Apparatus and method for drawing inorganic crystalline and amorphous materials using graphite heaters

Abstract

The invention provides a device and a method for drawing inorganic crystal and amorphous materials by using a graphite heater, and belongs to the technical field of nano materials. The technical problems in the drawing process of inorganic crystal materials and inorganic non-crystal materials are solved. Inorganic crystal materials and inorganic non-crystal materials are drawn by using a method different from a CO2 laser for the first time. The drawing process comprises the following steps: (1) designing a soft pulling force parameter, and additionally arranging an adjustable soft pulling force in a heating process, so that the shape and the size of a drawn product have a more flexible adjusting space; and (2) a drawing process control mechanism of one of'displacement ', 'heating time' and'speed 'is adopted, so that the requirements of preparing different micro-nano probes and ultramicro electrodes are met.

Description

Technical Field

[0001] The invention belongs to the technical field of nano materials, and in particular relates to a device and a method for drawing inorganic crystals and amorphous materials using a graphite heater. Background Art

[0002] Inorganic crystal materials have regular crystal structures, excellent optical transparency, high hardness and chemical stability, such as quartz, oxide crystals (zirconia, titanium dioxide, etc.), crystalline metals (gold, silver, copper, etc.). Inorganic crystal materials are widely used in many fields such as chemistry, energy, biology, lasers, etc. In the field of chemistry, inorganic crystal materials such as zirconium oxide (ZrO2) are often used as electrolyte materials for high-temperature solid oxide fuel cells (SOFCs) due to their high ionic conductivity and excellent chemical stability, which promotes electrochemical reactions in chemical processes. In the biological field, zinc oxide (ZnO) crystals are widely used in biosensors for the detection of biomolecules and enzyme activity due to their good biocompatibility and piezoelectric properties. They play an important role in medical diagnosis and environmental monitoring due to their high sensitivity and stability. In the field of lasers, inorganic crystal materials such as yttrium aluminum garnet (Nd), titanium sapphire (Ti), potassium titanyl phosphate (KTP) are widely used in solid-state lasers and ultrashort pulse lasers for the generation and modulation of laser beams. These materials also play an important role in laser cutting, laser medical treatment, and optical communications. Through these applications, inorganic crystal materials have played a key role in promoting scientific and technological progress.

[0003] Inorganic amorphous materials have amorphous structures, unique mechanical properties, and easy processing due to the lack of long-range ordered lattice arrangement. For example, glass, amorphous silicon, and amorphous oxides (amorphous aluminum oxide, amorphous titanium oxide). Inorganic crystalline materials and inorganic amorphous materials are widely used in the fields of chemistry, energy, biology, and laser crystals. In the energy field, amorphous silicon and amorphous oxides are used as anode materials in lithium-ion batteries, effectively alleviating the problem of volume expansion and improving the cycle life and battery capacity. In the biomedical field, diamond-like carbon (DLC) coatings are widely used in the manufacture of biomedical devices such as heart stents, artificial joints, and bone implants due to their good biocompatibility, corrosion resistance, and low friction.

[0004] Micro-nano probes and ultra-microelectrodes have a wide range of uses and have important application value in the fields of life sciences, energy sciences, and chemistry and chemical engineering. However, due to the high difficulty in preparation, easy loss, and difficulty in transportation, micro-nano probes and ultra-microelectrodes are difficult to meet the daily scientific research needs of laboratories.

[0005] By regulating the heating and drawing process through the drawing instrument, glass or quartz capillaries can be processed into micro-nano probes of different sizes and morphologies, and applied to a variety of scientific research scenarios. For example, in single-cell research, micro-nano probes can accurately detect and manipulate the chemical environment inside a single cell, and directly measure the pH value, ion concentration, membrane potential and other indicators in the cell; in micro-nano processing research, micro-nano probes can be used for nano-patterning processing, and nano-scale device structures can be prepared by electrochemical etching or electrodeposition for microelectronics and photonics; in morphology imaging and electrochemical activity measurement research, such as scanning electrochemical liquid cell microscopy (SECCM), electrolyte solution is injected into the micro-nano probe, and the "meniscus" droplets formed at the front end of the tube due to capillary action contact with the substrate to form a tiny electrochemical cell, which can be used for electrochemical measurement. In addition, by recording the descending distance of the probe during contact with the substrate, the morphology of the substrate surface can also be imaged. This micro-nano electrochemical cell not only greatly improves the spatial resolution and reduces the consumption of samples and reagents, but also enables precise control of the local electrochemical environment. Its compact design allows for fine electrochemical analysis of tiny sample areas, greatly improving the sensitivity and accuracy of the measurement. In addition, the micro-liquid cell can also facilitate the study of fast reaction kinetics, and is particularly suitable for high-precision preparation and measurement in the fields of nanomaterials, electrocatalysis and biosensors.

[0006] Another important application of micro-nano probes is the preparation of ultra-micro electrodes. Specifically, the micro-nano probe is used as an insulating template, and the conductive material is embedded in the micro-nano probe tube by methods such as electrodeposition, electrophoresis or high-temperature gas phase pyrolysis to prepare ultra-micro electrodes. This method is usually called the "bottom-up" method. Relatively speaking, the electrode preparation scheme that treats the glass / quartz insulating layer and the built-in conductive metal wire / carbon fiber by thermal packaging or synchronous stretching packaging is usually called the "top-down" method. This method mainly relies on equipment such as a drawing instrument. The prepared electrode tip often needs to be polished to obtain a regular conductive cross-section, which has many characteristics, including negligible ohmic drop, small double-layer capacitance and fast mass transfer rate. Compared with traditional large electrodes, ultra-micro electrodes are usually hemispherical diffusion fields due to their small size, and can reach steady-state current in a short time. They are very suitable for rapid electrochemical measurements and are used in a variety of scientific research scenarios. For example, in biosensor research, ultramicroelectrodes can be used as highly sensitive biosensors to detect biomarkers in blood, urine or other body fluids; in micro-nanofabrication research, ultramicroelectrodes can be used for microelectrodeposition to precisely deposit metals or other materials on the electrode surface to create tiny circuit components, sensors and microstructures. In electrochemical research, ultramicroelectrodes are used for electrochemical imaging techniques, such as scanning electrochemical microscopy (SECM), which can detect and analyze the electrochemical activity of materials at the microscopic scale.

[0007] In the above-mentioned preparation methods of micro-nano probes and ultra-microelectrodes, quartz capillaries are superior to glass capillaries in terms of strength, hardness, dielectric properties and chemical stability. Quartz can withstand extremely high temperatures, is not easy to soften or deform, and can match the melting points of different types of metal wires, while glass is easy to soften at high temperatures. The difference in softening temperature of different materials puts higher requirements on the heating temperature (stability and heating temperature range) of the puller.

[0008] The current drawing instruments on the market usually have specific requirements for sample materials, and lack a drawing method suitable for a variety of materials (such as glass, quartz, and crystalline metals that require high-temperature drawing). Glass drawing instruments usually use resistance wires or electric heating plates as heating elements, but these elements oxidize at high temperatures in the air, resulting in changes in resistance values, which makes the heating temperature unstable. Such shortcomings will affect the stability and reproducibility of the drawing process. In addition, the upper temperature limit of these elements is low, and quartz tubes cannot be drawn. The quartz drawing instrument uses a CO2 laser to heat and draw quartz capillaries. However, the output power of the CO2 laser is easily attenuated, affecting its drawing effect. In addition, the optical path system is complex, has high requirements for the use and transportation environment, is difficult to maintain and replace, and has great limitations. These problems limit the service life of the equipment and the stability of the drawing process. The existing ultramicroelectrode preparation method has a low degree of automation and a high entry difficulty. It takes a long time of practice to master the preparation technology. In addition, due to the influence of manual operation, its reproducibility cannot be guaranteed. More importantly, the existing methods have a low success rate in preparing small-sized and small-RG ratio ultramicroelectrodes and cannot meet the daily needs of laboratories.

[0009] The drawing process of micro-nano probes is generally the same: first, fix the glass or quartz capillary (rod); then, generate high temperature through the heater to soften the fixed capillary; finally, apply tension to break the softened capillary in the middle to both sides, and quickly cool it in air or inert atmosphere to prepare two micro-nano probes with symmetrical tips. Similarly, ultra-micro electrodes can be prepared by synchronously drawing metal wires built into glass or quartz capillaries. The puller using resistance wire (sheet) as a heating device can only draw materials such as glass with a low softening point because the upper limit of the working temperature is about 1400℃. The puller using CO2 laser as a heating device softens quartz and other traditional glasses by emitting a wavelength close to the resonance frequency of the SiO2 lattice. Frequent switching of wavelengths will cause the laser output power to attenuate easily, and there are defects such as high maintenance costs.

[0010] In general, most of the drawing instruments on the market are only suitable for glass materials, and only a few are compatible with quartz and glass. However, these instruments usually have the disadvantages of high maintenance costs, long repair cycles, and rapid performance degradation. Technical solutions that can simultaneously draw glass, quartz micro-nano probes, ultra-micro electrodes, metals that require high-temperature drawing, and inorganic crystalline materials are even more scarce. Therefore, there is an urgent need for a universal drawing instrument and a stable drawing method that can be applied to inorganic crystalline materials (quartz, crystalline metals that require high-temperature drawing, etc.) and inorganic amorphous materials (glass, etc.). Summary of the invention

[0011] In view of this, in order to solve the technical difficulties encountered in the drawing process of inorganic crystal materials (quartz, crystalline metals that need to be drawn at high temperature, etc.) and inorganic amorphous materials (glass, etc.), the present invention proposes a device and method for drawing inorganic crystal materials (quartz, crystalline metals that need to be drawn at high temperature, etc.) and inorganic amorphous materials (glass, etc.) using a graphite heater to prepare micro-nano probes and ultra-micro electrodes, providing an efficient, stable and reliable solution for the production of experimental equipment in the fields of chemistry, biology and so on.

[0012] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a device for drawing inorganic crystals and amorphous materials using a graphite heater, comprising a heating cabin unit, a sliding support unit, a water cooling unit, a chassis structure unit and an inert gas flow unit, wherein the heating cabin unit is installed on the main body platform in the chassis structure unit, and a water cooling unit and an inert gas flow unit are installed outside the heating cabin unit, wherein the inert gas flow unit is used to provide inert gas for the heating cabin unit, and the water cooling unit cools down the heating cabin unit, and sliding support units are installed on both sides of the heating cabin unit;

[0013] The heating chamber unit includes a heating chamber shell, two electrodes, a graphite ring heater, a thermocouple for monitoring the real-time temperature of the heating chamber, a thermocouple for monitoring the real-time temperature of the electrode, and a positive electrode and a negative electrode for applying current to the graphite ring heater. The graphite ring heater is installed in the heating chamber shell, and the two electrodes are respectively located on both sides of the graphite ring heater. The graphite ring heater is divided into a positive electrode and a negative electrode. The heating chamber shell is also equipped with a thermocouple for monitoring the real-time temperature of the heating chamber and a thermocouple for monitoring the real-time temperature of the electrode.

[0014] The inert gas flow unit includes an inert gas pipeline inlet, a drying chamber, a heating chamber inert gas air inlet and a heating chamber inert gas outlet. The inert gas pipeline inlet is connected to the drying chamber through a No. 1 air inlet pipeline, and then connected to the heating chamber inert gas air inlet through the heating chamber inert gas air inlet. The heating chamber outer shell is provided with a heating chamber inert gas outlet.

[0015] Furthermore, the sliding support unit includes pulling arms on both sides of the heating chamber, fixed pulleys for turning the wire, metal spring sheets for limiting the pulling arms, knobs for fixing the capillary rods, and six pulleys arranged above and below the pulling arms.

[0016] Furthermore, the chassis structure unit includes a main body, a touch screen, function buttons, a hole for placing an exhaust hose, a light shielding cover and heat dissipation holes. The touch screen and function buttons are provided on the main body panel, heat dissipation holes are provided on the side, and a light shielding cover is installed above the main body, and the light shielding cover is provided with a hole for placing the exhaust hose.

[0017] Furthermore, the water cooling unit includes a heating chamber water cooling heat exchanger, a water cooling pipe inlet, a water cooling pipe outlet, a water inlet pipe, a water outlet pipe and an electrode water cooling heat exchanger. The heating chamber water cooling heat exchanger is installed on the outside of the heating chamber shell, and the heating chamber water cooling heat exchanger is respectively connected to the water cooling pipe inlet and the water cooling pipe outlet. The electrode water cooling heat exchanger is installed outside the electrode, and the electrode water cooling heat exchanger is connected to the water inlet pipe and the water outlet pipe.

[0018] Furthermore, the water in the water cooling unit must be Wahaha purified water.

[0019] A method for drawing inorganic crystals and amorphous materials using the device for drawing inorganic crystals and amorphous materials using a graphite heater specifically comprises the following steps:

[0020] Step 1: Open the user program in the main interface, select the program number that meets the requirements and load it, exit the user program, enter the drawing interface, and install the sample capillary;

[0021] Step 2: If you use a user-defined program to draw, the specific steps are as follows:

[0022] 1. Turn on the water cooling unit, drawing instrument and inert gas flow unit, turn on the gas valve switch on the test interface, adjust the rotor flowmeter to keep the flow at the user-defined flow, open the light shielding cover, place the glass or quartz capillary in the capillary clamping groove of the pulling arm on one side, and pass it through the heating chamber along the clamping groove, press the metal spring sheets on the pulling arms on both sides to tighten the pulling arms on both sides, fix the capillary with the knob, and close the light shielding cover;

[0023] 2. Click "Heat Value Test" on the drawing interface to measure the actual softening heat value of sample tubes of different materials and sizes;

[0024] 3. According to the calorific value test results in step 2, enter the calorific value parameters. The user can adjust the calorific value, speed, delay time, tension and cycle parameters according to the required target pipe diameter and shape. Click "Load Program" on the drawing interface. After the screen displays "Load Successfully", click the "Start" button to start the drawing operation.

[0025] 4. After the drawing is completed, open the light shielding cover, loosen the knob, and remove the micro-nano probe;

[0026] 5. Program saving: Click "Save Program" to store the program interface parameters with a custom name and call it through "User Program";

[0027] 6. Instrument shutdown: turn off the inert gas, exit the drawing interface, open the test interface, select "open gas valve", release the residual pressure in the protective gas pipe, and turn off the power switch of the water cooling unit and the drawing instrument;

[0028] Step 3: If you use the user program to draw, the operation steps are as follows:

[0029] 1. Turn on the water cooling unit, drawing instrument and inert gas flow unit, adjust the rotor flowmeter to keep the flow rate at 1L / min, and fix the capillary according to step 1 in step 2;

[0030] 2. After entering the user program, load the appropriate program, return to the drawing interface, click the "Start" button to perform the drawing operation;

[0031] 3. After drawing is completed, all operations refer to steps 4 to 6 in step 2.

[0032] Furthermore, the drawing interface includes calorific value, tension 1, speed, displacement, heating time, delay time, tension 2 and cycle parameters, wherein the calorific value is set according to the result of the calorific value test, generally within ±30 of the calorific value test value, and the total range of the calorific value is 0-1000 after the safety mode is turned off; tension 1 is used to regulate the soft tension of the heating process; displacement, speed and heating time are the judgment conditions for stopping heating during the drawing process, and the above three parameters only support selective input of one of them: displacement is the movement amount of the pulling arm during the heating process, speed is the moving rate of the pulling arm during the heating process, and heating time is the duration of applying current; delay time is the interval time from the graphite ring heater (103) stopping to the application of tension; tension 2 is the force used for drawing after heating stops; cycle is the preset number of actions of each row of parameters, and a single row cycle is up to 10 times.

[0033] Furthermore, after the program settings are completed, click "Load Program" and press the start button. The instrument will automatically adjust each unit module according to the set parameters, start the timing function, and collect and feedback various monitoring data at high speed. First, the microcontroller controls the inert gas valve to open, so that the inert gas passes through the drying chamber into the heating chamber shell to ensure that the gas is dry. At a certain flow rate, the inert gas is continuously introduced for a certain time to stabilize the gas environment in the heating chamber, and then heating is started. During the drawing process, the inert gas will continue to be introduced into the heating chamber shell to maintain a flowing inert gas environment. The thermocouple that monitors the real-time temperature of the heating chamber and the thermocouple that monitors the real-time temperature of the electrode respectively monitor the temperature of the heating chamber and the electrode in real time. The displacement sensor will synchronously record the movement of the pulling arm. When the displacement, speed or heating time reaches the program setting value, the heater stops working. The instrument will apply tension after the delay time ends to complete the drawing and enter the cycle. The photoelectric converter will monitor in real time whether the capillary has been broken.

[0034] Furthermore, during the drawing process, the water cooling system operates continuously, and low-temperature water flows out of the water cooler, flows into the heating chamber water-cooled heat exchanger through the water cooling pipe, and continuously exchanges heat with the heating chamber shell, thereby ensuring rapid cooling in the chamber. The water passing through the heating chamber water-cooled heat exchanger then flows through the heating chamber water-cooled heat exchanger and finally returns to the water cooler, wherein the heating chamber water-cooled heat exchanger and the electrode are both connected by copper metal elements.

[0035] Furthermore, when the drawing program is finished, the inert gas valve will close automatically after a certain period of time. If the capillary is not broken after all programs are completed, the instrument will also terminate the drawing. Except for water cooling and inert gas circuit, the above parameters can be saved and called through the drawing interface. You can also choose the reference program provided by the system for the drawing process. In addition, the equipment is also equipped with stop and emergency stop buttons to ensure that the program or equipment operation can be quickly terminated in an emergency.

[0036] Compared with the prior art, the device and method for drawing inorganic crystals and amorphous materials using a graphite heater described in the present invention have the following beneficial effects:

[0037] (1) The ultra-high temperature heating technology of the present invention based on the Joule heat principle realizes a drawing process with high stability and high repeatability. The inert gas atmosphere avoids the oxidation reaction of the metal wire with the air under high temperature conditions when the heating element and the ultra-microelectrode are prepared. The flowing dry (through a drying chamber or other drying device) inert gas realizes the stable heating of the graphite heater, which is beneficial to the operating life of the heating element and the preparation of the ultra-microelectrode. The graphite ring in the heating chamber is protected by the inert gas, which greatly reduces the loss of the heating device in the air.

[0038] (2) At the same time, the present invention uses a desiccant module to dry the inert gas introduced into the heating chamber to prevent humidity changes from affecting the drawing process. The above two points ensure the stable operation of the graphite heater in the heating chamber.

[0039] (3) The present invention can be used to draw inorganic crystalline materials (quartz, crystalline metals that require high-temperature drawing, etc.) and inorganic non-crystalline materials (glass, etc.) to prepare micro-nanotubes and ultra-microelectrodes.

[0040] (4) The present invention adopts high-efficiency water cooling technology. Low-temperature water flows out of the water cooler and enters the water-cooled heat exchanger of the heating chamber to continuously exchange heat with the heating chamber, thereby ensuring rapid cooling of the chamber. The water passing through the water-cooled heat exchanger of the heating chamber then flows through the water-cooled electrode and finally returns to the water cooler. The water-cooled heat exchanger of the heating chamber and the electrode are both connected by copper metal elements. Copper is a good thermal conductor to achieve rapid cooling of the heating chamber and the graphite heater, greatly improving the drawing efficiency.

[0041] (5) The graphite ring heater in the present invention has low production cost, simple and convenient maintenance, low requirements for the operating environment, and the ordinary equipment maintenance process can be completed in the laboratory through simple operations.

[0042] (6) The present invention adds an adjustable "pulling force 1" during the heating process. This design makes up for the problem that the "soft pulling force" cannot be adjusted during the drawing process, thereby effectively solving the technical problem that different tip cone angles cannot be quickly adjusted using the same size heater.

[0043] (7) The design of the drawing procedure of the present invention, including the addition of the "soft pulling force" parameter and the selection of the drawing mechanism from among "displacement", "heating time" and "speed", not only meets the preparation requirements of different micro-nano probes and ultra-micro electrodes, but also allows for more flexible regulation of the morphology and size of the drawn products. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0045] Figure 1 It is the main interface of the drawing instrument of the present invention;

[0046] Figure 2 It is a schematic diagram of multiple control parameters of the drawing interface;

[0047] Figure 3 It is the user program interface of the drawing instrument;

[0048] Figure 4 It is the system setting interface of the drawing instrument;

[0049] Figure 5 It is the test interface of the drawing instrument;

[0050] Figure 6 It is the overall structural schematic diagram of the drawing instrument;

[0051] Figure 7 It is a top view of the internal structure of the drawing instrument;

[0052] Figure 8 This is a schematic diagram of the back pipeline of the drawing instrument;

[0053] Fig. 9 This is a front view of the heating chamber of the drawing apparatus;

[0054] Fig.10 It is the structural diagram of the electrode water-cooled heat exchanger;

[0055] Fig.11 It is a half-section diagram of the electrode water-cooled heat exchanger;

[0056] Fig.12 are photos of glass micro-nano probes of different sizes under an optical microscope, wherein a is a photo of a glass micro-nano probe with a diameter of 8 μm under an optical microscope, b is a photo of a glass micro-nano probe with a diameter of 5 μm under an optical microscope, c is a photo of a glass micro-nano probe with a diameter of 2 μm under an optical microscope, and d is a photo of a glass micro-nano probe with a diameter of 500 nm under an optical microscope;

[0057] Fig.13 are photos of quartz micro-nano probes of different sizes under an optical microscope, wherein a is a photo of a glass micro-nano probe with a diameter of 12 μm under an optical microscope, b is a photo of a glass micro-nano probe with a diameter of 4 μm under an optical microscope, c is a photo of a glass micro-nano probe with a diameter of 1 μm under an optical microscope, and d is a photo of a glass micro-nano probe with a diameter of 500 nm under an optical microscope;

[0058] Fig.14 a is a full-view photo of the gold ultramicroelectrode, b is a photo of the tip under an optical microscope, and c is a CV curve (scan rate 0.1 V / s, solution 1 mmol / L FcMeOH and 1 mol / L KCl(H2O));

[0059] Fig.15 a is a full-view photo of the platinum ultramicroelectrode, b is a photo of the tip under an optical microscope, and c is a CV curve (scan rate 0.1 V / s, solution 1 mmol / L FcMeOH and 1 mol / L KCl(H2O)). DETAILED DESCRIPTION

[0060] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely explain the technical solutions in the embodiments of the present invention. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict, and the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0061] See also Figure 1-15 The present embodiment is described as a device for drawing inorganic crystals and amorphous materials using a graphite heater, comprising a heating chamber unit 100, a sliding support unit 200, a water cooling unit 300, a chassis structure unit 400 and an inert gas flow unit 500. The heating chamber unit 100 is installed on a platform of a main body 401 in the chassis structure unit 400, and a water cooling unit 300 and an inert gas flow unit 500 are installed outside the heating chamber unit 100. The inert gas flow unit 500 is used to provide inert gas for the heating chamber unit 100, and the water cooling unit 300 cools down the heating chamber unit 100. Sliding support units 200 are installed on both sides of the heating chamber unit 100.

[0062] The heating chamber unit 100 includes a heating chamber shell 101, two electrodes 102, a graphite ring heater 103, a thermocouple 104 for monitoring the real-time temperature of the heating chamber, a thermocouple 105 for monitoring the real-time temperature of the electrode, a positive electrode 106 and a negative electrode 107 for applying current to the graphite ring heater, a graphite ring heater 103 is installed in the heating chamber shell 101, the two electrodes 102 are respectively located on both sides of the graphite ring heater 103, the graphite ring heater 103 is divided into a positive electrode 106 and a negative electrode 107, and a thermocouple 104 for monitoring the real-time temperature of the heating chamber and a thermocouple 105 for monitoring the real-time temperature of the electrode are also installed on the heating chamber shell 101. The heating chamber unit 100 heats and softens the capillary / rod through the graphite ring heater 103.

[0063] The sliding holding unit 200 includes pulling arms 201 on both sides of the heating chamber, fixed pulleys 202 for turning the wire, metal spring sheets 203 for limiting the pulling arms, knobs 204 for fixing the capillary rod, and six pulleys 205 arranged above and below the pulling arms. The sliding holding unit 200 is used to clamp the capillary / rod. During the drawing process, the capillary / rod moves on both sides of the unit to generate displacement, thereby achieving drawing.

[0064] The water cooling unit 300 includes a heating chamber water cooling heat exchanger 301, a water cooling pipe inlet 302, a water cooling pipe outlet 303, a water inlet pipe 304, a water outlet pipe 305 and an electrode water cooling heat exchanger 306. The heating chamber water cooling heat exchanger 301 is installed outside the heating chamber shell 101. The heating chamber water cooling heat exchanger 301 is connected to the water cooling pipe inlet 302 and the water cooling pipe outlet 303 respectively. The electrode 102 is installed with an electrode water cooling heat exchanger 306 outside. The electrode water cooling heat exchanger 306 is connected to the water inlet pipe 304 and the water outlet pipe 305. The water cooling unit 300 generates a lot of heat in the heating chamber due to the high heating temperature reached by the graphite ring heater 103. It is necessary to dissipate heat from the heating chamber through the water cooling unit 300 and dissipate heat from the electrode 102 at the same time.

[0065] The water in the water cooling unit 300 must be Wahaha purified water. The main reason is that the positive and negative poles 106, 107 of the graphite ring heater 103, the two heating chamber water-cooled heat exchangers 301 and the two electrodes 102 are all connected by copper metal elements. When the graphite heater 103 is in working state, the water flowing through the water-cooled electrodes will be under the voltage of the positive and negative poles. The use of Wahaha purified water can avoid the occurrence of water electrolysis reaction.

[0066] The chassis structure unit 400 includes a main body 401, a touch screen 402, function buttons 403, a hole 404 for placing an exhaust hose, a light shielding cover 405 and a heat dissipation hole 406. The touch screen 402 and function buttons 403 are arranged on the panel of the main body 401, and heat dissipation holes 406 are arranged on the side. A light shielding cover 405 is installed above the main body 401, and the light shielding cover 405 is provided with a hole 404 for placing an exhaust hose.

[0067] The inert gas flow unit 500 includes an inert gas pipeline inlet 501, air intake pipelines 502, 504, a drying chamber 503, a heating chamber inert gas inlet port 505 and a heating chamber inert gas outlet port 506. The inert gas pipeline inlet 501 is connected to the drying chamber 503 through the air intake pipeline 502, and then connected to the heating chamber inert gas inlet port 505 through the heating chamber inert gas inlet port 505. The heating chamber shell 101 is provided with a heating chamber inert gas outlet port 506.

[0068] The method for electrode drawing using the above device is as follows:

[0069] Step 1: Open the user program in the main interface, select the program number that meets the requirements and load it, exit the user program, enter the drawing interface, and install the sample capillary.

[0070] Step 2: If you use a user-defined program to draw, the typical operation steps are as follows:

[0071] 1. Turn on the water cooling unit 300, the drawing instrument and the inert gas flow unit 500, turn on the gas valve switch in the test interface, and adjust the rotor flowmeter to keep the flow rate at the user-defined flow rate (the recommended flow rate is 1L / min). Open the light shielding cover 105, place the glass or quartz capillary in the capillary clamping groove of the pulling arm 201 on one side, and pass through the heating chamber along the clamping groove, press the metal spring sheets 203 on the pulling walls 201 on both sides to tighten the pulling arms 201 on both sides, fix the capillary with the knob, and close the light shielding cover 105.

[0072] 2. Click "Heat Value Test" on the drawing interface to measure the actual softening heat value of sample tubes of different materials and sizes.

[0073] 3. Input the calorific value parameters according to the calorific value test results in step (2). Users can adjust the calorific value, speed (heating time, displacement), delay time, tension and cycle parameters according to the required target tube diameter and shape. Click "Load Program" on the drawing interface. After the screen displays "Load Successfully", click the "Start" button to start the drawing operation.

[0074] 4. After drawing is completed, open the light shielding cover 105, loosen the knob 204, and carefully remove the micro-nano probe.

[0075] 5. Program saving: Click “Save Program” to store the program interface parameters with a custom name and call it through “User Program”.

[0076] 6. Instrument shutdown: turn off the inert gas, exit the drawing interface, open the test interface, select "open gas valve", release the residual pressure in the protective gas pipe, and turn off the power switches of the water cooling unit 300 and the drawing instrument.

[0077] Step 3: If you use the user program to draw, the operation steps are as follows:

[0078] 1. Turn on the water cooling unit 300, the drawing apparatus and the inert gas flow unit 500, adjust the rotor flowmeter to keep the flow rate at 1 L / min, and fix the capillary according to step 2 (1).

[0079] 2. After entering the user program, load the appropriate program, return to the drawing interface, click the "Start" button to perform the drawing operation.

[0080] 3. After drawing is completed, all operations refer to step 2 (4)-(6).

[0081] Note: If you are drawing ultramicroelectrodes, you can use a glass / quartz capillary with a built-in metal wire (about 1-1.5 cm long). During the drawing process, you need to make sure that the metal wire passes through the heater and is symmetrical in the center, and connect a vacuum pump with the same power at both ends of the capillary to ensure that the metal wire remains straight in the tube.

[0082] The working principle of the present invention is:

[0083] The present invention controls modules such as a position control unit, an air valve and a heat dissipation unit, so that the drawing instrument automatically performs drawing according to various parameters preset in advance, including the working temperature of the heating device, the applied pulling force, the drawing displacement, the heating time, the drawing speed, and the inert gas.

[0084] Figure 1 The main interface of the drawing instrument is displayed, including the drawing interface, test interface, user program, system settings and instructions for use. The parameters of the drawing interface will be explained in detail next.

[0085] Figure 2 Multiple control parameters of the drawing interface are displayed in . Among them, the calorific value test refers to the measurement of the calorific value of the glass tube that melts naturally when no additional tension is applied. This value does not represent the actual temperature and is only used to quantify the relative unit heat; the calorific value is set according to the result of the calorific value test, generally within ±30 of the calorific value test value, and the total calorific value range is 0-1000 after the safety mode is turned off; tension 1 is used to regulate the soft tension of the heating process. This parameter mainly affects the change of the cone angle of the drawing result; displacement, speed and heating time are the judgment conditions for stopping heating during the drawing process. The above three parameters only support selective input of one of them: displacement is the movement amount of the pulling arm 201 during the heating process, speed is the moving rate of the pulling arm 201 during the heating process, and heating time is the duration of the applied current; delay time is the interval time from the heater stopping to the application of tension; tension 2 is the force used for drawing after heating stops; cycle is the preset number of actions of each row of parameters, and the maximum number of single-row cycles is 10.

[0086] After the program is set up, click "Load Program" and press the start button. The instrument will automatically adjust each unit module according to the set parameters, start the timing function, and collect and feedback various monitoring data at high speed. First, the microcontroller controls the inert gas valve to open, so that the inert gas passes through the drying chamber into the heating chamber to ensure that the gas is dry. According to a certain flow rate, the inert gas is continuously introduced for a certain time to stabilize the gas environment in the heating chamber, and then heating is started. During the drawing process, the inert gas will continue to flow into the heating chamber to maintain a flowing inert gas environment. The thermocouple monitors the temperature of the heating chamber and the heating clamp in real time, and the displacement sensor will synchronously record the movement of the pulling arm 201. When the displacement, speed or heating time reaches the program setting value, the heater stops working. The instrument will apply a pulling force after the delay time ends, complete the drawing and enter the cycle. The photoelectric converter will monitor in real time whether the capillary has been broken.

[0087] During the drawing process, the water cooling system is continuously operated, and low-temperature water flows out of the water cooler and flows into the heating chamber water-cooled heat exchanger 301 through the water cooling pipe, and continuously exchanges heat with the heating chamber shell 101, thereby ensuring rapid cooling in the chamber. The water passing through the heating chamber water-cooled heat exchanger 301 then flows through the heating chamber water-cooled heat exchanger 301 and finally returns to the water cooler, wherein the heating chamber water-cooled heat exchanger 301 and the electrode 102 are both connected by copper metal elements. The rapid cooling of the graphite heater is achieved by using copper as a good thermal conductor, which greatly improves the drawing efficiency.

[0088] When the drawing program is finished, the inert gas valve will close automatically after a certain period of time. If the capillary is still not broken after all programs are finished, the instrument will also terminate the drawing. Except for water cooling and inert gas circuit, the above parameters can be saved and called through the drawing interface, and the reference program provided by the system can also be selected for the drawing process. In addition, the equipment is also equipped with stop and emergency stop buttons to ensure that the program or equipment operation can be quickly terminated in an emergency.

[0089] In terms of drawing program design, a drawing process control mechanism with a choice of "displacement", "heating time" and "speed" was proposed for the first time. The introduction of the heating time parameter solves the problem of the lower limit of position controller detection. For example, the softening temperatures of silver wire and quartz capillary are quite different. If the softening temperature of quartz capillary is directly selected when encapsulating silver ultramicroelectrodes, encapsulation failure may occur. The correct operating steps should be: first select the melting point of the silver wire so that the silver wire fits tightly with the quartz capillary, and then heat the heater to the softening temperature of the quartz capillary for drawing. During the heating process, since the quartz capillary has not yet reached the softening temperature, the position control system cannot detect the tiny deformation, resulting in the failure of the displacement-based drawing mode. By setting the heating time, this problem can be avoided and the smooth progress of the drawing process can be ensured.

[0090] Figure 3 The figure shows the user program interface of the drawing instrument, which is used to store and call different drawing program parameters.

[0091] Figure 4 The system setting interface of the drawing instrument is shown in the figure. The temperature limit is used to set the upper limit of the heating temperature to protect the instrument. The heating times and drawing times are displayed since the instrument started running, recording the total number of heating and drawing times.

[0092] Figure 5 The test interface of the drawing instrument is shown in the figure, which is used to monitor the speed of the pulling arm 201 and the real-time temperature of the cabin and the clamp, and can debug the instrument's tension and calorific value parameters and control the gas valve switch.

[0093] Example 1: Drawing glass micro-nano probes of different sizes.

[0094] In this method, borosilicate glass capillaries (outer diameter 1 mm, inner diameter 0.7 mm) are used to prepare micro-nano probes. Fig.11 The images of glass micro-nano probes of different sizes under an optical microscope. The sizes and reference drawing parameters are 8μm (calorific value: reference calorific value test results; speed 10; delay time 0; tension 0; cycle 4-5 times), 5μm (calorific value: reference calorific value test results; speed 24; delay time 0; tension 0; cycle 3-4 times), 2μm (calorific value: reference calorific value test results; speed 32; delay time 5; tension 16; cycle 2-3 times), 500nm (calorific value: reference calorific value test results; speed 74; delay time 5; tension 58; cycle 2-3 times). The tips of the above micro-nano probes all have good geometric morphology.

[0095] Example 2: Pulling quartz micro-nano probes of different sizes.

[0096] This method uses a quartz capillary (outer diameter 1 mm, inner diameter 0.7 mm) to prepare a micro-nano probe. Fig.12 The images of quartz micro-nano probes of different sizes under an optical microscope. The sizes and reference pulling parameters are 12μm (calorific value: reference calorific value test results; speed 10; delay time 0; tension 0; cycle 5-6 times), 4μm (calorific value: reference calorific value test results; speed 30; delay time 5; tension 15; cycle 3-4 times), 1μm (calorific value: reference calorific value test results; speed 46; delay time 15; tension 62; cycle 2-3 times), 500nm (calorific value: reference calorific value test results; speed 87; delay time 15; tension 93; cycle 1-2 times). The tips of the above micro-nano probes all have good geometric morphology.

[0097] Example 3: Preparation of gold and platinum ultramicroelectrodes.

[0098] A glass capillary (outer diameter 1.5 mm, inner diameter 0.2 mm) with a gold wire or platinum wire with a diameter of 50 μm was drawn to prepare a gold or platinum ultramicroelectrode. The drawn electrode was polished by a polisher, graphite powder was poured into the electrode, and the graphite powder was compacted and inserted into the graphite powder using a conductive metal wire to form an electrical connection structure of gold wire or platinum wire-graphite powder-conductive metal wire, and the other end of the tube was sealed with epoxy resin to obtain an ultramicroelectrode.

[0099] Fig.13 and Fig.14 The image of gold and platinum ultramicroelectrodes under an optical microscope shows that the gold wire and platinum wire melt at high temperature and fit tightly with the glass capillary, effectively preventing leakage.

[0100] The size of the prepared ultramicroelectrode was tested. In an aqueous solution containing 1mmol / L ferrocene methanol (FcMeOH) and 1mol / L KCl, the ultramicroelectrode was used as the working electrode, Ag / AgCl (3mol / L KCl) was used as the reference electrode and the counter electrode, and a two-electrode system was used for cyclic voltammetry. According to the steady-state voltammetric formula of the disk ultramicroelectrode a=i / 4.64nFDc, the diameters of the polished gold and platinum ultramicroelectrodes were calculated to be 29μm and 32μm, respectively. Among them, n=1 is the number of electron transfers during FcMeOH oxidation, a is the radius of the ultramicroelectrode, i is the limiting diffusion current of the ultramicroelectrode, F is the Faraday constant (F=96485C / mol), and c=1×10 -3 mol / L is the concentration of FcMeOH, D = 7.6 × 10 -6 cm -2 / s is the diffusion coefficient of FcMeOH in water.

[0101] The reference parameters for the drawing process of the above experiment are as follows: the first line of program: calorific value: refer to the calorific value test result minus 30; heating time 10; delay time 0; tension 0; cycle 2-3 times; the second line of program: calorific value: refer to the calorific value test result; speed 10; delay time 0; tension 15; cycle 5-6 times.

[0102] The key points of the present invention are:

[0103] 1. For the first time, a method different from CO2 laser was used to draw inorganic crystalline materials (quartz tubes, crystalline metals that need to be drawn at high temperature, and quartz tubes with inserted metal wires, carbon fibers, etc.) and inorganic amorphous materials (glass tubes, glass tubes with inserted metal wires, carbon fibers, etc.), with a size range of 50nm to 20um.

[0104] The invention is intended to protect:

[0105] 1. The working environment of the graphite heater includes: (1) introducing inert gas to reduce the working loss of the graphite ring; (2) maintaining a flowing dry (passing through a drying chamber or other drying device) inert gas in the heating chamber to achieve stable heating of the graphite heater.

[0106] 2. A water cooling method, including: (1) design of a water-cooled electrode, (2) protection of the entire water cooling circulation system, and controlling the cooling rate of the heater through a water cooling device to achieve regulation of the shape of the micro-nano probe tip during the drawing process.

[0107] 3. Drawing procedure, including: (1) Design of "soft pulling force" parameters, adding adjustable "soft pulling force" during the heating process, so that the morphology and size of the drawn product have more flexible control space; (2) A drawing process control mechanism with three options of "displacement", "heating time" and "speed" to meet the needs of preparing different micro-nano probes and ultra-micro electrodes.

[0108] The embodiments of the present invention disclosed above are only used to help illustrate the present invention. The embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. According to the content of this specification, many modifications and changes can be made. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well.

Claims

1. A device for drawing inorganic crystals and amorphous materials using a graphite heater, characterized in that: The invention comprises a heating cabin unit (100), a sliding support unit (200), a water cooling unit (300), a chassis structure unit (400) and an inert gas flow unit (500); the heating cabin unit (100) is installed on a main body (401) platform in the chassis structure unit (400); the water cooling unit (300) and the inert gas flow unit (500) are installed outside the heating cabin unit (100); the inert gas flow unit (500) is used to provide inert gas for the heating cabin unit (100); the water cooling unit (300) is used to cool the heating cabin unit (100); and the sliding support units (200) are installed on both sides of the heating cabin unit (100); The heating chamber unit (100) comprises a heating chamber shell (101), two electrodes (102), a graphite ring heater (103), a thermocouple (104) for monitoring the real-time temperature of the heating chamber, a thermocouple (105) for monitoring the real-time temperature of the electrode, and a positive electrode (106) and a negative electrode (107) for applying current to the graphite ring heater. The graphite ring heater (103) is installed in the heating chamber shell (101). The two electrodes (102) are respectively located on both sides of the graphite ring heater (103). The graphite ring heater (103) is divided into a positive electrode (106) and a negative electrode (107). The heating chamber shell (101) is also equipped with a thermocouple (104) for monitoring the real-time temperature of the heating chamber and a thermocouple (105) for monitoring the real-time temperature of the electrode. The inert gas flow unit (500) comprises an inert gas pipeline inlet (501), a drying chamber (503), a heating chamber inert gas air inlet (505) and a heating chamber inert gas air outlet (506). The inert gas pipeline inlet (501) is connected to the drying chamber (503) via a No. 1 air inlet pipeline (502), and then connected to the heating chamber inert gas air inlet (505) via a heating chamber inert gas air inlet (505). The heating chamber shell (101) is provided with a heating chamber inert gas air outlet (506).

2. The device for drawing inorganic crystals and amorphous materials using a graphite heater according to claim 1, characterized in that: The sliding support unit (200) comprises pulling arms (201) on both sides of the heating chamber, fixed pulleys (202) for turning the wire, metal spring sheets (203) for limiting the pulling arms, a knob (204) for fixing the capillary rod, and six pulleys (205) arranged above and below the pulling arms.

3. The device for drawing inorganic crystals and amorphous materials using a graphite heater according to claim 1, characterized in that: The chassis structure unit (400) comprises a main body (401), a touch screen (402), a function button (403), a hole (404) for placing an exhaust hose, a light shielding cover (405) and a heat dissipation hole (406); the touch screen (402) and the function button (403) are arranged on the panel of the main body (401); the heat dissipation hole (406) is arranged on the side; a light shielding cover (405) is installed above the main body (401); and the light shielding cover (405) is provided with a hole (404) for placing an exhaust hose.

4. The device for pulling inorganic crystals and amorphous materials using a graphite heater according to claim 1, characterized in that: The water cooling unit (300) comprises a heating chamber water cooling heat exchanger (301), a water cooling pipe inlet (302), a water cooling pipe outlet (303), a water inlet pipe (304), a water outlet pipe (305) and an electrode water cooling heat exchanger (306); the heating chamber water cooling heat exchanger (301) is installed outside the heating chamber shell (101); the heating chamber water cooling heat exchanger (301) is respectively connected to the water cooling pipe inlet (302) and the water cooling pipe outlet (303); the electrode water cooling heat exchanger (306) is installed outside the electrode (102); the electrode water cooling heat exchanger (306) is connected to the water inlet pipe (304) and the water outlet pipe (305).

5. The device for pulling inorganic crystals and amorphous materials using a graphite heater according to claim 4, characterized in that: The water in the water cooling unit (300) must be Wahaha purified water.

6. A method for drawing inorganic crystals and amorphous materials using the device for drawing inorganic crystals and amorphous materials using a graphite heater as described in any one of claims 1 to 5, characterized in that: The specific steps include: Step 1: Open the user program in the main interface, select the program number that meets the requirements and load it, exit the user program, enter the drawing interface, and install the sample capillary; Step 2: If you use a user-defined program to draw, the specific steps are as follows:

1. Turn on the water cooling unit (300), the drawing instrument and the inert gas flow unit (500), turn on the gas valve switch on the test interface, adjust the rotor flowmeter to keep the flow rate at the user-defined flow rate, open the light shielding cover (405), place the glass or quartz capillary in the capillary clamping groove of the pulling arm (201) on one side, and pass through the heating chamber along the clamping groove, press the metal spring sheets (203) on the pulling arms (201) on both sides to tighten the pulling arms (201) on both sides, fix the capillary with a knob, and close the light shielding cover (405); 2. Click "Heat Value Test" on the drawing interface to measure the actual softening heat value of sample tubes of different materials and sizes; 3. According to the calorific value test results in step 2, enter the calorific value parameters. The user can adjust the calorific value, speed, delay time, tension 1, tension 2 and cycle parameters according to the required target tube diameter and shape. Click "Load Program" on the drawing interface. After the screen displays "Load Successfully", click the "Start" button to start the drawing operation.

4. After the drawing is completed, open the light shielding cover (405), loosen the knob (204), and remove the micro-nano probe; 5. Program saving: Click "Save Program" to store the program interface parameters with a custom name and call it through "User Program"; 6. Instrument shutdown: turn off the inert gas, exit the drawing interface, open the test interface, select "open gas valve", release the residual pressure in the protective gas pipe, and turn off the power switch of the water cooling unit (300) and the drawing instrument; Step 3: If you use the user program to draw, the operation steps are as follows:

1. Turn on the water cooling unit (300), the drawing instrument and the inert gas flow unit (500), adjust the rotor flowmeter to keep the flow rate at 1L / min, and fix the capillary according to step 1 in step 2; 2. After entering the user program, load the appropriate program, return to the drawing interface, click the "Start" button to perform the drawing operation; 3. After drawing is completed, all operations refer to steps 4 to 6 in step 2.

7. The method for pulling inorganic crystals and amorphous materials using a graphite heater according to claim 6, characterized in that: The drawing interface includes calorific value, tension 1, speed, displacement, heating time, delay time, tension 2 and cycle parameters, wherein the calorific value is set according to the result of the calorific value test, generally within ±30 of the calorific value test value, and the total range of the calorific value is 0-1000 after the safety mode is turned off; tension 1 is used to regulate the soft tension of the heating process; displacement, speed and heating time are the judgment conditions for stopping heating during the drawing process, and the above three parameters only support selective input of one of them: displacement is the movement amount of the pulling arm (201) during the heating process, speed is the moving rate of the pulling arm (201) during the heating process, and heating time is the duration of applying current; delay time is the interval time from the graphite ring heater (103) stopping to the application of tension; tension 2 is the force used for drawing after heating stops; cycle is the preset number of actions of each row of parameters, and a single row cycle is up to 10 times.

8. The method for pulling inorganic crystals and amorphous materials using a graphite heater according to claim 6, characterized in that: After the program setting is completed, click "Load Program" and press the start button. The instrument will automatically adjust each unit module according to the set parameters, start the timing function, and collect and feedback various monitoring data at high speed. First, the single-chip microcomputer controls the inert gas valve to open, so that the inert gas passes through the drying chamber into the heating chamber shell (101) to ensure that the gas is dry. According to a certain flow rate, the inert gas is continuously introduced for a certain time to stabilize the gas environment in the heating chamber, and then heating is started. During the drawing process, the inert gas will continue to be introduced into the heating chamber shell (101) to maintain the flowing inert gas environment. The thermocouple (104) that monitors the real-time temperature of the heating chamber and the thermocouple (105) that monitors the real-time temperature of the electrode respectively monitor the temperature of the heating chamber and the electrode (102) in real time. The displacement sensor will synchronously record the movement of the pulling arm (201). When the displacement, speed or heating time reaches the program setting value, the heater stops working. The instrument will apply a pulling force after the delay time ends to complete the drawing and enter the cycle. The photoelectric converter will monitor in real time whether the capillary has been broken.

9. The method for pulling inorganic crystals and amorphous materials using a graphite heater according to claim 6, characterized in that: During the drawing process, the water cooling system operates continuously, and low-temperature water flows out of the water cooler and flows into the heating chamber water-cooled heat exchanger (301) through the water cooling pipe, and continuously exchanges heat with the heating chamber shell (101), thereby ensuring rapid cooling in the chamber. The water passing through the heating chamber water-cooled heat exchanger (301) then flows through the heating chamber water-cooled heat exchanger 301 and finally returns to the water cooler, wherein the heating chamber water-cooled heat exchanger 301 and the electrode 102 are both connected by copper metal elements.

10. The drawing method of the device for drawing inorganic crystals and amorphous materials using a graphite heater according to claim 9: when the drawing program is completed, the inert gas valve will close automatically after a certain period of time. If the capillary is not broken after all programs are completed, the instrument will also terminate the drawing. Except for water cooling and inert gas circuits, the above parameters can be saved and called through the drawing interface, and the reference program provided by the system can also be selected for the drawing process. In addition, the equipment is also equipped with stop and emergency stop buttons to ensure that the program or equipment operation can be quickly terminated in an emergency.

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