Flexible positioning transfer rod suitable for low-dimensional material transfer and transfer method

Abstract

The invention discloses a flexible positioning transfer rod and a transfer method suitable for low-dimensional material transfer, a heating resistor is embedded in the transfer rod, and the end face, used for picking up a target sample material, of the front end of the transfer rod is of a synaptic array microstructure; wherein the heating resistor is used for electrifying and heating the synaptic array microstructure and heating and evaporating a solution at a target sample material; dripping a two-dimensional material target sample turbid liquid on the suspended structure of the test structure; picking up a low-dimensional material target sample from the turbid liquid under a microscope by using a flexible positioning transfer rod, and pulling and transferring the target sample to a suspended structure; by conducting the heating resistor, after the synaptic array microstructure is heated to volatilize the solution, the target sample naturally falls to the target position of the suspended structure, and the transfer process is completed. According to the method, the low-dimensional material target sample is transferred without pollution and with low mechanical damage, and the method is simple, easy to implement and high in repeatability.

Description

Technical Field

[0001] This invention relates to a transfer tool and method for low-dimensional materials, and more particularly to a material transfer tool and method applicable to the field of low-dimensional material characterization. Background Technology

[0002] As chip integration increases and individual devices shrink, the feature size of a single transistor's core structural unit has now exceeded 10 nanometers. On the other hand, with the development of wearable and portable devices, the operating environment of materials and devices is becoming increasingly complex. Alternating temperatures, bending, and light exposure all place more stringent demands on materials and devices. Therefore, it is crucial to study the structure-property relationship between material microstructure and device performance, and to conduct in-situ studies of the structural and performance evolution of low-dimensional semiconductor materials under multi-physics coupling.

[0003] Low-dimensional materials, due to their confined size, possess unique electrical, optical, and mechanical properties, attracting widespread research interest in multifunctional micro / nano devices. However, multiphysics loading, especially mechanical loading, is challenging for low-dimensional materials. One of the most commonly used methods is nanoindentation based on atomic force microscopy (AFM), which involves applying adjustable forces to a suspended sample on a microcantilever to deform it. However, because the test load is concentrated around the tip of the indenter, localized stress concentration occurs on the sample, posing a high risk of damage and severely impacting the accuracy of material parameter measurements. More importantly, accurately applying heat or light in situ within an AFM device is extremely difficult, representing one of the core bottlenecks hindering the exploration of multiphysics coupling, manipulation, and analysis.

[0004] Meanwhile, existing transfer methods for in-situ testing and characterization supporting the study of the evolution of low-dimensional material properties suffer from one or more of the following drawbacks: 1) The transfer process easily causes mechanical damage to the micro-cantilever structure or sample; 2) The transfer process introduces impurities, which is not conducive to studying the intrinsic properties of the sample; 3) Since the test sample is generally in the micro-nano size, it is impossible to accurately transfer it to the target location. In particular, two-dimensional materials are limited by atomic-level thickness, making it even more difficult to transfer them smoothly to a suspended target substrate. Therefore, achieving a high success rate in transfer is one of the difficulties hindering the development of in-situ testing technology for low-dimensional materials. Summary of the Invention

[0005] Purpose of the invention: In view of the above-mentioned prior art, a method for transferring low-dimensional materials to test suspended structures without pollution and with low mechanical damage is proposed, thereby reducing the difficulty of in-situ testing and characterization of low-dimensional materials.

[0006] Technical solution: A flexible positioning transfer rod suitable for low-dimensional material transfer, comprising: a heating resistor embedded inside the transfer rod, and the end face of the transfer rod for picking up the target sample material is a synaptic array microstructure; wherein, the heating resistor is used to energize and heat the synaptic array microstructure to achieve heating and evaporation of the solution in which the target sample material is located.

[0007] Furthermore, the material of the synaptic array microstructure is a polymer material with a viscous critical temperature and elasticity.

[0008] Furthermore, the polymer material is PDMS or silicone.

[0009] Furthermore, the main body of the transfer rod is a cuboid structure with a height of 0.05~0.1 mm and a cross-section of a rectangle with a length of 0.5~1 mm and a width of 0.1~0.5 mm; the synaptic array microstructure includes several cuboid synaptic units arranged at intervals, each cuboid synaptic unit having dimensions of 0.05~0.1 mm in length, 0.1~0.5 mm in width, and 0.05~0.1 mm in height, with the interval between the synaptic units being 0.05~0.1 mm.

[0010] Furthermore, the heating resistor is a serpentine heating resistor with a diameter of 0.05~0.1 mm and made of nickel-chromium alloy or copper-nickel alloy.

[0011] Furthermore, the process includes: dripping a suspension of the low-dimensional material target sample onto the suspended structure of the test structure; using a flexible positioning and transfer rod under a microscope to pick up the low-dimensional material target sample from the suspension and guide it to the target position on the suspended structure; by turning on a heating resistor, after the synaptic array microstructure is heated and the solution evaporates, the target sample naturally falls to the target position, and the target sample directly contacts the suspended structure of the test structure, thus completing the transfer of the target sample.

[0012] Furthermore, the suspension is an aqueous suspension or an ethanol solution containing low-dimensional materials.

[0013] Furthermore, the test structure is securely attached to a flat substrate with tape around its perimeter; the flat substrate is a silicon, quartz, or sapphire substrate.

[0014] Furthermore, the test structure is an in-situ thermal test chip or an in-situ mechanical test chip.

[0015] Furthermore, the heating resistor is energized and the heating temperature is controlled to be 60~200 ℃.

[0016] Beneficial effects: 1. This invention innovatively designs a flexible positioning and transfer rod with an embedded heating resistor. The heating resistor directly heats the target sample adhered to the synaptic array microstructure of the transfer rod, achieving direct positioning and heating of the transferred sample and completing solution evaporation. Compared to existing technologies, the flexible positioning and transfer rod solution proposed in this invention significantly shortens the heat conduction path for heating the target sample, which is beneficial for the effectiveness and precision of sample material heating control, and also enhances operational convenience and reduces power consumption.

[0017] 2. This method uses PDMS, a flexible polymer with a viscosity critical temperature, to prepare a flexible positioning and transfer rod. A synaptic array microstructure is designed at the front end. By controlling the heating temperature of the heating resistor, the synaptic array microstructure reduces the contact area between the target sample material and the front end of the flexible positioning and transfer rod during the separation process. This reduces the contact force on the contact surface, which helps to separate the sample from the contact surface of the flexible positioning and transfer rod, and effectively reduces mechanical damage to the target sample.

[0018] 3. The use of aqueous or ethanol solutions to prepare materials solves the problem of impurities introduced by organic solvents in existing transfer methods, reducing sample contamination and damage to the test structure during the transfer process; the use of flexible positioning transfer rods to pick up target samples solves the problem of mechanical damage caused by rigid probes in existing transfer methods. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a flexible positioning and transfer rod and a transfer method applicable to two-dimensional material transfer in an embodiment of the present invention; Figure 2 This is a scanning electron microscope image of the two-dimensional lead iodide material on the test structure in an embodiment of the present invention; Figure 3 Optical photographs for comparison of this invention; The figure is labeled as follows: 1. Transfer rod; 1-1. Synaptic array microstructure; 1-2. Cuboid structure; 1-3. Heating resistor; 2. Flat substrate; 3. Test structure; 3-1. Suspended structure; 4. Adhesive tape; 5. Suspension; 5-1. Two-dimensional material. Detailed Implementation

[0020] The invention will now be further explained with reference to the accompanying drawings. Example

[0021] A flexible positioning and transfer rod suitable for low-dimensional material transfer, such as Figure 1As shown, the main body of the flexible positioning and transfer rod is a cuboid structure 1-2. Two nickel-chromium alloy serpentine heating resistors 1-3 are installed inside the cuboid structure 1-2. The front end of the cuboid structure 1-2 has a synaptic array microstructure 1-1. The synaptic array microstructure 1-1 consists of five cuboid synapses arranged at intervals. One end of the serpentine heating resistor 1-3 is close to the synaptic array microstructure 1-1, and the other end is connected to an external power source.

[0022] The dimensions of the cuboid structure 1-2 of the main body of the flexible positioning and transfer rod are: length 0.5 mm, width 0.1 mm, and height 2 mm; the diameter of the serpentine heating resistor 1-3 is 0.05 mm; the dimensions of the cuboid synapse are: length 0.05 mm, width 0.1 mm, and height 0.05 mm, and the interval between adjacent synaptic units is 0.05 mm.

[0023] The method for making the flexible positioning and transfer rod is as follows: First, a mold with a cuboid structure 1-2 having a synaptic array microstructure 1-1 is made, and a serpentine heating resistor 1-3 is placed in the mold. PDMS polydimethylsiloxane solution is poured into the mold, and after it solidifies, it is demolded to form the flexible positioning and transfer rod 1.

[0024] A method for transferring low-dimensional materials based on a flexible positioning transfer rod is proposed. First, a clean, 10mm * 10mm flat SiO2 or Si substrate 2 is prepared. A test structure 3 with a suspended structure 3-1 is securely attached to the flat substrate 2 using tape 4. A suspension 5 containing lead iodide two-dimensional material 5-1 (1 mg / ml water solution) is dropped onto the surface of the suspended structure 3-1. Then, the target sample is picked up under a microscope using a flexible positioning transfer rod 1 and transferred to the target position on the suspended structure 3-1. The serpentine heating resistor 1-3 is energized and heated to 120℃. After the synaptic array microstructure 1-1 is heated and the solution evaporates, the target sample naturally falls to the target position. Figure 2 As shown, the transfer of the two-dimensional lead iodide material on test structure 3 is completed.

[0025] The preparation process of this invention is simple, with high repeatability and reliability. By combining the advantages of wet transfer, dry transfer, and probe transfer, it achieves non-destructive and efficient low-dimensional material transfer on test structures with suspended structures.

[0026] Comparative Example 1: A standard PDMS square structure with dimensions of 0.5 mm in length, 0.5 mm in width, and 3 mm in height was attached to a glass slide. Two-dimensional lead iodide material was prepared on the end planes of the PDMS square structure on the glass slide using mechanical peeling or solution method. The PDMS square structure was placed above a transfer platform, and the test structure 3 with the suspended structure 3-1 was placed on the transfer platform. The end of the PDMS square structure was brought into contact with the test structure 3, and the heating temperature was set to 120 ℃ for 2 min, and maintained at 120 ℃ for 1 min. Then, the PDMS square structure was slowly lifted, and it was found that there was no complete sample on the suspended structure 3-1. Figure 3 As shown in (a).

[0027] Conclusion: Because test structure 3 has a suspended structure, the two-dimensional material on the PDMS square structure is not uniformly heated and stressed during the transfer of the sample in Comparative Example 1, so the transfer of the complete sample cannot be achieved.

[0028] Comparative Example 2: On a 10 mm * 10 mm SiO2 / Si flat substrate 2, the test structure 3 was firmly attached with tape 4. Then, 10 μl of a suspension 5 containing lead iodide two-dimensional material 5-1 (1 mg / ml water solution) was dropped onto the pretreated suspended structure 3-1. The suspended structure 3-1 containing the lead iodide two-dimensional material 5-1 on the SiO2 / Si flat substrate 2 was heated to 120 ℃. After the solution evaporated, the target sample fell naturally. It was found that there was no ideal sample at the target location. Figure 3 As shown in (b).

[0029] Conclusion: In Comparative Example 2, because the liquid is amorphous and its direction is not fixed after the solution evaporates, precise transfer of the sample cannot be achieved.

[0030] Comparative Example 3: On a 10 mm * 10 mm SiO2 / Si flat substrate 2, the test structure 3 is firmly attached with tape 4, and then 10 μl of a suspension 5 containing lead iodide two-dimensional material 5-1 with a water solution concentration of 1 mg / ml is dropped onto the pretreated suspended structure 3-1; Figure 3 As shown in (c), the target sample in the suspension 5 containing the low-dimensional material 5-1 of lead iodide was picked up by a tungsten needle and placed at the suspended structure 3-1. It was found that the tungsten needle damaged the suspended structure and scratched the sample. Figure 3 As shown in (d).

[0031] Conclusion: Because tungsten needles are hard, they are prone to damaging suspended structures and scratching samples, resulting in high costs and low success and repeatability.

[0032] Comparative Example 4: A PDMS structure with a length of 0.5 mm, a width of 0.5 mm, and a height of 2 mm was attached to a glass slide. The test structure 3 was then attached to a 10 mm * 10 mm SiO2 / Si flat substrate 2 with adhesive tape 4. 10 μl of a suspension 5 containing lead iodide two-dimensional material 5-1 with a water solution concentration of 1 mg / ml was dropped onto the pretreated suspended structure 3-1. The PDMS structure was placed above the transfer platform. The end of the PDMS structure was brought into contact with the in-situ thermal test chip. The heating temperature was set to 120 °C, the heating time was 2 min, and the temperature was maintained at 120 °C for 1 min. Then, the PDMS structure was slowly lifted, and it was found that the PDMS structure had detached from the glass slide and completely landed on the test structure 3.

[0033] Conclusion: When the transfer platform is heated, the PDMS and the target sample are separated from the heating part by the substrate and the test structure 3, resulting in insufficient heat conduction. This causes the PDMS to fail to reach the target temperature and thus cannot detach from the sample.

[0034] In some embodiments, the length of the cuboid structure 1-2 of the flexible positioning and transfer rod body is between 0.5 and 1 mm, the width is between 0.1 and 0.5 mm, and the height is between 2 and 4 mm. The length of the micro cuboid synaptic units of the synaptic array microstructure 1-1 is between 0.05 and 0.1 mm, the width is between 0.1 and 0.5 mm, the height is between 0.05 and 0.1 mm, and the adjacent units are between 0.05 and 0.1 mm.

[0035] In some embodiments, the serpentine heating resistors 1-3 may also be materials with high resistance and good thermal conductivity, such as nickel-chromium alloy resistors or copper-nickel alloy resistance wires with a diameter between 0.05 and 0.1 mm.

[0036] In some embodiments, the materials of the cuboid structure 1-2 and the synaptic array microstructure 1-1 may also be high molecular polymer materials such as silicone, which have a viscous critical temperature and good elasticity.

[0037] In some embodiments, the flat substrate 2 may also be a quartz or sapphire substrate.

[0038] In some embodiments, the test structure 3 with the suspended structure 3-1 can be any type of in-situ test chip structure, such as an in-situ mechanical test chip.

[0039] In some embodiments, the suspension 5 containing the two-dimensional material 5-1 may also be an aqueous suspension or an ethanol solution containing two-dimensional materials such as graphene or molybdenum disulfide. The aqueous solution or ethanol solution has the characteristics of being volatile and leaving no residue, which can solve the problem of impurities.

[0040] In some embodiments, the energized heating resistors 1-3 are controlled to heat at a temperature of 60~200 ℃.

[0041] This method is applicable not only to the transfer of two-dimensional materials, but also to the transfer of various low-dimensional nanomaterials, including one-dimensional and zero-dimensional materials.

[0042] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A flexible positioning and transfer rod suitable for low-dimensional material transfer, characterized in that, include: The transfer rod (1) has a heating resistor (1-3) embedded inside. The end face of the transfer rod (1) used to pick up the target sample material is a synaptic array microstructure (1-1). The heating resistor (1-3) is used to heat the synaptic array microstructure (1-1) by passing electricity, so as to heat and evaporate the solution in which the target sample material is located.

2. The flexible positioning and transfer rod suitable for low-dimensional material transfer according to claim 1, characterized in that, The synaptic array microstructure (1-1) is made of a polymer material with a viscous critical temperature and elasticity.

3. The flexible positioning and transfer rod suitable for low-dimensional material transfer according to claim 2, characterized in that, The polymer material is PDMS or silicone.

4. The flexible positioning and transfer rod suitable for low-dimensional material transfer according to any one of claims 1-3, characterized in that, The main body of the transfer rod is a cuboid structure (1-2) with a height of 0.05~0.1 mm and a cross-section of a rectangle with a length of 0.5~1 mm and a width of 0.1~0.5 mm; the synaptic array microstructure (1-1) includes several cuboid synaptic units arranged at intervals, each cuboid synaptic unit having dimensions of 0.05~0.1 mm in length, 0.1~0.5 mm in width, and 0.05~0.1 mm in height, with the interval between the synaptic units being 0.05~0.1 mm.

5. The flexible positioning and transfer rod suitable for low-dimensional material transfer according to any one of claims 1-3, characterized in that, The heating resistors (1-3) are serpentine heating resistors with a diameter of 0.05~0.1 mm and made of nickel-chromium alloy or copper-nickel alloy.

6. The low-dimensional material transfer method using the flexible positioning and transfer rod according to any one of claims 1-4, characterized in that, include: A suspension of low-dimensional material target sample (5) is dropped onto the suspended structure (3-1) of the test structure (3); Using a flexible positioning and transfer rod (1), a low-dimensional material target sample is picked up from the suspension (5) under a microscope and the target sample is pulled and transferred to the target position on the suspended structure (3-1). After the synaptic array microstructure (1-1) is heated by the conductive heating resistor (1-3) and the solution evaporates, the target sample falls naturally to the target position. The target sample is in direct contact with the suspended structure (3-1) of the test structure (3), thus completing the transfer of the target sample.

7. The low-dimensional material transfer method according to claim 5, characterized in that, The suspension (5) is an aqueous suspension or ethanol solution containing low-dimensional materials.

8. The low-dimensional material transfer method according to claim 5, characterized in that, The test structure (3) is attached to the flat substrate (2) with tape (4) around its perimeter; the flat substrate (2) is a silicon, quartz or sapphire substrate.

9. The low-dimensional material transfer method according to claim 5, characterized in that, The test structure (3) is an in-situ thermal test chip or an in-situ mechanical test chip.

10. The low-dimensional material transfer method according to claim 5, characterized in that, The heating resistor (1-3) is energized to heat the temperature to 60~200 ℃.

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