquid pool three. Place standard nanopore chips with different pore sizes in the chip clamping plate. Place the chip clamping plate in the sliding groove of liquid pool one and liquid pool two. Rotate screw one to clamp liquid pool one.

[0010] 2) Inject an electrolyte solution of a certain concentration into liquid pool one, liquid pool two and liquid pool three, and use the sliding chip clamp to select a standard nanopore chip to control the pore size of the processed nanopores.

[0011] 3) Insert the output electrode of the DC voltage module into the solutions in liquid pool one and liquid pool three, output voltage, and perform hole making. After a period of time, the hole making is completed, and the DC voltage is turned off.

[0012] The beneficial effects of this invention are as follows: This invention proposes a simple device and method for fabricating nanopores with controllable dimensions on thin-film chips using DC voltage. Compared with existing technologies, this method can achieve nanopore fabrication using a DC voltage module without requiring a high-precision, high-frequency digital source meter or voltage and current feedback control software. During the fabrication process, this method only requires selecting a DC voltage value and a standard nanopore chip connected in series. After a fixed time, nanopores of different diameters can be stably fabricated. It eliminates the need for experimental personnel to confirm the completion of aperture expansion through current feedback, thus improving the efficiency of nanopore fabrication, reducing manufacturing costs and technical barriers, and minimizing equipment limitations. The overall device is simple and easy to operate, and has broad market prospects. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the overall assembly structure of the present invention;

[0014] Figure 2 This is an exploded view of the overall structure of the present invention;

[0015] Figure 3 This is a schematic diagram of the internal structure of the chip clamp of the present invention;

[0016] Figure 4 This is a simplified circuit schematic diagram of the present invention;

[0017] Figure 5 This is a diagram showing the change in aperture over time during the aperture enlargement process of the present invention;

[0018] Figure 6 For the drilling and enlarging process of SiN in this invention x Graph showing voltage changes across the chip;

[0019] Among them, 1-Liquid pool one, 2-Liquid pool two, 3-Liquid pool three, 4-Clamp, 5-Screw one, 6-Screw two, 7-DC voltage module, 8-Chip clamping plate, 9-Electrode, 10-Rubber gasket, 11-Standard nanopore chip, 12-Thin film chip to be processed. Implementation

[0020] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0021] Example 1: As Figure 1 and Figure 2 As shown, a simple apparatus and method for fabricating nanopores and enlarging pore size on a thin-film chip using a constant DC voltage is disclosed. The apparatus includes a liquid pool 1, a liquid pool 2, a liquid pool 3, a DC voltage module 7, a clamp 4, a screw 5, a screw 6, a rubber washer 10, and a chip clamping plate 8. The chip clamping plate 8 is mounted in the sliding grooves of liquid pools 1 and 2. Liquid pools 1, 2, and 3 are mounted in the placement grooves of the clamp 4. Screws 5 and 6 clamp liquid pools 1 and 2, and 2 and 3, respectively. The two output electrodes 9 of the DC voltage module 7 are respectively inserted into liquid pool 1 and liquid pool 3; wherein, liquid pool 1 is a rectangular block structure, liquid pool 2 is an inverted L-shaped block structure, and liquid pool 3 is an L-shaped block structure; the clamp 4 is a rectangular frame structure with a notch at the upper left end and a placement groove in the middle; the screw 5 is threaded horizontally through the left side of the clamp 4 and abuts the right side of liquid pool 1 against the left side of liquid pool 2 along the horizontal direction; the screw 6 is threaded vertically through the top of the clamp 4 and presses the protruding part of the right end of liquid pool 2 against the protruding part of the left end of liquid pool 3.

[0022] In this embodiment, silicone gaskets 10 are attached to the bottom of the right protruding part of liquid pool 2 and the top of the left protruding part of liquid pool 3, and the thin film chip to be processed is installed in the two silicone gaskets 10.

[0023] Example 2: As Figure 3As shown, silicone gaskets 10 are attached to opposite sides of the two chip clamps 8. The two silicone gaskets 10 contain standard nanopore chips 11 with a thickness of 200-400nm. Nanopore chips with different pore sizes have different resistances, and therefore different voltages are obtained in the circuit.

[0024] Example 3: As Figure 1 and Figure 4 As shown, the drilling process is as follows: The thin-film chip 12 to be processed is placed between the rubber gaskets 10 of liquid pool 2 and liquid pool 3. An electrolyte solution of a certain concentration is injected into liquid pool 1, liquid pool 2, and liquid pool 3. The sliding chip clamp 8 selects a standard nanopore chip 11 with a known pore size and connects it to the solution. The two output electrodes 9 of the DC voltage module 7 are respectively inserted into the solutions of liquid pool 1 and liquid pool 3. At this time, the two thin-film chips are equivalent to being connected in series in the circuit. After turning on the DC voltage module 7 for a certain period of time, the DC voltage module 7 is turned off, and a nanopore with a stable pore size can be obtained. In this embodiment, as shown... Figure 5 and Figure 6 As shown, the initial resistance of the thin-film chip 12 (without holes) is essentially infinite, and the initial voltage applied across the thin-film chip 12 is the output voltage of the DC voltage module 7. After time t1, the thin film breaks down, creating nanopores, and its resistance drops instantaneously. According to the voltage division principle of a series circuit, the standard nanopore chip 11 shares part of the voltage, and the voltage applied across the thin-film chip 12 (with holes) immediately decreases, entering the hole expansion stage. In the early stage of hole expansion, the pore size of the nanopores on the thin-film chip 12 changes rapidly. As the pore size gradually increases, the resistance in the circuit gradually decreases, the voltage it receives also gradually decreases, and the pore size expansion rate gradually slows down until after time t2, when the pore size remains essentially constant, and hole expansion is complete. For different thin-film chips, even if the initial breakdown pore size differs, the final pore size is essentially the same after hole expansion for time t2. Furthermore, standard nanopore chips with a length of 200–400 nm are relatively thick, so their pore size is less prone to change, resulting in high experimental repeatability.

[0025] It should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any combination or equivalent transformation made based on the above embodiments shall fall within the scope of protection of the present invention.

Claims

1. A simple method for aperture-controllable nanopore drilling and hole expansion on thin-film chip, characterized in that, The application relates to a pore-forming and hole-expanding device. 1) sequentially placing liquid pool one, liquid pool two and liquid pool three on the placing groove of a clamp, placing the to-be-processed film chip between the rubber gaskets of liquid pool two and liquid pool three, and clamping liquid pool two and liquid pool three by rotating screw two; placing the standard nanometer hole chip with different hole diameters in the chip clamp plate, placing the chip clamp plate in the sliding groove of liquid pool one and liquid pool two, and clamping liquid pool one by rotating screw one; 2) injecting electrolyte solution with a certain concentration into liquid pool one, liquid pool two and liquid pool three, sliding the chip clamp plate to select the standard nanometer hole chip to control the hole diameter of the processed nanometer hole, inserting the output electrode of the direct-current voltage module into the solution in liquid pool one and liquid pool three, outputting voltage, and performing pore forming; 3) after a period of time, the punching is completed, and as the processed hole diameter becomes larger, the voltage applied to the two ends of the to-be-processed nanometer hole chip is reduced; therefore, as the processing time elapses, the hole diameter of the manufactured nanometer hole gradually stabilizes and no longer expands. The pore-forming and hole-expanding device comprises liquid pool one, liquid pool two, liquid pool three, a direct-current voltage module, a clamp, screw one, screw two, rubber gaskets and a chip clamp plate, the chip clamp plate is clamped between liquid pool one and liquid pool two, the punching chip is arranged between liquid pool two and liquid pool three, liquid pool one, liquid pool two and liquid pool three are fixed on the clamp through screw, and liquid pool two is arranged between liquid pool one and liquid pool three; the direct-current voltage module outputs constant voltage; liquid pool one, liquid pool two and liquid pool three are fixed in the placing groove of the clamp through screw one and screw two, screw one fixes liquid pool one, liquid pool two and liquid pool three in the placing groove of the clamp in the horizontal direction, and screw two fixes liquid pool two and liquid pool three in the placing groove of the clamp in the vertical direction; the chip clamp plate is located in the sliding groove of liquid pool one and liquid pool two, and the standard nanometer hole chip with a known hole diameter is arranged in the chip clamp plate; the rubber gaskets are respectively arranged between the contact surfaces of liquid pool one, liquid pool two and liquid pool three.

2. A simple method for making and enlarging apertures in a thin-film chip with controllable aperture size according to claim 1, characterized in that, The chip clamp plate is clamped between liquid pool one and liquid pool two, and the standard nanometer hole chip with a thickness of 100-1000 nm is arranged in the two chip clamp plates.

3. A simple method for making and enlarging apertures in thin-film chip nanomembrane according to claim 1, characterized in that, The to-be-processed film chip with a thickness of 5-30 nm is arranged between liquid pool two and liquid pool three.

4. The method according to claim 1, wherein the method is characterized by: The output electrode of the direct-current voltage module is inserted into liquid pool one and liquid pool three to provide constant voltage.

5. A simple method of drilling and reaming a hole in a thin film chip with controllable aperture of the nano-hole according to claim 2, characterized in that, The film material of the standard nanometer hole chip and the to-be-processed chip is silicon nitride, silicon oxide, aluminum oxide or graphene.

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