Automatic exposure device for metal needle tip in preparation of nanofluid device

Abstract

The utility model provides an automatic exposure device for a metal needle tip in nanofluid device preparation, a sample carrying module comprises a supporting part, the supporting part is connected with a sample tray, the sample tray is provided with a plurality of through holes for placing sample carriers, and each through hole is provided with a channel serial number; the sample tray is driven by the first driver to rotate; the polishing work module comprises a polishing disc and a second driver, a grinding tool is arranged in the polishing disc, a conductive solution is contained in the polishing disc, and the polishing disc is driven by the second driver to rotate in the direction opposite to the sample tray; the sample carrier is internally provided with a metal needle tip sealed by an embedding material, and when the sample carrier is arranged in the through hole, the capillary glass tube sealing end of the metal needle tip is immersed into the conductive solution of the polishing disc and interferes with the grinding tool; and the circuit communication module transmits a serial number signal of the channel for placing the sample carrier and a polishing parameter signal of the metal needle tip in the channel to the control circuit so as to control the start and stop of the automatic exposure device.

Description

Technical Field

[0001] The utility model relates to the field of nano-fluid device automation equipment, and particularly relates to an automatic exposure device for metal tips in the preparation of nano-fluid devices. Background Technique

[0002] Bionic nano-fluid ionics is inspired by the mechanism of nerve signal generation and storage in the brain. By means of micro-nano technology in the field of nano-fluidics, the nano-confined space system is designed to realize the intelligent regulation of the fluid transport behavior of ions and the like inside it, with the expectation of reproducing the nerve electrical signals in the human brain on an artificial nano-fluid device platform. The successful preparation of artificial nano-fluid devices will have broad application prospects in future interdisciplinary fields such as artificial intelligence, brain-computer interface, and brain-like intelligence.

[0003] At present, in the preparation of nano-fluid devices, an important method is to obtain a sharpened nano-tip morphology structure of a metal wire based on electrochemical corrosion. Through the method of encapsulation with an embedding material, the sharpened nano-tip morphology structure of the metal wire is replicated into the product as a template, and then the metal tip is exposed by mechanical polishing. Finally, the template is removed by aqua regia, that is, the "Bench-Top" template method preparation method. Using this method, the preparation cost is low and the quality of the obtained product is relatively high, but there are still disadvantages such as cumbersome operation steps, large manual errors, low automation level, and inability to customize the nano-pore / channel size according to requirements.

[0004] A particularly important step in the "Bench-Top" template method: expose the top of the embedded metal tip so that a nano-pore / channel with both ends open can be formed after the tip template is dissolved. The traditional method is to manually hold the capillary glass tube embedded with the metal tip and polish the sealed end of the capillary glass tube on the sandpaper surface until the top of the metal tip is exposed. This method often has disadvantages such as relatively long time, complex operation, and unstable polishing effect, thus limiting the efficiency and accuracy of nano-pore / channel preparation. In particular, due to the difficulty of manual operation control, the metal tip is often prone to excessive polishing after exposure, resulting in the size of the final nano-pore / channel not meeting the design requirements and even deviating from the target range. Content of the Utility Model

[0005] The utility model provides an automatic exposure device for metal tips in the preparation of nano-fluid devices, which can automatically polish the metal tips in the preparation of nano-fluid devices to expose them to the embedding material, prevent excessive polishing, and improve the polishing efficiency.

[0006] To solve the above technical problems, the present utility model provides an automatic exposure device for metal tips in the preparation of nanofluid devices, including a sample loading module, a polishing working module, and a circuit communication module; the sample loading module includes a support component, the support component is connected with a sample tray, and a plurality of through holes are arranged on the sample tray for placing sample carriers, and each through hole is set with a channel serial number; the sample tray rotates under the drive of a first driver;

[0007] The polishing working module includes a polishing disc and a second driver, the polishing disc is arranged opposite to the sample tray, a grinding tool is arranged in the polishing disc and filled with a conductive solution, and the polishing disc rotates along the direction opposite to the sample tray under the drive of the second driver;

[0008] The sample carrier is filled with a metal tip sealed with an embedding material. When the sample carrier is placed in the through hole, the sealed end of the embedding material of the metal tip is immersed in the conductive solution of the polishing disc and interferes with the grinding tool;

[0009] The circuit communication module transmits the channel serial number signal of the placed sample carrier and the polishing parameter signal of the metal tip in the channel to a control circuit to control the start and stop of the automatic exposure device.

[0010] In some embodiments, the embedding material of the metal tip includes a micro-diameter tubular material made of glass or quartz or polymer material

[0011] In some embodiments, the sample carrier includes a through rod, and a first chuck and a second chuck are respectively arranged at both ends of the through rod.

[0012] In some embodiments, the clamping hole diameter of the first chuck is smaller than the clamping hole diameter of the second chuck.

[0013] In some embodiments, the sample carrier includes a through rod, the diameter of the upper part of the through rod is larger than that of the lower part, and the diameter of the upper part is larger than the diameter of the through hole.

[0014] In some embodiments, the support component includes a support rod vertically arranged with the main body housing, the end of the support rod is connected with a loading platform, the first driver is arranged below the loading platform, and the sample tray is connected with the loading platform through the first driver.

[0015] In some embodiments, at least two loading platforms are connected to the end of the support rod to arrange at least two sample trays.

[0016] In some of these embodiments, the circuit and communication module further includes an ESP8266 module for implementing WiFi communication between the automated exposure device and a remote device. The circuit communication module further includes a DC-DC power conversion circuit, a reset circuit, and a crystal oscillator circuit.

[0017] In some of these embodiments, it further includes a main body housing. The support member is disposed above the main body housing, the polishing disc is disposed on the upper surface of the main body housing, and the circuit communication module is disposed inside the main body housing.

[0018] In some of these embodiments, the upper surface of the main body housing further includes a human-machine interface for displaying the polishing parameters of the metal tip.

[0019] Compared with the prior art, the beneficial effects of the present utility model are as follows: by providing a polishing disc and a sample tray that rotate in opposite directions, when the metal tip is polished on the sample tray, the polishing speed increases, improving the polishing efficiency; at the same time, the circuit communication module transmits the polishing parameter signal of the metal tip to the control circuit, so as to control the start and stop of the device and avoid over-polishing of the metal tip. Description of the Drawings

[0020] Figure 1 It is a schematic structural diagram of an automated exposure device for a metal tip in the preparation of a nanofluidic device;

[0021] Figure 2 It is a cross-sectional view of an automated exposure device for a metal tip in the preparation of a nanofluidic device;

[0022] Figure 3 It is a front view of an automated exposure device for a metal tip in the preparation of a nanofluidic device;

[0023] Figure 4 It is a side view of an automated exposure device for a metal tip in the preparation of a nanofluidic device;

[0024] Figure 5 It is a top view of an automated exposure device for a metal tip in the preparation of a nanofluidic device;

[0025] Figure 6 It is a schematic structural diagram of an automated exposure device for a metal tip in the preparation of a nanofluidic device adapted to a sample carrier;

[0026] Figure 7 It is a working principle diagram of an automated exposure device for a metal tip in the preparation of a nanofluidic device.

[0027] Reference numerals: 1, support rod; 2, motor compartment; 3, sample tray; 4, sample carrier; 5, polishing disc; 6, upper cover of the main machine housing; 7, main machine housing; 8, serial port screen; 9, power button switch; 10, first driver; 11, second driver; 12, main control board; 13, power hole; 14, copper rod; 15, electric grinding chuck; 16, nut; 17, through rod; 18, capillary glass tube; 19, solder paste; 20, platinum wire tip. Detailed implementation manners

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0029] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", "top / bottom end", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0030] In the description of the present invention, it should be noted that, unless otherwise clearly defined and limited, the terms "installed", "provided with", "sheathed / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a wall-mounted connection, a detachable connection, or an integral connection, can be a mechanical connection, can be an electrical connection, can be directly connected, or can be indirectly connected through an intermediate medium, and can be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0031] Referring to Figures 1-7 , an automatic exposure device for metal tips in the preparation of nanofluidic devices is provided, including a sample loading module, a polishing working module, a circuit communication module, and a main machine housing;

[0032] Above the main body housing 7, a sample loading module is provided. Specifically, a support member is provided above the main body housing 7. The support member includes a support rod 1 which is vertically disposed on the main body housing, and a load platform is connected to the end of the support rod. A cylindrical motor chamber 2 is provided below the load platform. A 28-step motor driver is provided in the motor chamber 2 as the first driver 10. The sample tray 3 is connected to the load platform through the first driver 10. A plurality of through holes are provided on the sample tray 3 for placing the sample carrier 4, and each through hole is set with a channel number. The sample tray 3 rotates under the drive of the first driver 10. The sample tray 3 is composed of upper and lower parts, and the through holes on the outer surface are arranged in a ring. A signal connection circuit is provided inside the sample tray 3 and is communicated with the circuit communication module.

[0033] The polishing work module includes a polishing disc 5 and a second driver 11. The second driver 11 uses a 57-step motor driver. The polishing disc 5 is disposed opposite to the sample tray 3 and is provided on the outer surface of the upper cover 6 of the main body housing. Abrasives are provided in the polishing disc 5 and a conductive solution is filled. The polishing disc 5 rotates under the drive of the second driver 11, and the polishing disc 5 rotates in the opposite direction to the sample tray 3. The conductive solution is an appropriate amount of KCl solution or NaCl solution with a concentration of 20 mM, and the abrasive is polishing sandpaper. The polishing sandpaper is synchronously rotationally connected to the polishing disc 5. The polishing sandpaper is a concentric circle of the polishing disc 5 with a radius 1 mm smaller than that of the polishing disc 5. Different meshes of polishing sandpaper can be selected according to the preparation requirements of nanochannels with different pore diameters.

[0034] The sample carrier 4 is made of conductive aluminum alloy material and contains a platinum wire tip 20 sealed by an embedded material capillary glass tube 18. When the sample carrier 4 is placed in the through hole, the sealed end of the capillary glass tube 18 is immersed in the conductive solution of the polishing disc 5 and interferes with the abrasive to polish the capillary glass tube 18.

[0035] The circuit communication module includes a main control board 12. The main control board 12 includes an ADC detection circuit and a metal tip detection circuit. The ADC detection circuit detects the channel number where the sample carrier 4 is placed, and the metal tip detection circuit detects the polishing parameters of the platinum wire tip in the channel and transmits the detection results to the control circuit to control the start and stop of the automatic exposure device.

[0036] The platinum wire tip of the sample to be polished is made by soldering a tungsten wire or a copper rod to the platinum wire and then inserting the platinum wire end into a capillary glass tube. Therefore, the diameter of the capillary glass tube end is larger than that of the tungsten wire or copper rod end. In this embodiment, since the copper rod is easier to be soldered to the platinum wire than the tungsten wire and copper is cheaper, the copper rod 14 and the platinum wire are soldered with solder paste 19. In order to firmly hold the sample to be polished, in this embodiment, a sample carrier 4 dedicated to the sample is designed. Specifically, the sample carrier 4 includes a through rod 17, and first and second electric grinding chucks 15 are respectively arranged at both ends of the through rod 17. The diameter of the first electric grinding chuck is smaller than that of the second electric grinding chuck; the clamping hole diameter of the first electric grinding chuck is 0.8 mm, and the clamping hole diameter of the second electric grinding chuck is 1.5 mm. The one with a smaller clamping hole diameter is used to clamp the copper rod 14, and the one with a larger clamping hole diameter is used to clamp the capillary glass tube 18. External threads are provided at both ends of the through rod 17, and the two ends are respectively inserted into the electric grinding chucks 15. Finally, the through rod nut 16 realizes the connection and fixation of the sample and the through rod 17.

[0037] In order to fix the sample carrier 4 on the sample tray 3, in this embodiment, the diameter of the upper part of the through rod 17 is larger than that of the lower part, and the diameter of the upper part is larger than the perforation diameter. When the sample carrier 4 is placed into the sample tray 3 from top to bottom, the lower part with a smaller rod diameter can pass through the perforation on the sample tray 3, while the upper part with a larger diameter cannot pass through, thus fixing the sample carrier 4 on the sample tray 3. One end of the lower part of the rod body with a smaller diameter is inserted into the second electric grinding chuck with a larger clamping hole diameter, and one end of the upper part of the rod body with a larger diameter is inserted into the first electric grinding chuck with a smaller clamping hole diameter.

[0038] In order to further increase the number of metal tips that can be polished at one time, in this embodiment, at least two carriers are connected to the end of the support rod 1 to provide at least two sample trays 3. Therefore, the number of sample carriers 4 that can be placed at one time can be further increased, improving the polishing efficiency.

[0039] In this embodiment, a serial port screen 8 and a power button switch 9 are embedded in the front of the main machine housing 7. The serial port screen 8 includes an LCD display screen and a touch screen, and a human-machine interaction interface is carried on this hardware basis. The human-machine interaction interface includes the display of the channel position serial number for placing the sample to be polished, the display of the polishing time, the display of the start button, the display of the screen brightness, and the display of the one-key Internet access function, etc. A power hole 13 is provided on the back of the main machine housing 7 for connecting an external power supply.

[0040] Inside the main body housing 7, there is also a main control board 12, which further includes a core microcontroller, a DC-DC power conversion circuit, a driver control circuit, an ESP8266 module, a reset circuit, and a crystal oscillator circuit. After receiving the data sent by the serial port screen, the core microcontroller executes the steps of channel detection, polishing, and metal tip detection. The DC-DC power conversion circuit converts the 24V voltage to 5V through a DC-DC buck regulator ME3116, reducing energy loss and improving the overall energy efficiency of the system. The ESP8266 module is used to implement the wifi communication between the automated exposure device and remote devices. The reset circuit is used for quick recovery when a system program operation fails. The crystal oscillator clock circuit provides a clock signal for the entire microcontroller system to meet the clock required for each function.

[0041] The specific implementation method is as follows:

[0042] Place the sandpaper into the polishing disc 5 of this device and fix it with a circular fixator. Then pour an appropriate amount of KCl solution or NaCl solution with a concentration of 20 mM so that the sandpaper is fully immersed in the solution. Correctly load the sample to be polished into the sample carrier 4, and then place the sample carrier 4 into the perforation of the sample tray 3. Multiple samples can be placed in the sample tray 3 at the same time. Turn on the power of this device and connect the circuit. The core microcontroller detects the channel position where the sample to be polished is placed through the ADC detection circuit and sends a signal to the human-machine interface through the serial port, and the channel position of the sample to be polished is displayed in real time on the human-machine interface.

[0043] When the user presses the start button on the human-machine interface, after the microcontroller completes the channel detection, it sends signals to the first driver 10 and the second driver 11 simultaneously through the driver control circuit. The output shaft of the first driver 10 forms a synchronous rotation connection relationship with the sample tray 3, driving the sample tray 3 to rotate. The output shaft of the second driver 11 forms a synchronous rotation connection relationship with the polishing disc 5, driving the polishing disc 5 to perform rotational polishing work. The sample tray 3 and the polishing disc 5 rotate in opposite directions, causing the sample to move in a circular motion with the center point of the sandpaper radius as the center, improving the polishing speed and thus further enhancing the polishing efficiency.

[0044] The two parallel sample trays 3 of the sample carriers are respectively driven by the first drivers 10 connected to them and can work in parallel, increasing the number of samples polished at one time. When the metal tip detection circuit detects that the platinum wire tip of a certain channel is exposed, that channel automatically stops working. After taking out the polished sample, the remaining uncompleted channels continue to work until all channel tasks are completed.

[0045] The status display area of each channel of the human-machine interaction interface displays in real time the polishing time, electrical signal, and calculated diameter of the nano-platinum disk of the polished sample at the corresponding channel position. When the sample of the corresponding channel is polished, the timing of the status display area of this channel stops, and the icon changes from green to gray. At the same time, the screen brightness adjustment and one-key Internet access functions can be achieved through the buttons in the upper right corner of the human-machine interaction interface. In addition, the automated exposure device communicates with the host computer via WIFI, enabling real-time data transmission, remote control, and monitoring functions.

[0046] The working principle of the present invention is as follows: The tip of the platinum wire tip 20 embedded in the capillary glass tube 18 is exposed by mechanical polishing to obtain a nano-platinum disk electrode. The sample carrier 4 of the capillary glass tube sample embedding the platinum wire tip will continuously move downward automatically due to the action of gravity and the continuous wear and tear at the front end of the capillary glass tube 18. The glass at the tip of the platinum wire tip 20 will be continuously polished and ground off, so that the platinum wire is gradually exposed.

[0047] The polishing process is mainly affected by the roughness of the contact surface, polishing time, and pressure distribution. During the polishing process, the resistance of the system composed of the capillary glass tube glass embedding the sharpened platinum wire tip, the conductive solution, and the polishing sandpaper is called the polishing resistance. Before the tip is exposed, the resistance of the glass layer between the platinum wire tip and the polishing sandpaper is the main resistance, and this resistance is infinite, so the resistance of the solution can be ignored. After the tip is exposed, the diffusion resistance at the nano-disk - electrolyte interface becomes the main resistance, and it can be calculated using the following formula:

[0048] R = (4ka) -1

[0049] where k is the conductivity of the conductive solution, and a is the radius of the platinum disk. As Figure 6 shown, during this process, the polishing resistance will continuously change with the change of the platinum disk radius. Based on this principle, a metal tip detection circuit is designed to measure the change of the polishing resistance during the polishing process, and the control of the diameter of the platinum disk electrode during the polishing process can be achieved. When the platinum disk electrode reaches about 0.5 nm, its polishing resistance will drop from the order of 10^18 to the order of 10^9. Using this principle, a 500 MΩ reference resistor is placed between the gate and source of the NMOS transistor. When the polishing resistance drops to 1 GΩ, the NMOS transistor conducts, and the ADC detection signal changes from high level to low level.

[0050] The automated exposure device of this embodiment can polish multiple samples to be polished simultaneously in parallel, which can improve the polishing efficiency and the utilization rate of polishing materials, thereby improving the precision and efficiency of nanochannel preparation. At the same time, the device of this embodiment can quickly detect the exposure of the metal tip and stop the polishing action to avoid the influence brought by over-polishing. By controlling the polishing parameters and real-time monitoring, the device of this embodiment can effectively control the shape and size of the glass single hole / channel to ensure that the finally prepared channel meets the design requirements.

[0051] At the same time, the device transmits data in real time with the host computer through WIFI communication, so as to establish a database of the system and further obtain the key parameters of glass single hole / channel preparation. In addition, the device of this embodiment emphasizes its adapted sample carrier and its unique sample loading method, which can avoid damage and rupture of the capillary glass tube caused by other factors while keeping the sample carrier stable during the polishing process, playing an important protective role for the sample.

[0052] As mentioned above, only the specific preferred embodiment of the present utility model is described, but the design concept of the present utility model is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present utility model who makes non-substantive modifications to the present utility model using this concept shall fall within the scope of infringement of the protection of the present utility model.

Claims

1. An automated exposure device for metal needle tips in the preparation of nanofluidic devices, characterized in that: It includes a sample carrying module, a polishing working module, and a circuit communication module; the sample carrying module includes a supporting component, the supporting component is connected to a sample tray, a plurality of through holes are provided on the sample tray for placing a sample carrier, and each of the through holes is set with a channel number; the sample tray rotates under the driving of a first driver; The polishing working module comprises a polishing disc and a second driver, wherein the polishing disc is arranged opposite to the sample tray, wherein a grinding tool and a conductive solution are arranged in the polishing disc, and the polishing disc rotates in a direction opposite to the sample tray under the driving of the second driver; The sample carrier contains a metal needle tip sealed with an embedding material, and when the sample carrier is placed in the through hole, the embedding material sealed end of the metal needle tip is immersed in the conductive solution of the polishing disk and interferes with the abrasive tool; The circuit communication module transmits the channel number signal of the sample carrier and the polishing parameter signal of the metal needle tip in the channel to the control circuit to control the start and stop of the automatic exposure device.

2. The automatic exposure device for metal needle tips in the preparation of nanofluidic devices according to claim 1, characterized in that: The embedding material of the metal needle tip includes a micro-diameter tubular material made of glass, quartz or high molecular polymer material.

3. The automatic exposure device for metal needle tips in the preparation of nanofluidic devices according to claim 1, characterized in that: The sample carrier comprises a through rod, and two ends of the through rod are respectively provided with a first chuck and a second chuck.

4. The automatic exposure device for metal needle tips in the preparation of nanofluidic devices according to claim 3, characterized in that: The diameter of the clamping hole of the first clamping head is smaller than the diameter of the clamping hole of the second clamping head.

5. The automatic exposure device for metal needle tips in the preparation of nanofluidic devices according to claim 1, characterized in that: The sample carrier includes a through rod, an upper portion of the through rod having a diameter greater than a lower portion, and the upper portion diameter is greater than the through hole diameter.

6. The automatic exposure device for metal needle tips in the preparation of nanofluidic devices according to claim 1, characterized in that: The supporting component comprises a supporting rod vertically arranged with respect to the main body housing, the end of the supporting rod is connected with a stage, the first driver is arranged below the stage, and the sample tray is connected with the stage via the first driver.

7. The automatic exposure device for metal needle tips in the preparation of nanofluidic devices according to claim 6, characterized in that: At least two loading platforms are connected to the ends of the support rods so as to arrange at least two sample trays.

8. The automatic exposure device for metal needle tips in the preparation of nanofluidic devices according to claim 1, characterized in that: The circuit and communication module also includes an ESP8266 module for realizing WiFi communication between the automatic exposure device and the remote device. The circuit communication module also includes a DC-DC power conversion circuit, a reset circuit, and a crystal oscillator circuit.

9. The automatic exposure device for metal needle tips in the preparation of nanofluidic devices according to claim 1, characterized in that: It also includes a host shell, the support component is arranged above the host shell, the polishing plate is arranged on the upper surface of the host shell, and the circuit communication module is arranged inside the host shell.

10. The automatic exposure device for metal needle tips in the preparation of nanofluidic devices according to claim 9, characterized in that: The upper surface of the host shell also includes a human-computer interaction interface for displaying the polishing parameters of the metal needle tip.

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