A method for preparing a thumbtack micro-nano robot

Abstract

The present invention relates to the technical field of micro-nanorobot preparation, and more specifically, to a method for preparing a thumbtack micro-nanorobot. The method comprises the following steps: S1: obtaining a porous polycarbonate (PC) template; S2: using a magnetron sputtering deposition system to ionize argon gas and bombard a silver target with the ions under the action of an electric field, sputtering silver atoms onto the reverse side of the porous PC template; S3: attaching a double-conducting copper foil tape to one side of the porous PC template bearing silver, ensuring subsequent good electrical contact with the silver surface of the porous PC template; S4: obtaining a thumbtack micro-nanorobot using electrochemical deposition; S5: removing the template from the electrochemical deposition apparatus, rinsing the template surface with deionized water, and removing the electrolyte; S6: polishing the silver surface of the PC template with alumina slurry to remove the surface silver layer, and placing the template in a centrifuge tube; and S7: collecting the thumbtack micro-nanorobot by centrifugation. This method solves the problem of the single structure of tubular micro-nanorobots.

Description

Technical Field

[0001] The present invention relates to the technical field of micro-nano robot preparation, and in particular to a method for preparing a pushpin micro-nano robot. Background Art

[0002] Micro-nanorobotics have been a hot topic and research focus in international academic research in recent years, demonstrating great potential in fields such as environmental remediation, biomedical engineering, and cargo transportation. Micro-nanorobotics are robots operating at a scale between micrometers and nanometers, capable of converting external energy into mechanical energy for their own motion. They possess advantages such as small size, high thrust-to-weight ratio, good controllability, and robust scalability. Compared to micro-nanorobotics of other shapes, tubular micro-nanorobotics possess superior motion performance and a strong load capacity. However, current research on tubular micro-nanorobotics primarily focuses on modifying the outer or inner tubular layer, with limited research on external improvements. This has limited comparative analysis of tubular micro-nanorobotics of different morphologies. Therefore, a method for fabricating a "thumbnail" micro-nanorobotics is presented. This micro-nanorobotics incorporates a perforated base layer onto the tubular micro-nanorobotic structure, increasing the asymmetry of the tubular micro-nanorobotic structure and addressing the inherent structural monolithicity of tubular micro-nanorobotics. This method is of great significance for further research on tubular micro-nanorobotics. Summary of the Invention

[0003] In order to overcome the deficiencies of the prior art, the present invention provides a method for preparing a thumbtack micro-nano robot, which has the beneficial effect of solving the problem of the single structure of the tubular micro-nano robot.

[0004] A method for preparing a pushpin micro-nano robot comprises the following steps:

[0005] S1: Obtain a porous polycarbonate (PC) template;

[0006] S2: Using a magnetron sputtering deposition system, argon gas is ionized and the ions bombard a silver target under the action of an electric field, sputtering silver atoms onto the reverse side of the porous polycarbonate template;

[0007] S3: Adhere the double-conductor copper foil tape to one side of the porous polycarbonate template with silver to ensure good electrical contact with the silver surface of the porous polycarbonate template;

[0008] S4: Using electrochemical deposition to obtain thumbtack micro-nano robots;

[0009] S5: removing the template from the electrochemical deposition device, rinsing the template surface with deionized water to remove the electrolyte;

[0010] S6: Polish the silver surface of the polycarbonate template with alumina slurry to remove the surface silver layer, and place the template in a centrifuge tube;

[0011] S7: Add dichloromethane solution to the centrifuge tube to soak the template, and use an ultrasonic cleaner to allow the template and dichloromethane to fully react chemically to dissolve the polycarbonate. Place the centrifuge tube in a centrifuge at a speed of 6000 rpm for 3 minutes, collect the thumbtack micro-nano robot, and repeat the above operation 3 times;

[0012] S8: After washing the thumbtack micro-nano robot three times with ethanol and deionized water respectively, store it in deionized water at room temperature.

[0013] Furthermore, the electrochemical deposition adopts a three-electrode system, including a working electrode for depositing nickel and gold, a reference electrode for measuring the electrode potential, and a counter electrode for providing a polarization current loop. Silver chloride is used as the reference electrode, a platinum wire is used as the counter electrode, and a silver-surface porous polycarbonate template is used as the working electrode. Gold plating solution and nickel plating solution are used as electrolytes, respectively. The electroplating solution is composed of a main salt, a complexing agent, a buffer, etc., wherein the main salt of the gold plating solution is 0.04 mol / L tetrahydrate chloroauric acid, the complexing agent is 0.56 mol / L sodium sulfite, 0.26 mol / L potassium citrate, 0.14 mol / L ethylenediaminetetraacetic acid, the buffer is 10 mol / L sodium hydroxide, and the conductive salt is 0.81 mol / L potassium chloride.

[0014] Furthermore, when nickel is deposited first and then gold is deposited during the electrochemical deposition, the main body of the thumbtack is deposited first and is made of nickel, and the base part is deposited later and is made of gold. A two-step current method is used in the electrochemical nickel deposition process. In the first step, the current is -20 mA and the deposition time is 0.1 s. In the second step, the current is -6 mA and the deposition time is 1000 s. After the nickel deposition is completed, the porous polycarbonate template is rinsed with deionized water to remove the surface electrolyte and replace the new electrolyte with a gold plating solution. In the electrochemical gold deposition process, a constant current method is used to deposit gold, the cathode current is 4 mA, and the deposition time is 100 s, resulting in a thumbtack micro-nano robot with an outer tube diameter of 4.35±0.076 μm, a wall thickness of 1.64±0.121 μm, a tube length of 9.95±0.681 μm, a base diameter of 9.40±0.660 μm, and a base thickness of 2.91±0.624 μm.

[0015] Furthermore, by taking a new template and changing the deposition time or current intensity, a thumbtack micro-nano robot with controllable base size was prepared.

[0016] Furthermore, when the duration of electrochemical gold deposition was changed to 200 s while the other parameters remained unchanged, a thumbtack micro-nano robot with a base diameter of 9.88±0.379 μm and a base thickness of 2.75±0.065 μm was obtained.

[0017] Furthermore, when the duration of electrochemical gold deposition was changed to 50s while the other parameters remained unchanged, a thumbtack micro-nano robot with a base diameter of 7.23±0.335μm and a base thickness of 1.49±0.096μm was obtained.

[0018] Furthermore, the cathode current of electrochemically deposited gold was changed to 3 mA, and the other parameters remained unchanged, resulting in a thumbtack micro-nano robot with a base diameter of 8.98±1.066μm and a base thickness of 2.36±0.511μm.

[0019] Furthermore, the cathode current of electrochemically deposited gold was changed to 2 mA, while the other parameters remained unchanged, and a thumbtack micro-nano robot with a base diameter of 8.06±0.309 μm and a base thickness of 1.87±0.374 μm was obtained.

[0020] Furthermore, a new template was taken and the deposition order was changed, with gold deposited first and nickel deposited later, resulting in a thumbtack micro-nano robot with the main body made of nickel and gold and the base material containing a small amount of gold and a large amount of nickel. The base diameter was 8.84±0.958μm and the base thickness was 1.82±0.564μm.

[0021] Furthermore, the diameter of the porous polycarbonate template in S1 is 25 mm, and the pore diameter is 5 μm; and the sputtering thickness of silver atoms sputtered onto the reverse side of the porous polycarbonate template in S2 is 200 nm.

[0022] The present invention has the following beneficial effects:

[0023] 1. The present invention adopts a template-assisted electrodeposition method, which can produce a large number of thumbtack micro-nano robots without complex manufacturing requirements.

[0024] 2. The present invention utilizes electrochemical deposition to first deposit the metal that is easy to be the tubular body of the thumbtack, and then deposit the metal that is easy to be the base part of the thumbtack. By changing the deposition order, it is possible to prepare thumbtack micro-nano robots with different metals as the tubular body and the base body.

[0025] 3. The present invention utilizes electrochemical deposition to control the metal deposition rate and deposition thickness by controlling the deposition current intensity and deposition time, thereby being able to prepare a thumbtack micro-nano robot with a controllable base size. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention will be further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0027] Figure 1 Schematic diagram of the electrochemical deposition device;

[0028] Figure 2 SEM and EDS images of the thumbtack micro-nano robot;

[0029] Figure 3 SEM images of micro-nano robots with bases of different sizes under different deposition parameters;

[0030] In the figure: working electrode 1; reference electrode 2; counter electrode 3; reaction vessel base 4; sealing ring 5; reaction vessel 6; anode 7; electrochemical workstation 8; double-conducting copper foil tape 9. DETAILED DESCRIPTION

[0031] A method for preparing a pushpin micro-nano robot comprises the following steps:

[0032] S1: Obtain a porous polycarbonate (PC) template;

[0033] S2: Using a magnetron sputtering deposition system, argon gas is ionized and the ions bombard a silver target under the action of an electric field, sputtering silver atoms onto the reverse side of the porous polycarbonate template;

[0034] S3: Adhere the double-conductor copper foil tape to one side of the porous polycarbonate template with silver to ensure good electrical contact with the silver surface of the porous polycarbonate template;

[0035] S4: Using electrochemical deposition to obtain thumbtack micro-nano robots;

[0036] S5: removing the template from the electrochemical deposition device, rinsing the template surface with deionized water to remove the electrolyte;

[0037] S6: Polish the silver surface of the polycarbonate template with alumina slurry to remove the surface silver layer, and place the template in a centrifuge tube;

[0038] S7: Add dichloromethane solution to the centrifuge tube to soak the template, and use an ultrasonic cleaner to allow the template and dichloromethane to fully react chemically to dissolve the polycarbonate. Place the centrifuge tube in a centrifuge at a speed of 6000 rpm for 3 minutes, collect the thumbtack micro-nano robot, and repeat the above operation 3 times;

[0039] S8: After washing the thumbtack micro-nano robot three times with ethanol and deionized water respectively, store it in deionized water at room temperature.

[0040] The electrochemical deposition method uses an electrochemical deposition device, such as Figure 1As shown, the electrochemical deposition device includes a working electrode 1, a reference electrode 2, a counter electrode 3, a reaction vessel base 4, a sealing ring 5, a reaction vessel 6, an anode 7 and an electrochemical workstation 8, and a double-conducting copper foil tape 9. The working electrode 1 is arranged on the upper side of the double-conducting copper foil tape 9, and the double-conducting copper foil tape 9 is arranged on the upper side of the reaction vessel base 4. A sealing ring 5 is arranged between the working electrode 1 and the reaction vessel 6. The double-conducting copper foil tape 9 is connected to the electrochemical workstation 8 through the anode 7. The electrochemical workstation 8 is connected to the reference electrode 2 and the counter electrode 3. The reference electrode 2 and the counter electrode 3 extend into the reaction vessel 6. The electrochemical deposition adopts a three-electrode system, including depositing nickel and gold. The working electrode 1, the reference electrode 2 for measuring the electrode potential, and the counter electrode 3 for providing the polarization current loop are silver chloride 2 as the reference electrode, platinum wire as the counter electrode 3, and a silver-surfaced porous polycarbonate template as the working electrode 1. The gold plating solution and nickel plating solution are used as electrolytes respectively. The plating solution consists of a main salt, a complexing agent, and a buffer. The main salt of the gold plating solution is 0.04 mol / L tetrahydrate chloroauric acid, the complexing agent is 0.56 mol / L sodium sulfite, 0.26 mol / L potassium citrate, and 0.14 mol / L ethylenediaminetetraacetic acid. The buffer is 10 mol / L sodium hydroxide, and the conductive salt is 0.81 mol / L potassium chloride. After the addition of sodium sulfite, the main salt is mainly [Au(SO3)2] 3- Potassium citrate and EDTA have good chelating effect and can be formed on [Au(SO3)2] 3- Nearby, it is conducive to the precipitation of gold ions. When pH < 7, [Au(SO3)2] 3- Dissociation into Au + and SO3 2- , then Au + Deposition by disproportionation reaction, SO3 2- Decomposition generates SO2, which reduces the stability of the gold plating solution. Therefore, the pH value of the above solution is adjusted to 8-10 with 10 mol / L sodium hydroxide solution. 3- +2OH - →2Au↓+SO4 2- +H2O+3SO3 2- The nickel plating solution contains 1.6 mol / L nickel sulfamate tetrahydrate as the main salt and 0.32 mol / L boric acid as the pH buffer to enhance the electroplating effect. 0.08 mol / L nickel chloride hexahydrate is added to prevent anode passivation and increase the number of free ions in the solution to enhance conductivity.

[0041] When nickel is deposited first and then gold is deposited during the electrochemical deposition, the main body of the thumbtack is deposited first and is made of nickel. The base part is deposited later and is made of gold. A two-step current method is used in the electrochemical nickel deposition process. In the first step, the current is -20 mA and the deposition time is 0.1 s. In the second step, the current is -6 mA and the deposition time is 1000 s. After the nickel deposition is completed, the porous polycarbonate template is rinsed with deionized water to remove the surface electrolyte and replace it with a new electrolyte, which is a gold plating solution. In the electrochemical gold deposition process, a constant current method is used to deposit gold, the cathode current is 4 mA, and the deposition time is 100 s. A thumbtack micro-nano robot with an outer tube diameter of 4.35±0.076 μm, a wall thickness of 1.64±0.121 μm, a tube diameter length of 9.95±0.681 μm, a base diameter of 9.40±0.660 μm, and a base thickness of 2.91±0.624 μm is obtained.

[0042] By taking a new template and changing the deposition time or current intensity, a thumbtack micro-nano robot with controllable base size was prepared.

[0043] When the duration of electrochemical gold deposition was changed to 200s, while the other parameters remained unchanged, a thumbtack micro-nano robot with a base diameter of 9.88±0.379μm and a base thickness of 2.75±0.065μm was obtained.

[0044] When the duration of electrochemical gold deposition was changed to 50s, while the other parameters remained unchanged, a thumbtack micro-nano robot with a base diameter of 7.23±0.335μm and a base thickness of 1.49±0.096μm was obtained.

[0045] The cathode current of electrochemically deposited gold was changed to 3 mA, and the other parameters remained unchanged, resulting in a thumbtack micro-nano robot with a base diameter of 8.98±1.066μm and a base thickness of 2.36±0.511μm.

[0046] The cathode current of electrochemically deposited gold was changed to 2 mA, and the other parameters remained unchanged, resulting in a thumbtack micro-nano robot with a base diameter of 8.06±0.309μm and a base thickness of 1.87±0.374μm.

[0047] The new template was taken and the deposition order was changed, gold was deposited first and then nickel, resulting in a thumbtack micro-nano robot with the main body made of nickel and gold and the base material containing a small amount of gold and a large amount of nickel. The base diameter was 8.84±0.958μm and the base thickness was 1.82±0.564μm.

[0048] The diameter of the porous polycarbonate template in S1 is 25 mm, and the pore diameter is 5 μm; in S2, silver atoms are sputtered onto the back surface of the porous polycarbonate template to a sputtering thickness of 200 nm.

Claims

1. A method for preparing a thumbtack micro-nano robot, characterized in that: The following steps are involved: S1: Obtain a porous polycarbonate (PC) template; S2: Using a magnetron sputtering deposition system, argon gas is ionized and the ions bombard a silver target under the action of an electric field, sputtering silver atoms onto the reverse side of the porous polycarbonate template; S3: Adhere the double-conductor copper foil tape to one side of the porous polycarbonate template with silver to ensure good electrical contact with the silver surface of the porous polycarbonate template; S4: Using electrochemical deposition to obtain thumbtack micro-nano robots; S5: removing the template from the electrochemical deposition device, rinsing the template surface with deionized water to remove the electrolyte; S6: Polish the silver surface of the polycarbonate template with alumina slurry to remove the surface silver layer, and place the template in a centrifuge tube; S7: Add dichloromethane solution to the centrifuge tube to soak the template, and use an ultrasonic cleaner to allow the template and dichloromethane to fully react chemically to dissolve the polycarbonate. Place the centrifuge tube in a centrifuge at a speed of 6000 rpm for 3 minutes, collect the thumbtack micro-nano robot, and repeat the above operation 3 times; S8: After washing the thumbtack micro-nano robot with ethanol and deionized water three times respectively, the robot was stored in deionized water at room temperature. The electrochemical deposition adopts a three-electrode system, including a working electrode for depositing nickel and gold, a reference electrode for measuring the electrode potential, and a counter electrode for providing a polarization current loop, with silver chloride as the reference electrode, a platinum wire as the counter electrode, and a silver-surfaced porous polycarbonate template as the working electrode. A gold plating solution and a nickel plating solution are used as electrolytes, respectively. The electroplating solution is composed of a main salt, a complexing agent, a buffer, and a conductive salt. The main salt of the gold plating solution is 0.04 mol / L tetrahydrate chloroauric acid, the complexing agent is 0.56 mol / L sodium sulfite, 0.26 mol / L potassium citrate, and 0.14 mol / L ethylenediaminetetraacetic acid, the buffer is 10 mol / L sodium hydroxide, and the conductive salt is 0.81 mol / L potassium chloride. During the electrochemical deposition, nickel is deposited first and then gold is deposited. The main body of the thumbtack is deposited first and is made of nickel. The base part is deposited later and is made of gold. A two-step current method is used in the electrochemical nickel deposition process. In the first step, the current is -20 mA and the deposition time is 0.1 s. In the second step, the current is -6 mA and the deposition time is 1000 s. After the nickel deposition is completed, the porous polycarbonate template is rinsed with deionized water to remove the surface electrolyte and replace it with a new electrolyte, which is a gold plating solution. In the electrochemical gold deposition process, a constant current method is used to deposit gold, the cathode current is 4 mA, and the deposition time is 100 s. A thumbtack micro-nano robot with an outer tube diameter of 4.35±0.076 μm, a wall thickness of 1.64±0.121 μm, a tube length of 9.95±0.681 μm, a base diameter of 9.40±0.660 μm, and a base thickness of 2.91±0.624 μm is obtained. The diameter of the porous polycarbonate template in S1 is 25 mm, and the pore diameter is 5 μm; in S2, silver atoms are sputtered onto the back surface of the porous polycarbonate template to a sputtering thickness of 200 nm.

2. The method for preparing a pushpin micro-nano robot according to claim 1, characterized in that: When the duration of electrochemical gold deposition was changed to 200 s and the other parameters remained unchanged, a thumbtack micro-nanorobot with a base diameter of 9.88±0.379 μm and a base thickness of 2.75±0.065 μm was obtained.

3. The method for preparing a pushpin micro-nano robot according to claim 1, characterized in that: When the electrochemical gold deposition time was changed to 50 s and the other parameters remained unchanged, a thumbtack micro-nano robot with a base diameter of 7.23±0.335 μm and a base thickness of 1.49±0.096 μm was obtained.

4. The method for preparing a pushpin micro-nano robot according to claim 1, characterized in that: By changing the cathode current of electrochemically deposited gold to 3 mA and keeping the other parameters unchanged, a thumbtack micro-nano robot with a base diameter of 8.98±1.066μm and a base thickness of 2.36±0.511μm was obtained.

5. The method for preparing a pushpin micro-nano robot according to claim 1, characterized in that: By changing the cathode current of electrochemically deposited gold to 2 mA and keeping the other parameters unchanged, a thumbtack micro-nano robot with a base diameter of 8.06±0.309μm and a base thickness of 1.87±0.374μm was obtained.

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