A micro uniaxial strain application device for one-dimensional and two-dimensional nanomaterials

Abstract

The present invention discloses a micro uniaxial strain application device for one-dimensional and two-dimensional nanomaterials, comprising: a travel lifting platform, a pressing plate, a substrate support assembly, a travel lifting platform fixing bracket, and a flat base. The height of the travel lifting platform is controlled by rotating the knob on the travel lifting platform, thereby controlling the height of the pressing plate, and then, in combination with two fixed substrate support assemblies, a four-point stress application method can be formed on the strip elastic substrate, thereby achieving the effect of applying uniaxial strain to the strip elastic substrate. When the sample is attached to the upper surface of the substrate, uniaxial tensile stress is applied; when the sample is attached to the lower surface of the substrate, uniaxial compressive stress is applied. In addition, a digital scale is marked on the travel lifting platform, which can intuitively control and record the height of the pressing plate. Therefore, the present invention is a uniaxial tensile or uniaxial compressive stress application device with simple operation, uniform and controllable deformation, and excellent strain effect.

Description

Technical Field

[0001] The invention relates to a uniaxial strain applying device with uniform and controllable deformation amount for one-dimensional and two-dimensional nano materials. Background Art

[0002] As early as the 1950s, researchers discovered that applying stress to crystalline silicon could significantly enhance its carrier mobility, a feat that has yielded significant commercial value in practical applications. However, due to limitations in technological conditions and material preparation at the time, the overall development of strain engineering remained tepid. It wasn't until the beginning of the new century, with the rise of nanomaterials, that researchers discovered that semiconductor nanomaterials possess remarkable structural elasticity and ultimate fracture strength due to their extremely small size, large volume-to-surface ratio, and high crystal quality. This has opened up new possibilities for modulating the physical properties of materials through precise manipulation of stress. Strain-mediated modulation of the optical properties of micro- and nanomaterials has particularly garnered interest. Using strain, large-scale wavelength shifts (color change), light intensity enhancement, and polarization control can be achieved, opening new avenues for the development of flexible and wearable microelectronic devices with broad application prospects.

[0003] Due to the characteristics of nanomaterials themselves, traditional stress application methods are no longer suitable. Therefore, in order to apply ultra-large and controllable stress on nanomaterials, researchers have been committed to exploring new technical solutions. Among them, transferring the sample to a flexible substrate such as PDMS, PET, and then applying uniaxial stress to the substrate to achieve stress regulation of the sample is a more commonly used strain control method. At present, this control method is achieved through a special control device. This device basically requires a long strip of substrate material. The sample is transferred to the substrate manually or mechanically, and then stress is applied to the sample by compressing, stretching the substrate, etc., which in turn changes the lattice constant, band structure, etc. of the sample. Then, optical characterization methods are used to reflect the changes in the physical properties of the sample.

[0004] Devices using this type of control method all use a two-point bending method to apply strain to the substrate. This overall solution is relatively crude and cannot achieve uniform, controllable, and quantitative strain control. Furthermore, current control devices cannot simultaneously stretch and compress the strip substrate, meaning they cannot switch between stress and tension. Furthermore, these strain devices are large and do not work well with existing microfluorescence spectroscopy measurement systems, leaving significant room for improvement. Summary of the Invention

[0005] The purpose of the present invention is to overcome the problem that existing strain devices cannot achieve uniform and controllable strain regulation with free switching of stress and tension. A quantifiable four-point bending micro strain regulation device is proposed, which can apply uniform and controllable uniaxial strain to samples of one-dimensional and two-dimensional nanomaterials.

[0006] Compared to traditional two-point and three-point bending, the four-point bending method proposed in this invention applies stress more evenly, enabling precise arc deformation of the elastic substrate. Furthermore, when using traditional strain control devices, the magnitude of the applied stress is a very important value. Currently, the most commonly used method assumes that the radius of curvature (R) of the strip elastic substrate is greater than the thickness (h) of the elastic substrate, and that the primary deformation of the elastic substrate is in the longitudinal direction. This means that shear stress and stress perpendicular to the neutral axis can be ignored. Based on these assumptions, the stress formula can be derived as follows:

[0007] ε=h / 2R

[0008] However, the current calculation of the curvature radius R is done by manually measuring the substrate bending height and the width of the elastic substrate after bending, thereby estimating the curvature radius and then obtaining the stress magnitude. However, this method is subject to large manual errors. To overcome the above problems, the present invention provides a scale on the strain gauge. The bending height H of the elastic substrate can be directly read according to the change in the scale value. In addition, the height of the elastic substrate after bending is directly selected from the distance L between the two pressing plates, as shown in FIG. Figure 1 This can effectively reduce the error caused by manual measurement and greatly improve accuracy.

[0009] To achieve the above objectives, the present invention provides a micro-strain control device, characterized by comprising: a travel lift platform, a pressure plate, a substrate support assembly, a travel lift platform fixing bracket, and a flat base. The two right-angle travel lift platform fixing brackets are screwed to the bottom edges of the brackets; the two travel lift platforms are screwed to the sides of the travel lift platform fixing brackets; the two pressure plates are L-shaped, with small holes in their sides, and are screwed to the travel lift platforms; and the two substrate support assemblies are symmetrically screwed to either side of the center of the flat base.

[0010] A strip substrate with a nanomaterial sample is placed on two substrate support assemblies. Turning the knob on the travel lift causes the press plate to descend, pressing against the strip substrate. Further turning the knob bends the strip substrate. When the nanomaterial sample is attached to the top surface of the strip substrate, it experiences tensile strain; when attached to the bottom surface, it experiences compressive strain.

[0011] The above device also has the following characteristics:

[0012] 1) There is a digital scale display on the travel lifting platform, with a measuring range of 25mm and an accuracy of 1mm;

[0013] 2) The platform substrate support assembly consists of a blade and a blade base, with the blade facing upward;

[0014] This invention applies four-point bending stress to the sample through a pressing plate and substrate support assembly. Precisely defined arc geometry, combined with a digital scale display on the travel lift, ultimately achieves uniform and controllable strain control of the sample. Furthermore, the device integrates uniaxial tensile and uniaxial compressive strain, applying different types of stress to the sample when attached to the upper and lower surfaces of the strip substrate.

[0015] The present invention features a high degree of miniaturization and integration, with three-dimensionally adjustable overall position, making it convenient for use with microscopic spectroscopy testing systems. Therefore, it can provide a simple-to-use, uniformly controllable deformation, and excellent strain effect-imparting device for uniaxial tension or uniaxial compression stress application in the fields of strain engineering and micro-nano optics. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the four-point strain mode quantification.

[0017] Figure 2 Schematic diagram of the overall structure of the strain applying device of the present invention.

[0018] Figure 3 Schematic diagram of the strip elastic substrate and sample.

[0019] Figure 4 Figure 2 is the lasing spectrum of the sample measured under different stress states.

[0020] Figure 2 Description of the mark:

[0021] 1——travel lifting platform;

[0022] 2-tablet pressing;

[0023] 3 - substrate support assembly;

[0024] 4--Travel lifting platform fixing bracket;

[0025] 5--Flat base. DETAILED DESCRIPTION

[0026] 1. Combine with Figure 2 The specific implementation method of the present invention is described in detail, and the specific steps are as follows:

[0027] 1) First, transfer the micro-nano sample to a strip elastic substrate by manual transfer or mechanical peeling, such as Figure 3 As shown. Next, place the transferred sample strip elastic substrate on the substrate support assembly 3 with the sample facing upward. Then, rotate the knob on the travel lift 1 to move the pressing plate 2 downward. The two substrate support assemblies 3 at the bottom and the two pressing plates 2 at the top secure the strip elastic substrate. At this point, the strip elastic substrate is in a strain-free state. Then, place the device under a microscope with the opening facing upward.

[0028] 2) Next, slowly rotate the knob on the travel lifting platform 1 to control the distance that the pressing plate 2 moves downward. In the process of the pressing plate 2 slowly moving downward, the blades on the two substrate support components 3 are used. Under the joint action of these four points, the strip elastic substrate will undergo uniform bending deformation. The side of the strip elastic substrate where the micro-nano sample is prepared will undergo uniaxial tensile strain, and the tensile strain will be transferred to the micro-nano sample accordingly, thus achieving uniaxial tensile strain on the micro-nano sample. In addition, we can also know the distance that the pressing plate 2 has descended based on the digital scale on the travel lifting platform 1, and then the magnitude of the applied stress can be obtained through corresponding calculations. After completing the corresponding various characterizations and measurements under tensile strain, slowly rotate the knob of the travel lifting platform 1, the pressing plate 2 slowly rises, and the strip elastic substrate is also slowly released until it returns to a flat state.

[0029] 3) Repeat the above sample transfer process to obtain the strip elastic substrate after sample preparation. At this time, the strip elastic substrate is still placed on the substrate support assembly 3, but the sample is now attached to the back of the strip substrate. Then rotate the knob of the travel lifting platform 1 to slowly move the pressing plate 2 downward until the strip elastic substrate is fixed. It is worth noting that at this time, the stretching device is turned over and placed under the microscope with the opening facing downward. Next, under the joint action of the pressing plate 2 and the substrate support assembly 3, the strip elastic substrate undergoes uniform bending deformation. The side of the strip elastic substrate where the micro-nano sample is prepared will undergo uniaxial compressive strain, and the compressive strain will be transferred to the micro-nano sample accordingly, thus achieving uniaxial compressive strain on the micro-nano sample. Similar to the operation of uniaxial tensile strain, the magnitude of the compressive stress can also be calculated using the digital scale on the travel lifting platform 1. After completing the corresponding various characterizations and measurements under compressive strain, slowly rotate the knob of the travel lifting platform 1 until the strip elastic substrate returns to flatness.

[0030] 2. Figure 4 The following are lasing spectra of the sample measured under different stress states. The lasing behavior under no strain, tensile strain, and compressive strain can be clearly seen.

[0031] 3. The four-point uniformly controllable stress application device provided by the present invention can be used to apply uniaxial tensile strain and uniaxial compressive strain to one-dimensional and two-dimensional nanomaterials, and is suitable for use with a microscopic spectroscopy testing system to characterize and explore the properties of nanomaterials under different strain states. It has broad application prospects in the entire field of strain engineering and micro-nano optics.

[0032] 4. The above description is only a preferred example of the present invention and does not limit the scope of application of the present invention. Any modification, replacement, improvement, etc. made using the contents of the description and drawings of the present invention, or direct or indirect application in other related technical fields, are also included in the scope of protection of the present invention.

Claims

1. A micro uniaxial strain application device suitable for one-dimensional and two-dimensional nanomaterials, comprising: A travel lifting platform (1), a pressing plate (2), a substrate support assembly (3), a travel lifting platform fixing bracket (4), and a flat base (5), characterized in that: The travel lift platform fixing bracket (4) is a right-angled bracket and there are two of them, and their bottom edges are fixed to the two ends of the flat base (5) by screws; the two travel lift platforms (1) are fixed to the side edges of the travel lift platform fixing bracket (4) by screws respectively; there are two pressing plates (2) in an L-shape, with small holes on the side surfaces, which are fixed to the travel lift platform (1) by screws; the two substrate support assemblies (3) are symmetrically fixed to the two sides of the center position of the flat base by screws; When used, the micro uniaxial strain applying device applicable to one-dimensional and two-dimensional nanomaterials: The sample transfer process is as follows: first, the nanomaterial sample is transferred to the strip elastic substrate by manual transfer or mechanical stripping, then the strip elastic substrate with the transferred sample is placed on the substrate support assembly (3) with the sample facing upward, then the pressing plate (2) is moved downward by rotating the knob on the travel lifting platform (1), and the strip elastic substrate is fixed by the two substrate support assemblies (3) at the bottom and the two pressing plates (2) at the top, at this time the strip elastic substrate is in a strain-free state, and then the device is placed under a microscope with the opening facing upward; The strip elastic substrate with the nanomaterial sample is placed on two substrate support assemblies (3). The knob on the travel lifting platform (1) is continuously rotated, and the travel lifting platform drives the pressing plate (2) to continue to descend, and the bottom of the strip elastic substrate is bent. When the nanomaterial sample is attached to the upper surface of the strip elastic substrate, the sample is subjected to tensile strain, and when the material sample is attached to the lower surface of the strip substrate, the sample is subjected to compressive strain. The distance the pressing plate (2) descends is known according to the digital scale on the travel lifting platform (1), and the magnitude of the applied stress can be obtained through corresponding calculations. After completing various corresponding characterizations and measurements under tensile strain, the knob of the travel lifting platform (1) is slowly rotated, and the pressing plate (2) slowly rises, and the strip elastic substrate is also slowly released until it returns to a flat state. Repeat the above sample transfer process to obtain the strip elastic substrate after sample preparation. At this time, the strip elastic substrate is still placed on the substrate support assembly (3), but the sample is now attached to the reverse side of the strip elastic substrate; then rotate the knob of the travel lift (1) to slowly move the pressing plate (2) downward until the strip elastic substrate is fixed; at this time, the device is turned over and placed under the microscope with the opening facing downward; then, similarly, under the joint action of the pressing plate (2) and the substrate support assembly (3), the strip elastic substrate undergoes uniform bending deformation, and the side of the strip elastic substrate on which the micro-nano sample is prepared will undergo uniaxial compressive strain, which will correspondingly transfer the compressive strain to the micro-nano sample, thereby achieving uniaxial compressive strain on the micro-nano sample; similar to the operation of uniaxial tensile strain, the magnitude of the compressive stress is calculated by the digital scale on the travel lift (1); after completing the corresponding various characterizations and measurements under the compressive strain, slowly rotate the knob of the travel lift (1) until the strip elastic substrate returns to a flat state.

2. The micro uniaxial strain applying device for one-dimensional and two-dimensional nanomaterials according to claim 1, characterized in that There is a digital scale display on the travel lifting platform (1), with a measuring range of 25mm and an accuracy of 1mm.

3. The micro uniaxial strain applying device for one-dimensional and two-dimensional nanomaterials according to claim 1, characterized in that The substrate support assembly (3) is composed of a blade and a blade base, and the blade is directed upward.

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