In-situ mechanical loading device and in-situ transmission electron microscope heating rod

Abstract

This invention relates to the field of micro / nano mechanical measurement technology, and particularly to an in-situ mechanical loading device and an in-situ transmission electron microscope heating rod. The in-situ mechanical loading device includes a deformation plate, which comprises a substrate, a measuring plate, a conductive plate, and at least one pair of cantilever beams. The conductive plate includes a first conductive part and a second conductive part connected sequentially along its axial direction. Two cantilever beams in each pair are respectively disposed on both sides of the second conductive part, and the second conductive part is connected to the substrate through the cantilever beams. The extension direction of each cantilever beam is perpendicular to the axial direction of the conductive plate. The measuring plate is connected to the substrate and surrounds the outside of the first conductive part with a gap between them. The measuring plate and the first conductive part are suitable for connecting a specimen. A loading plate is also included, with one end connected to the second conductive part and the other end connected to the substrate. The design of the cantilever beams ensures that the specimen is always subjected to an axial tensile load during the tensile process, improving measurement accuracy and solving the problem of misalignment of in-situ tensile loads at the nanoscale.

Description

Technical Field

[0001] This invention relates to the field of micro-nano mechanical measurement technology, and in particular to an in-situ mechanical loading device and an in-situ transmission electron microscope heating rod. Background Technology

[0002] With the rapid development of microelectronics technology, the size of microelectronic device units is getting smaller and smaller. For example, the channel size of field-effect transistors has reached the order of several nanometers. Since the mechanical properties of the materials of the devices are an important basis for ensuring their normal operation, it is essential to measure, characterize, and explore the mechanical deformation laws at the nanoscale. However, at such a small scale, it is very difficult to accurately measure and characterize the mechanical parameters of the materials.

[0003] The development of transmission electron microscopy (TEM) has enabled researchers to precisely observe and dissect the atomic crystal structures of materials at the nanoscale and even atomic scale, providing an excellent platform for understanding the nanoscale and atomic world. A TEM sample holder is a small experimental stage for observing nanoscale samples. Samples are often thinned and placed within a 3 mm diameter circular area at the front end of the sample holder. The sample holder is inserted into the chamber, with the front end positioned between the pole pieces. A high-energy electron beam penetrates the sample, interacting with it, and the transmitted electrons are collected to obtain information about the sample morphology and crystal structure. Ordinary sample holders can only observe static samples. To study the dynamic structure and deformation evolution mechanisms of nanomaterials under different environments or conditions, in-situ transmission loading rods have emerged. These rods introduce signal interfaces within the loading rod, creating an in-situ loading region at the front end of the sample.

[0004] In-situ mechanical loading rods are typical sample rods used to apply mechanical loads at the nanoscale. By applying loads to samples, corresponding in-situ mechanical experiments can be performed, allowing observation of the sample's evolution and a better understanding of its deformation mechanisms. Generally, in-situ mechanical sample rods require an embedded mechanical driving loading device, typically using piezoelectric drive modules or stepper motors, and micro-cantilever piezoresistive or capacitive sensors for load sensing. Due to the complex internal structure of these loading rods, they can generally only tilt or cannot rotate, making it extremely difficult to achieve atomic-scale resolved mechanical loading experiments. Furthermore, achieving micro-force measurements at the nanonewton level and below remains very challenging. Summary of the Invention

[0005] This invention provides an in-situ mechanical loading device and an in-situ transmission electron microscope heating rod to solve one of the defects in the prior art. The design of the cantilever beam ensures that the specimen is always subjected to an axial tensile load during the tensile process, and can achieve an ultra-high displacement driving accuracy of less than 1 nm, effectively improving the measurement accuracy and solving the problem of in-situ tensile load misalignment and load measurement difficulties at the nanoscale.

[0006] This invention provides an in-situ mechanical loading device, comprising:

[0007] A deformation plate includes a substrate, a measuring plate, a conductive plate, and at least one pair of cantilever beams. The conductive plate includes a first conductive portion and a second conductive portion connected sequentially along its axial direction. Two of the cantilever beams in each pair are respectively disposed on both sides of the second conductive portion. The second conductive portion is connected to the substrate through the cantilever beams. The extension direction of each cantilever beam is perpendicular to the axial direction of the conductive plate. The measuring plate is connected to the substrate. The measuring plate surrounds the outside of the first conductive portion and has a gap with the first conductive portion. The measuring plate and the first conductive portion are adapted to connect a specimen.

[0008] A loading piece, one end of which is connected to the second conductive part and the other end of which is connected to the substrate.

[0009] According to an in-situ mechanical loading device provided by the present invention, the measuring plate includes:

[0010] A first measuring part, the extension direction of the first measuring part being perpendicular to the axial direction of the conductive sheet, a first gap being formed between the first measuring part and the first conductive part, the first measuring part and the first conductive part being adapted to connect a specimen to be measured for tensile and compressive loads;

[0011] The second measuring part extends in a direction perpendicular to the axis of the conductive sheet, and a second gap is formed between the second measuring part and the first conductive part. The second measuring part and the first conductive part are adapted to connect the specimen to be measured for shear and bending loads.

[0012] According to an in-situ mechanical loading device provided by the present invention, the width of the first conductive part along the axial direction perpendicular to the conductive sheet is greater than the width of the second conductive part along the axial direction perpendicular to the conductive sheet.

[0013] According to an in-situ mechanical loading device provided by the present invention, the two ends of the first conductive part symmetrically protrude from both sides of the second conductive part.

[0014] According to an in-situ mechanical loading device provided by the present invention, the measuring plate includes two second measuring parts, which are symmetrically connected to the two ends of the first measuring part, and the two second measuring parts respectively correspond to the two ends of the first conductive part.

[0015] According to an in-situ mechanical loading device provided by the present invention, both the first gap and the second gap are rectangular in shape.

[0016] According to an in-situ mechanical loading device provided by the present invention, the deformation plate includes two pairs of suspension beams, and the loading plate is disposed between the two pairs of suspension beams.

[0017] According to an in-situ mechanical loading device provided by the present invention, two of the two suspension beams in each pair are symmetrically connected to the second conductive part.

[0018] According to an in-situ mechanical loading device provided by the present invention, the loading plate comprises:

[0019] First metal sheet;

[0020] The second metal sheet is arranged sequentially along the axial direction of the conductive sheet, and the second metal sheet and the first metal sheet are connected in parallel on the same plane. The coefficients of thermal expansion of the second metal sheet and the first metal sheet are different.

[0021] The present invention also provides an in-situ transmission electron microscope heating rod, including the in-situ mechanical loading device as described above.

[0022] The above-described one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects:

[0023] The in-situ mechanical loading device of this invention mainly consists of a deformation plate and a loading plate. The deformation plate mainly consists of a substrate, a measuring plate, a conductive plate, and at least one pair of suspension beams. The substrate serves as the fixed foundation for the measuring plate, the conductive plate, and the suspension beams. The conductive plate is divided into a first conductive part and a second conductive part along its axial direction. One end of the suspension beam is connected to the second conductive part, and the other end is connected to the substrate, thereby realizing the connection between the conductive plate and the substrate. The two suspension beams form a pair of suspension beams. The two suspension beams are respectively set on both sides of the second conductive part, and the extension direction of the suspension beams is perpendicular to the axial direction of the conductive plate. There is a certain distance between the measuring plate and the first conductive part. The two ends of the specimen are respectively connected to the first conductive part and the measuring plate. One end of the loading plate is fixed on the substrate, and the other end is connected to the first conductive part.

[0024] Define the axis of the conductive plate as the horizontal direction and the direction perpendicular to the axis of the conductive plate as the vertical direction. The conductive plate extends laterally in the horizontal direction, and the suspension beam extends longitudinally in the vertical direction. The loading plate can deform under temperature changes, and this deformation generates a driving force on the conductive plate. This driving force can cause the conductive plate to move in both the horizontal and vertical directions. Because the suspension beam constrains the movement of the second conductive part in the vertical direction, the conductive plate cannot move vertically. That is, under the action of the suspension beam, the driving force generated by the loading plate can only cause the conductive plate to move horizontally, thus loading the specimen. For the specimen connected between the measuring plate and the first conductive part, during tensile or compressive load measurement, the specimen is always subjected to an axial tensile or compressive load, ensuring complete alignment of the specimen during tensile and compressive loading. By observing the deformation of the measuring plate, the corresponding load on the specimen can be calculated.

[0025] This invention can be applied to in-situ tensile testing and mechanical load measurement of nanoscale specimens under transmission electron microscopy. It provides a temperature-driven in-situ mechanical loading device for transmission electron microscopy, capable of achieving large-range displacement loading within a relatively low temperature range. Only a small temperature load is required, for example, a temperature increment of around 30°C, to achieve a displacement stroke greater than 2 μm for the conductive plate. Furthermore, by controlling the temperature, the loading displacement resolution can reach the angstrom level. The cantilever design ensures that the specimen is always subjected to axial tensile load during the tensile process, achieving ultra-high displacement driving accuracy of less than 1 nm, effectively improving measurement accuracy and solving the problem of in-situ tensile load misalignment and difficult load measurement at the nanoscale.

[0026] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the deformation plate of the in-situ mechanical loading device provided in an embodiment of the present invention;

[0029] Figure 2 This is a schematic diagram of the in-situ mechanical loading device provided in an embodiment of the present invention;

[0030] Figure 3This is a schematic diagram of the in-situ mechanical loading device for loading a specimen according to an embodiment of the present invention;

[0031] Figure 4 This is a diagram showing that the first gap distance of the in-situ mechanical loading device provided in this embodiment of the invention is 0.87 micrometers during a 30°C no-load test.

[0032] Figure 5 This is a diagram showing the first gap distance of 1.13 micrometers during the 60°C no-load test of the in-situ mechanical loading device provided in this embodiment of the invention.

[0033] Figure label:

[0034] 100. Deformation plate; 110. Substrate; 120. Measuring plate; 121. First measuring part; 122. Second measuring part; 130. Conducting plate; 131. First conducting part; 132. Second conducting part; 140. Suspension beam; 151. First gap; 152. Second gap; 153. First hollow part; 154. Second hollow part; 155. Third hollow part; 156. Fourth hollow part;

[0035] 200. Loading sheet; 210. First metal sheet; 220. Second metal sheet; 230. High-temperature adhesive;

[0036] 310, First specimen; 320, Second specimen. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0038] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0039] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0040] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0041] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0042] like Figure 1 , Figure 2 and Figure 3As shown, the in-situ mechanical loading device provided in this embodiment of the invention includes a deformation plate 100 and a loading plate 200. The deformation plate 100 includes a substrate 110, a measuring plate 120, a conductive plate 130, and at least one pair of suspension beams 140. The conductive plate 130 includes a first conductive part 131 and a second conductive part 132 connected sequentially along its axial direction. Two of the two suspension beams 140 in each pair are respectively disposed on both sides of the second conductive part 132. The second conductive part 132 is connected to the substrate 110 through the suspension beams 140. The extension direction of each suspension beam 140 is perpendicular to the axial direction of the conductive plate 130. The measuring plate 120 is connected to the substrate 110. The measuring plate 120 surrounds the outside of the first conductive part 131 and has a gap with the first conductive part 131. The measuring plate 120 and the first conductive part 131 are suitable for connecting a specimen. One end of the loading plate 200 is connected to the second conductive part 132, and the other end is connected to the substrate 110.

[0043] The in-situ mechanical loading device of this invention mainly consists of a deformation plate 100 and a loading plate 200. The deformation plate 100 mainly consists of a base plate 110, a measuring plate 120, a conductive plate 130, and at least one pair of suspension beams 140. The base plate 110 serves as the fixed foundation for the measuring plate 120, the conductive plate 130, and the suspension beams 140. The conductive plate 130 is divided into a first conductive part 131 and a second conductive part 132 along its axial direction. One end of the suspension beam 140 is connected to the second conductive part 132, and the other end is connected to the base plate 110. This achieves the connection between the conductive plate 130 and the substrate 110. The two suspension beams 140 form a pair of suspension beams 140. The two suspension beams 140 are respectively set on both sides of the second conductive part 132, and the extension direction of the suspension beams 140 is perpendicular to the axis of the conductive plate 130. The measuring plate 120 is at a certain distance from the first conductive part 131. The two ends of the specimen are respectively connected to the first conductive part 131 and the measuring plate 120. One end of the loading plate 200 is fixed on the substrate 110, and the other end is connected to the first conductive part 131.

[0044] Define the axis of the conductive plate 130 as the horizontal direction and the direction perpendicular to the axis of the conductive plate 130 as the vertical direction. The conductive plate 130 extends laterally in the horizontal direction, and the suspension beam 140 extends longitudinally in the vertical direction. The loading plate 200 can deform under temperature changes, and this deformation generates a driving force on the conductive plate 130. This driving force allows the conductive plate 130 to move in both the horizontal and vertical directions. Because the suspension beam 140 constrains the movement of the second conductive part 132 in the vertical direction, the conductive plate 130 cannot move in the vertical direction. That is, under the action of the suspension beam 140, the driving force generated by the loading plate 200 can only cause the conductive plate 130 to move horizontally, thereby loading the specimen. For the specimen connected between the measuring plate 120 and the first conductive part 131, during the tensile or compressive load measurement process, the specimen is always subjected to an axial tensile or compressive load, ensuring complete alignment of the specimen during tensile and compressive loading. By observing the deformation of the measuring plate 120, the load on the corresponding specimen can be calculated.

[0045] This invention can be applied to in-situ tensile testing and mechanical load measurement of nanoscale specimens under transmission electron microscopy. It provides a temperature-driven in-situ mechanical loading device for transmission electron microscopy, capable of achieving large-range displacement loading within a relatively low temperature range. Only a small temperature load is required, for example, a temperature increment of around 30°C, to achieve a displacement stroke greater than 2 μm for the conductive plate 130. Furthermore, by controlling the temperature, the loading displacement resolution can reach the angstrom level. The design of the cantilever beam 140 ensures that the specimen is always subjected to an axial tensile load during the tensile process, achieving an ultra-high displacement driving accuracy of less than 1 nm, effectively improving measurement accuracy and solving the problem of in-situ tensile load misalignment and difficult load measurement at the nanoscale.

[0046] In this embodiment, the substrate 110, measuring piece 120, conductive piece 130, and at least one pair of cantilever beams 140 are all obtained on a metal sheet by metal etching. After etching the measuring piece 120, conductive piece 130, and at least one pair of cantilever beams 140 onto the metal sheet, the remaining portion is the substrate 110. The metal sheet is a non-magnetic metal material with a thickness of 30 μm and a diameter of 3 mm, such as copper, molybdenum, or tungsten. The dimensions of each cantilever beam 140 can be designed according to actual needs, generally with a length of 800 μm, a width of 30 μm, and a thickness of 30 μm. The measuring piece 120 has dimensions of 300 μm in length, 10 μm in width, and 10 μm in thickness. It is first obtained by metal etching to obtain a preliminary pattern shape with a length of 300 μm, a width of 20 μm, and a thickness of 30 μm, and then further refined by FIB (Focused Ion Beam) etching to etch the structure of the measuring piece 120.

[0047] According to one embodiment of the present invention, the measuring plate 120 includes a first measuring part 121 and a second measuring part 122. The extending direction of the first measuring part 121 is perpendicular to the axial direction of the conductive plate 130. A first gap 151 is formed between the first measuring part 121 and the first conductive part 131. The first measuring part 121 and the first conductive part 131 are adapted to connect a specimen to be measured under tensile and compressive loads. The extending direction of the second measuring part 122 is perpendicular to the axial direction of the conductive plate 130. A second gap 152 is formed between the second measuring part 122 and the first conductive part 131. The second measuring part 122 and the first conductive part 131 are adapted to connect a specimen to be measured under shear and bending loads.

[0048] In this embodiment, the measuring plate 120 is mainly composed of a first measuring part 121 and a second measuring part 122. The axial direction of the conductive plate 130 is defined as the horizontal direction, and the direction perpendicular to the axial direction of the conductive plate 130 is defined as the vertical direction. The first measuring part 121 extends in the vertical direction and has a first gap 151 between it and the first conductive part 131. The second measuring part 122 extends in the vertical direction and has a second gap 152 between it and the first conductive part 131.

[0049] When the first specimen 310 is connected between the first measuring part 121 and the first conducting part 131, the first specimen 310 is fixed in the horizontal direction. The axial load generated by the conducting piece 130 is in the horizontal direction, forming a tensile or compressive load on the first time. Therefore, when the first specimen 310 is set on the first measuring part 121, the in-situ mechanical loading device can provide in-situ tensile and compressive mechanical loading modes.

[0050] When the second specimen 320 is connected between the second measuring part 122 and the first conductive part 131, the second specimen 320 is fixed in the vertical direction. The axial load generated by the conductive piece 130 is in the horizontal direction, and the direction of the axial load is perpendicular to the extension direction of the second specimen 320, forming a shear or bending load on the second specimen 320. Therefore, when the second specimen 320 is set on the second measuring part 122, the in-situ mechanical loading device can provide in-situ shear and bending mechanical loading modes.

[0051] This invention can provide simple yet accurate mechanical loading schemes such as tension, compression, shear, and bending. It can be flexibly applied to the mechanical loading measurement and real-time characterization of various nanoscale materials under in-situ transmission electron microscopy, which is conducive to the diversification of loading methods and is of great significance for future high-throughput in-situ transmission electron microscopy characterization of nanomechanical materials.

[0052] In this embodiment, a first hollow portion 153, a second hollow portion 154, a third hollow portion 155, and a fourth hollow portion 156 are formed on a metal sheet by metal etching. That is, the substrate 110 is separated from the measuring piece 120, the conductive piece 130, and the cantilever beam 140 by hollow portions. The first hollow portion 153 and the second hollow portion 154 together enclose the first measuring portion 121. The second hollow portion 154 encloses the first conductive portion 131, a portion of the second conductive portion 132, and the second measuring portion 122. The third hollow portion 155 and the second hollow portion 154 together enclose a pair of cantilever beams 140. The third hollow portion 155 encloses a portion of the second conductive portion 132. The third hollow portion 155 and the fourth hollow portion 156 together enclose another pair of cantilever beams 140. The fourth hollow portion 156 encloses a portion of the second conductive portion 132. The first gap 151 and the second gap 152 are both part of the second hollow portion 154.

[0053] According to one embodiment of the present invention, the width of the first conductive portion 131 along the axial direction perpendicular to the conductive sheet 130 is greater than the width of the second conductive portion 132 along the axial direction perpendicular to the conductive sheet 130. In this embodiment, the axial direction of the conductive sheet 130 is defined as its length direction, and the direction perpendicular to the axial direction of the conductive sheet 130 is defined as its width direction. Therefore, the horizontal direction is the length direction of the conductive sheet 130, and the vertical direction is the width direction of the conductive sheet 130. The width of the first conductive portion 131 is greater than the width of the second conductive portion 132, which means that the first conductive portion 131 can extend and protrude beyond the second conductive portion 132 in its width direction.

[0054] The first conductive part 131 is connected to one end of the specimen. The first conductive part 131 can protrude vertically from the second conductive part 132, further increasing the usable area for connection and fixation with the specimen. At the same time, it provides more position and space for the first measuring part 121 and the second measuring part 122 to be connected to the first conductive part 131 through the specimen, avoiding mutual interference.

[0055] According to one embodiment of the present invention, the two ends of the first conductive portion 131 symmetrically protrude from both sides of the second conductive portion 132. In this embodiment, the second conductive portion 132 is a rectangular strip and extends horizontally, and the first conductive portion 131 is also a rectangular strip and extends vertically. One end of the second conductive portion 132 is connected to the middle of the first conductive portion 131, thereby connecting the first conductive portion 131 and the second conductive portion 132 to form an inverted T-shaped conductive sheet 130.

[0056] Both ends of the first conductive portion 131 protrude beyond the second conductive portion 132 in the width direction of the conductive plate 130, forming a double-sided protrusion in the width direction of the second conductive portion 132. The two ends have the same extension length in the width direction, forming a symmetrical T-shaped structure. This further increases the usable area for connection and fixation with the specimen, while providing more position and space for the first measuring portion 121 and the second measuring portion 122 to connect with the first conductive portion 131 through the specimen. Furthermore, the symmetrical conductive plate 130 provides more stable and reliable load transmission.

[0057] In other embodiments, the shape of the conductive sheet 130 can be designed according to actual needs, and can also be a rectangular strip with a uniform width, or a bent strip with one side protruding in the width direction.

[0058] According to an embodiment of the present invention, the measuring piece 120 includes two second measuring portions 122, which are symmetrically connected to the two ends of the first measuring portion 121. The two second measuring portions 122 correspond to the two ends of the first conductive portion 131, respectively. In this embodiment, the measuring piece 120 mainly consists of one first measuring portion 121 and two second measuring portions 122. The first measuring portion 121 extends vertically, and the second measuring portions 122 extend vertically. The two ends of the first measuring portion 121 are respectively connected to the substrate 110. The first measuring portion 121 is opposite to and parallel to the first conductive portion 131. The ends of the two second measuring portions 122 are both connected to the substrate 110. That is, the two second measuring portions 122 are respectively disposed in the vertical extension direction of the first conductive portion 131 and respectively correspond to the ends of the first conductive portion 131. The range of the first measuring portion 121 in the vertical direction corresponds to the entire first conductive portion 131.

[0059] The combined structure of the first measuring part 121 and the second measuring part 122 surrounds the first conductive part 131 on three sides, further increasing the usable area for connection and fixation with the specimen. It also provides more position and space for the first measuring part 121 and the second measuring part 122 to connect with the first conductive part 131 via the specimen. With the first conductive part 131 extending symmetrically vertically at the ends of the second conductive parts 132, the two second measuring parts 122 are also symmetrically arranged relative to the first measuring part 121, forming a symmetrical measuring plate 120. This symmetrical structure allows for more stable and reliable load transmission.

[0060] According to one embodiment of the present invention, both the first gap 151 and the second gap 152 are rectangular in shape. In this embodiment, the adjacent edges of the first measuring part 121 and the first conducting part 131 are designed as straight lines to form the rectangular first gap 151, and the adjacent edges of the second measuring part 122 and the first conducting part 131 are designed as straight lines to form the rectangular second gap 152.

[0061] After the load is applied, the deformation of the measuring piece 120 under the load of the specimen can directly affect the shape of the first gap 151 and the second gap 152, thereby destroying the original rectangular shape, or significantly increasing or decreasing the distance between the first gap 151 and the second gap 152, making the deformation more obvious, making the displacement of the measuring piece 120 more intuitive and clear, facilitating observation and measurement, and thus improving the measurement accuracy.

[0062] According to an embodiment of the present invention, the deformation plate 100 includes two pairs of suspension beams 140, and a loading plate 200 is disposed between the two pairs of suspension beams 140. In this embodiment, the deformation plate 100 mainly consists of a substrate 110, a measuring plate 120, a conductive plate 130, and two pairs of suspension beams 140. Both pairs of suspension beams 140 are connected to the second conductive part 132, providing connections between the second conductive part 132 and the substrate 110 at multiple locations, making the constraint force of the suspension beams 140 on the conductive plate 130 more balanced on the second conductive part 132, and the constraint effect more significant. The loading plate 200 is disposed between the two pairs of suspension beams 140, and the driving force of the loading plate 200 on the conductive plate 130 can be constrained in the horizontal direction by the front and rear of the loading plate 200, further improving the constraint effect of the suspension beams 140 on the vertical movement of the conductive plate 130.

[0063] In this embodiment, two pairs of suspension beams 140 are evenly distributed on the second conductive part 132 to ensure a uniform distribution of the constraint force on the second conductive part 132. In other embodiments, the number of pairs of suspension beams 140 is set according to actual needs, but should not be too many. Too many suspension beams 140 will not only constrain the displacement of the conductive piece 130 in the vertical direction, but may also constrain the displacement of the conductive piece 130 in the horizontal direction, thereby affecting the load applied by the conductive piece 130 to the specimen.

[0064] According to one embodiment of the present invention, two of the two suspension beams 140 in each pair are symmetrically connected to the second conductive part 132. In this embodiment, each pair of suspension beams 140 consists of two suspension beams 140 arranged opposite each other on both sides of the second conductive part 132. To ensure the balance of the force on the conductive piece 130 and the stability of the connection of the suspension beams 140, the suspension beams 140 are arranged in a symmetrical form.

[0065] In this embodiment, two pairs of suspension beams 140 connect the substrate 110 and the conductive sheet 130, thereby forming a double-symmetrical metal ring structure. In other embodiments, each pair of suspension beams 140 may also consist of two non-opposing suspension beams 140, with a certain vertical distance between the two suspension beams 140. After multiple pairs of suspension beams 140 are connected to the second conductive part 132, they form suspension beams 140 spaced apart on both sides of the second conductive part 132.

[0066] According to an embodiment of the present invention, the loading plate 200 includes a first metal plate 210 and a second metal plate 220. The first metal plate 210 and the second metal plate 220 are arranged sequentially along the axial direction of the conductive plate 130, and the second metal plate 220 and the first metal plate 210 are connected in parallel on the same plane. The coefficients of thermal expansion of the second metal plate 220 and the first metal plate 210 are different.

[0067] In this embodiment, the loading plate 200 is a bimetallic structure composed of a first metal plate 210 and a second metal plate 220. The first metal plate 210 and the second metal plate 220 are connected in parallel in the same plane. Due to the different coefficients of thermal expansion between the second metal plate 220 and the first metal plate 210, the thermal deformation of the materials is inconsistent. Therefore, when the temperature rises, the deformation degrees of the first metal plate 210 and the second metal plate 220 are different. The different deformation degrees will cause the loading plate 200 to bend towards the side where the first metal plate 210 is located or the side where the second metal plate 220 is located. The end of the loading plate 200 connected to the substrate 110 remains fixed, while the end connected to the second conductive part 132 bends and deflects, thereby generating a driving force on the conductive plate 130, and thus applying a load to the specimen.

[0068] The side containing the first metal sheet 210 is closer to the first conductive part 131, and the side containing the second metal sheet 220 is farther from the first conductive part 131. When the loading piece 200 bends towards the side containing the first metal sheet 210, the conductive piece 130 is driven closer to the first measuring part 121 to apply a compressive load to the first specimen 310. When the loading piece 200 bends towards the side containing the second metal sheet 220, the conductive piece 130 is driven farther from the first measuring part 121 to apply a tensile load to the first specimen 310. When temperature changes cannot cause the loading piece 200 to deform, the relative positions of the first metal sheet 210 and the second metal sheet 220 can be changed to cause the loading piece 200 to bend and deflect in a predetermined direction.

[0069] In this embodiment, the loading plate 200 has a thickness of 150 μm, a length of 1.2 mm, and a width of 200 μm. First, a corresponding bimetallic sheet is prepared. Then, the bimetallic sheet is cut into strips with a thickness of approximately 500 μm, a length of 30 mm, and a width of 200 μm using wire cutting. These strips are then cut into short rod-shaped samples with a length of 2 mm, a width of 200 μm, and a thickness of 500 μm using high-strength shears. Finally, these short rod-shaped samples are glued onto a glass slide and manually polished on metallographic sandpaper to form the loading plate 200. The self-polished loading plate 200 is then glued to the deformation plate 100 using high-temperature adhesive 230. After curing at 100°C for 1 hour, the loading plate 200 and the deformation plate 100 are firmly bonded together, forming the in-situ mechanical loading device of this invention.

[0070] This invention allows for the adjustment of the material type and size of the loading plate 200, the cantilever beam 140, and the measuring plate 120 according to the material being tested. This enables the device to achieve stable and accurate in-situ mechanical loading and load measurement, forming a complete quantitative design scheme for in-situ mechanical loading. In summary, this design scheme is ingenious, the manufacturing process is simple, and it can achieve high-precision mechanical loading and load measurement. It can realize in-situ TEM (transmission electron microscopy) mechanical characterization and load measurement of a large number of nanomaterials, especially for recently developed low-dimensional materials, making it an effective in-situ mechanical loading device. This invention uses laser etching combined with manual grinding to form the corresponding loading plate 200, enabling in-situ mechanical load measurement and in-situ atomic-scale observation of various materials at the nanoscale, which is of great significance for the development of in-situ transmission electron microscopy technology.

[0071] After fabricating the in-situ mechanical loading device, the specimen is prepared. For general metallic materials, FIB processing can be used for sample preparation. First, a large block sample is placed in the FIB electron microscope chamber and milled with an ion beam to form a corresponding micron-sized plate-like specimen. Then, a nanorobot is used to extract the plate-like specimen and fix it to both sides of the first gap 151 or the second gap 152 on the in-situ mechanical loading device. After fixing the two ends of the specimen with FIB ion beam assisted deposition, the corresponding area of ​​the first gap 151 or the second gap 152 on the specimen is thinned using the FIB ion beam. Initially, a high beam current is used for thinning. When the thickness of the thinned area drops to around 150 nanometers, a low beam current is used for thinning until the thickness of the thinned area reaches about 60 nanometers. Then, FIB pattern etching is used to process the corresponding dog bone-shaped specimen. For two-dimensional materials, the material can also be transferred to the corresponding location using a wet transfer method, followed by cleaning with organic solvents such as acetone.

[0072] The in-situ transmission electron microscope heating rod provided by the present invention is described below. The in-situ transmission electron microscope heating rod described below can be referred to in correspondence with the in-situ mechanical loading device described above.

[0073] This invention also provides an in-situ transmission electron microscope heating rod, including the in-situ mechanical loading device as described in the above embodiments.

[0074] After the specimen is prepared, the in-situ mechanical loading device and the specimen are placed together into the heating rod of the in-situ transmission electron microscope (TEM), such as the Gatan 652 heating rod. The front end of the heating rod is equipped with a corresponding crucible structure as the sample area. The fabricated in-situ mechanical loading device containing the specimen is placed into the crucible, and the screws are tightened to complete the sample installation. When conducting in-situ experiments under the TEM, the temperature of the sample area can be accurately adjusted through the temperature control system of the heating rod, with an accuracy of 0.1℃. The rate of temperature rise can be adjusted according to the requirements of the test sample.

[0075] like Figure 4 and Figure 5 As shown, the unloaded in-situ mechanical loading device was tested. When the temperature increment was 30℃, the width of the first gap 151 was 0.87μm; when the temperature increment was 60℃, the width of the first gap 151 was 1.13μm. It can be found that under temperature load, the in-situ mechanical loading device can generate a driving displacement of 260 nanometers. This driving displacement is sufficient for the specimen at the nanoscale, and the ambient temperature only increased by 30℃, minimizing the influence of temperature on the mechanical properties of the specimen. With a loading step of 0.1℃, the displacement driving accuracy is a high-sensitivity driving accuracy of 0.86 nanometers.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An in-situ mechanical loading device, characterized in that, include: A deformation plate includes a substrate, a measuring plate, a conductive plate, and at least one pair of cantilever beams. The conductive plate includes a first conductive portion and a second conductive portion connected sequentially along its axial direction. Two of the cantilever beams in each pair are respectively disposed on both sides of the second conductive portion. The second conductive portion is connected to the substrate through the cantilever beams. The extension direction of each cantilever beam is perpendicular to the axial direction of the conductive plate. The measuring plate is connected to the substrate. The measuring plate surrounds the outside of the first conductive portion and has a gap with the first conductive portion. The measuring plate and the first conductive portion are adapted to connect a specimen. A loading piece, one end of which is connected to the second conductive part, and the other end of which is connected to the substrate; The measuring plate includes: A first measuring part, the extension direction of the first measuring part being perpendicular to the axial direction of the conductive sheet, a first gap being formed between the first measuring part and the first conductive part, the first measuring part and the first conductive part being adapted to connect a specimen to be measured for tensile and compressive loads; The second measuring part extends in a direction perpendicular to the axis of the conductive sheet, and a second gap is formed between the second measuring part and the first conductive part. The second measuring part and the first conductive part are adapted to connect the specimen to be measured for shear and bending loads. The width of the first conductive portion along the axial direction perpendicular to the conductive sheet is greater than the width of the second conductive portion along the axial direction perpendicular to the conductive sheet; The two ends of the first conductive part protrude symmetrically from both sides of the second conductive part; The measuring plate includes two second measuring parts, which are symmetrically connected to the two ends of the first measuring part, and the two second measuring parts correspond to the two ends of the first conductive part, respectively.

2. The in-situ mechanical loading device according to claim 1, characterized in that, Both the first gap and the second gap are rectangular in shape.

3. The in-situ mechanical loading device according to claim 1, characterized in that, The deformation plate includes two pairs of suspension beams, and the loading plate is disposed between the two pairs of suspension beams.

4. The in-situ mechanical loading device according to claim 3, characterized in that, Two of the two suspension beams in each pair are symmetrically connected to the second conductive part.

5. The in-situ mechanical loading device according to any one of claims 1 to 4, characterized in that, The loading piece includes: First metal sheet; The second metal sheet is arranged sequentially along the axial direction of the conductive sheet, and the second metal sheet and the first metal sheet are connected in parallel on the same plane. The coefficients of thermal expansion of the second metal sheet and the first metal sheet are different.

6. A heating rod for an in-situ transmission electron microscope, characterized in that, Includes the in-situ mechanical loading device as described in any one of claims 1 to 5.

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