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

Abstract

The invention relates to the technical field of micro-nano mechanical measurement, in particular to an in-situ mechanical loading device and an in-situ transmission electron microscope heating rod, the in-situ mechanical loading device comprises a deformation piece, the deformation piece comprises a substrate, a measurement piece, a conduction piece and at least one pair of suspension beams, the conduction piece comprises a first conduction part and a second conduction part which are sequentially connected in the axial direction, and the first conduction part is connected with the second conduction part. The two cantilevers in each pair of cantilevers are arranged on the two sides of the second conduction part respectively, the second conduction part is connected with the substrate through the cantilevers, the extending direction of each cantilever is perpendicular to the axial direction of the conduction piece, the measuring piece is connected with the substrate, the measuring piece is arranged on the outer side of the first conduction part in a surrounding mode, and a gap is formed between the measuring piece and the first conduction part. A test piece is connected between the measuring sheet and the first conduction part; and one end of the loading sheet is connected with the second conduction part, and the other end of the loading sheet is connected with the substrate. Due to the design of the suspension beam, the load borne by the test piece in the stretching process is the axial stretching load all the time, the measurement precision is improved, and the problem that the in-situ stretching load cannot be centered under the nanoscale is solved.

Description

Technical Field

[0001] The invention relates to the technical field of micro-nanomechanical measurement, and in particular to an in-situ mechanical loading device and an in-situ transmission electron microscope heating rod. Background Art

[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 material mechanical properties of the device are an important basis for its normal operation, it is essential to measure and characterize the mechanical deformation laws at the nanoscale. However, it is very difficult to accurately measure and characterize the mechanical parameters of materials at such a small scale.

[0003] The development of transmission electron microscopy enables people to observe the atomic crystal structure of anatomical materials in detail at the nanoscale or even the atomic scale, providing a good platform for people to enter the nano and atomic world. The transmission electron microscope sample rod is a small experimental platform for observing nanoscale samples. The sample is often placed in a circular area with a diameter of 3 mm at the front end of the sample rod by thinning. The sample rod is inserted into the chamber. The front end of the sample is placed between the pole shoes. The high-energy electron beam penetrates the sample and interacts with the sample. Then the information of the transmitted electrons is collected to obtain the corresponding sample morphology and crystal structure information. Ordinary sample rods can only observe static samples. In order to study the dynamic structure and deformation evolution mechanism of nanomaterials under different environments or working conditions, in-situ transmission loading rods came into being. By introducing the corresponding signal interface inside the loading rod, the corresponding in-situ loading area is formed at the front end of the loading rod sample.

[0004] The in-situ mechanical loading rod is a typical sample rod that applies mechanical loads at the nanoscale. By applying loads to the sample, corresponding in-situ mechanical experiments can be carried out, and the evolution of the sample can be observed at the same time to better understand and reveal the deformation mechanism of the sample. Generally speaking, the in-situ mechanical sample rod usually needs to embed a mechanical drive loading device inside the sample rod, which is generally driven by a piezoelectric drive module group or a stepper motor, and uses a micro-cantilever piezoresistive or capacitive sensor as a load sensor. Due to the complex internal structure of these loading rods, they can generally only tilt or cannot tilt, making it very difficult to achieve mechanical loading experiments with atomic scale resolution, and it is still very difficult to achieve micro-force measurements of nanonewtons and below. Summary of the invention

[0005] The present invention provides an in-situ mechanical loading device and an in-situ transmission electron microscope heating rod, which are used to solve one of the defects in the prior art. The design of the cantilever beam ensures that the load applied to the specimen during the stretching process is always an axial tensile load, and can achieve an ultra-high displacement driving accuracy of less than 1nm, effectively improving the measurement accuracy, and solving the problem that the in-situ tensile load cannot be centered and the load measurement is difficult at the nanometer scale.

[0006] The present invention provides an in-situ mechanical loading device, comprising: A deformation piece, the deformation piece comprises a base piece, a measuring piece, a conducting piece and at least one pair of suspension beams, the conducting piece comprises a first conducting part and a second conducting part sequentially connected along its axial direction, two suspension beams in each pair of suspension beams are respectively arranged on both sides of the second conducting part, the second conducting part is connected to the base piece through the suspension beams, the extension direction of each suspension beam is perpendicular to the axial direction of the conducting piece, the measuring piece is connected to the base piece, the measuring piece is arranged around the outside of the first conducting part and there is a gap between the measuring piece and the first conducting part, and the measuring piece and the first conducting part are suitable for connecting a test piece; A loading sheet, one end of which is connected to the second conducting portion, and the other end of which is connected to the substrate.

[0007] According to an in-situ mechanical loading device provided by the present invention, the measuring piece comprises: a first measuring portion, wherein the extending direction of the first measuring portion is perpendicular to the axial direction of the conductive sheet, a first gap is formed between the first measuring portion and the first conductive portion, and the first measuring portion and the first conductive portion are suitable for connecting a specimen whose tensile and compressive loads are to be measured; The second measuring part has an extending direction perpendicular to the axial direction of the conductive sheet, a second gap is formed between the second measuring part and the first conductive part, and the second measuring part and the first conductive part are suitable for connecting a specimen whose shear and bending loads are to be measured.

[0008] According to an in-situ mechanical loading device provided by the present invention, 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.

[0009] According to an in-situ mechanical loading device provided by the present invention, two ends of the first conducting part protrude symmetrically from two sides of the second conducting part.

[0010] According to an in-situ mechanical loading device provided by the present invention, the measuring piece includes two second measuring parts, the two second measuring parts 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 conducting part respectively.

[0011] According to an in-situ mechanical loading device provided by the present invention, the first gap and the second gap are both rectangular in shape.

[0012] According to an in-situ mechanical loading device provided by the present invention, the deformation sheet includes two pairs of suspension beams, and the loading sheet is arranged between the two pairs of suspension beams.

[0013] According to an in-situ mechanical loading device provided by the present invention, two of the cantilever beams in each pair of the cantilever beams are symmetrically connected to the second conducting part.

[0014] According to an in-situ mechanical loading device provided by the present invention, the loading piece comprises: first metal sheet; The second metal sheet, the first metal sheet and the second metal sheet are arranged in sequence 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, and the second metal sheet and the first metal sheet have different thermal expansion coefficients.

[0015] The present invention also provides an in-situ transmission electron microscope heating rod, comprising the in-situ mechanical loading device as described above.

[0016] The above one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects: The in-situ mechanical loading device of the embodiment of the present invention is mainly composed of a deformation sheet and a loading sheet. The deformation sheet is mainly composed of a substrate, a measuring sheet, a conductive sheet and at least one pair of cantilever beams. The substrate serves as a fixing base for the measuring sheet, the conductive sheet and the cantilever beam. The conductive sheet is divided into a first conductive part and a second conductive part in sequence along its axial direction. One end of the cantilever beam is connected to the second conductive part, and the other end is connected to the substrate, thereby realizing the connection between the conductive sheet and the substrate. The two cantilever beams constitute a pair of cantilever beams. The two cantilever beams are respectively arranged on both sides of the second conductive part, and the extension direction of the cantilever beam is perpendicular to the axial direction of the conductive sheet. There is a certain distance between the measuring sheet and the first conductive part. The two ends of the specimen are respectively connected to the first conductive part and the measuring sheet. One end of the loading sheet is fixed on the substrate, and the other end is connected to the first conductive part.

[0017] Define the axial direction of the conductive sheet as the horizontal direction, and define the direction perpendicular to the axial direction of the conductive sheet as the vertical direction, then the conductive sheet extends horizontally in the horizontal direction, and the suspension beam extends longitudinally in the vertical direction. The loading sheet can be deformed under temperature changes, and the deformation generates a driving force on the conductive sheet, and the driving force can cause the conductive sheet to move in the horizontal and vertical directions. Since the suspension beam constrains the second conductive part in the vertical direction, the conductive sheet cannot be displaced in the vertical direction, that is, under the action of the suspension beam, the driving force generated by the loading sheet can only cause the conductive sheet to move in the horizontal direction, thereby loading the specimen. For the specimen connected between the measuring sheet and the first conductive part, during the tensile or compressive load measurement process, the load on the specimen is always an axial tensile or compressive load, which ensures that the specimen is completely centered during tensile or compressive loading. By observing the deformation of the measuring sheet, the load on the corresponding specimen is calculated.

[0018] The present invention can be applied to in-situ tensile test and mechanical load measurement of nanoscale specimens under transmission electron microscope, and provides a temperature-driven transmission electron microscope in-situ mechanical loading device, which can realize a large range of displacement loading within a relatively low temperature range, and only requires a small amount of temperature load, for example, a temperature increment of about 30°C, to achieve a displacement stroke of more than 2 μm for the conductive sheet, and can also control the temperature to make the loading displacement resolution reach the angstrom level. The design of the cantilever beam ensures that the load on the specimen during the stretching process is always an axial tensile load, and can achieve an ultra-high displacement driving accuracy of less than 1 nm, effectively improving the measurement accuracy, and solving the problem that the in-situ tensile load cannot be centered and the load measurement is difficult at the nanoscale.

[0019] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 is a schematic structural diagram of a deformation piece of an in-situ mechanical loading device provided by an embodiment of the present invention; Figure 2 is a schematic structural diagram of an in-situ mechanical loading device provided by an embodiment of the present invention; Figure 3 is a schematic structural diagram of an in-situ mechanical loading device provided by an embodiment of the present invention loaded with a test piece; Figure 4 The first gap distance of the in-situ mechanical loading device provided by the embodiment of the present invention is 0.87 micrometers in the 30°C no-load test; Figure 5 This is a diagram showing that the first gap distance of the 60°C no-load test of the in-situ mechanical loading device provided by an embodiment of the present invention is 1.13 microns.

[0022] Reference numerals: 100, deformation piece; 110, substrate; 120, measuring piece; 121, first measuring part; 122, second measuring part; 130, conducting piece; 131, first conducting part; 132, second conducting part; 140, cantilever beam; 151, first gap; 152, second gap; 153, first hollow part; 154, second hollow part; 155, third hollow part; 156, fourth hollow part; 200, loading sheet; 210, first metal sheet; 220, second metal sheet; 230, high temperature glue; 310, first test piece; 320, second test piece. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and 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 devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations on the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0025] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0026] In the embodiments of the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0027] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0028] like Figure 1 , Figure 2 and Figure 3As shown, the in-situ mechanical loading device provided by the embodiment of the present invention includes a deformation piece 100 and a loading piece 200. The deformation piece 100 includes a substrate 110, a measuring piece 120, a conducting piece 130 and at least one pair of cantilever beams 140. The conducting piece 130 includes a first conducting part 131 and a second conducting part 132 connected in sequence along its axial direction. Two cantilever beams 140 in each pair of cantilever beams 140 are respectively arranged on both sides of the second conducting part 132. The second conducting part 132 is connected to the substrate 110 through the cantilever beams 140. The extension direction of each cantilever beam 140 is perpendicular to the axial direction of the conducting piece 130. The measuring piece 120 is connected to the substrate 110. The measuring piece 120 is arranged around the outside of the first conducting part 131 and has a gap with the first conducting part 131. The measuring piece 120 and the first conducting part 131 are suitable for connecting a specimen. One end of the loading piece 200 is connected to the second conducting part 132, and the other end is connected to the substrate 110.

[0029] The in-situ mechanical loading device of the embodiment of the present invention is mainly composed of a deformation sheet 100 and a loading sheet 200. The deformation sheet 100 is mainly composed of a substrate 110, a measuring sheet 120, a conducting sheet 130 and at least one pair of cantilever beams 140. The substrate 110 serves as a fixed base for the measuring sheet 120, the conducting sheet 130 and the cantilever beam 140. The conducting sheet 130 is divided into a first conducting part 131 and a second conducting part 132 in sequence along its axial direction. One end of the cantilever beam 140 is connected to the second conducting part 132, and the other end is connected to the substrate 110. , thereby realizing the connection between the conductive sheet 130 and the substrate 110, the two suspension beams 140 constitute a pair of suspension beams 140, the two suspension beams 140 are respectively arranged on both sides of the second conductive part 132, and the extension direction of the suspension beams 140 is perpendicular to the axial direction of the conductive sheet 130, there is a certain distance between the measuring sheet 120 and the first conductive part 131, the two ends of the specimen are respectively connected to the first conductive part 131 and the measuring sheet 120, one end of the loading sheet 200 is fixed on the substrate 110, and the other end is connected to the first conductive part 131.

[0030] The axial direction of the conductive sheet 130 is defined as the horizontal direction, and the direction perpendicular to the axial direction of the conductive sheet 130 is defined as the vertical direction. Then, the conductive sheet 130 extends horizontally in the horizontal direction, and the suspension beam 140 extends longitudinally in the vertical direction. The loading sheet 200 can be deformed under temperature changes, and a driving force is generated on the conductive sheet 130 through the deformation. The driving force can make the conductive sheet 130 move in the horizontal and vertical directions. Since the suspension beam 140 constrains the second conductive part 132 in the vertical direction, the conductive sheet 130 cannot be displaced in the vertical direction. That is, under the action of the suspension beam 140, the driving force generated by the loading sheet 200 can only make the conductive sheet 130 move in the horizontal direction, thereby loading the specimen. For the test piece connected between the measuring piece 120 and the first conducting part 131, during the tensile or compressive load measurement process, the load applied to the test piece is always an axial tensile or compressive load, thereby ensuring that the test piece is completely aligned during tensile or compressive loading. The load applied to the corresponding test piece can be calculated by observing the deformation of the measuring piece 120.

[0031] The present invention can be applied to in-situ tensile test and mechanical load measurement of nanoscale specimens under transmission electron microscope, and provides a temperature-driven transmission electron microscope in-situ mechanical loading device, which can realize a large range of displacement loading within a relatively low temperature range, and only requires a small amount of temperature load, for example, a temperature increment of about 30°C, to achieve a displacement stroke of more than 2 μm for the conductive sheet 130, and can also control the temperature to make the loading displacement resolution reach the angstrom level. The design of the cantilever beam 140 ensures that the load on the specimen during the stretching process is always an axial tensile load, and can achieve an ultra-high displacement driving accuracy of less than 1 nm, effectively improving the measurement accuracy, and solving the problem that the in-situ tensile load cannot be centered and the load measurement is difficult at the nanoscale.

[0032] In this embodiment, the substrate 110, the measuring sheet 120, the conducting sheet 130 and at least one pair of suspension beams 140 are all obtained on a metal sheet by a metal etching method. After the measuring sheet 120, the conducting sheet 130 and at least one pair of suspension beams 140 are etched on the metal sheet, the remaining part 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, tungsten, etc. The size of each suspension 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 size of the measuring sheet 120 is 300 μm in length, 10 μm in width, and 10 μm in thickness. The preliminary pattern shape with a length of 300 μm, a width of 20 μm, and a thickness of 30 μm is first obtained by metal etching, and then the structure of the measuring sheet 120 is further etched by a FIB (focused ion beam) etching refinement method.

[0033] According to an embodiment provided by the present invention, the measuring piece 120 includes a first measuring part 121 and a second measuring part 122, the extension direction of the first measuring part 121 is perpendicular to the axial direction of the conducting piece 130, a first gap 151 is formed between the first measuring part 121 and the first conducting part 131, and the first measuring part 121 and the first conducting part 131 are suitable for connecting a specimen to be measured for tensile and compressive loads; the extension direction of the second measuring part 122 is perpendicular to the axial direction of the conducting piece 130, a second gap 152 is formed between the second measuring part 122 and the first conducting part 131, and the second measuring part 122 and the first conducting part 131 are suitable for connecting a specimen to be measured for shear and bending loads.

[0034] In this embodiment, the measuring piece 120 is mainly composed of a first measuring part 121 and a second measuring part 122. The axial direction of the conductive piece 130 is defined as a horizontal direction, and the direction perpendicular to the axial direction of the conductive piece 130 is defined as a 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.

[0035] 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, and the axial load generated by the conducting sheet 130 is in the horizontal direction, forming a tensile or compressive load for 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 an in-situ tensile and compressive mechanical loading mode.

[0036] When the second specimen 320 is connected between the second measuring part 122 and the first conducting part 131, the second specimen 320 is fixed in the vertical direction, and the axial load generated by the conducting sheet 130 is in the horizontal direction. The direction of the axial load is perpendicular to the extension direction of the second specimen 320, thereby 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 an in-situ shear and bending mechanical loading mode.

[0037] The present invention can simply but accurately provide a variety of mechanical loading schemes such as stretching, compression, shearing, bending, etc., and can be flexibly applied to the in-situ mechanical loading measurement and real-time characterization of various nanoscale materials under transmission electron microscopy, which is conducive to the diversification of loading methods and is of great significance for future high-throughput in-situ transmission nanomechanical characterization.

[0038] In this embodiment, the first hollow part 153, the second hollow part 154, the third hollow part 155 and the fourth hollow part 156 are formed on the metal sheet by metal etching, that is, the substrate 110 and the measuring sheet 120, the conducting sheet 130 and the suspension beam 140 are separated by the hollow parts. The first hollow part 153 and the second hollow part 154 together enclose the first measuring part 121, the second hollow part 154 encloses the first conducting part 131, part of the second conducting part 132 and the second measuring part 122, the third hollow part 155 and the second hollow part 154 together enclose a pair of suspension beams 140, the third hollow part 155 encloses part of the second conducting part 132, the third hollow part 155 and the fourth hollow part 156 together enclose another pair of suspension beams 140, and the fourth hollow part 156 encloses part of the second conducting part 132. Among them, the first gap 151 and the second gap 152 are both part of the second hollow part 154.

[0039] According to an embodiment provided by 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, then 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 is equivalent to the first conductive portion 131 extending and protruding from the second conductive portion 132 in its width direction.

[0040] The first conducting part 131 is connected to one end of the specimen, and the first conducting part 131 can protrude from the second conducting part 132 in the vertical direction, further increasing the available area for connection and fixation with the specimen, while providing more positions and spaces for the first measuring part 121 and the second measuring part 122 to be connected with the first conducting part 131 through the specimen to avoid mutual influence.

[0041] According to an embodiment provided by the present invention, two ends of the first conducting portion 131 symmetrically protrude from two sides of the second conducting portion 132. In this embodiment, the second conducting portion 132 is in the shape of a rectangular strip and extends in the horizontal direction, and the first conducting portion 131 is also in the shape of a rectangular strip and extends in the vertical direction. One end of the second conducting portion 132 is connected to the middle of the first conducting portion 131, so that the first conducting portion 131 and the second conducting portion 132 are connected to form an inverted T-shaped conducting sheet 130.

[0042] The two ends of the first conducting part 131 protrude from the second conducting part 132 in the width direction of the conducting sheet 130, forming a double-sided protrusion in the width direction of the second conducting part 132, and the two ends have the same extension length in the width direction, forming a symmetrical T-shaped structure, further increasing the available area for connection and fixation with the test piece, and providing more positions and spaces for the first measuring part 121 and the second measuring part 122 to connect with the first conducting part 131 through the test piece. In addition, the symmetrical conducting sheet 130 can be more stable and reliable in load transmission.

[0043] 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.

[0044] According to an embodiment provided by the present invention, the measuring piece 120 includes two second measuring parts 122, the two second measuring parts 122 are symmetrically connected to the two ends of the first measuring part 121, and the two second measuring parts 122 correspond to the two ends of the first conducting part 131. In this embodiment, the measuring piece 120 is mainly composed of a first measuring part 121 and two second measuring parts 122, the first measuring part 121 extends in the vertical direction, the second measuring part 122 extends in the vertical direction, and the two ends of the first measuring part 121 are respectively connected to the substrate 110, the first measuring part 121 and the first conducting part 131 are opposite and parallel to each other, and the ends of the two second measuring parts 122 are both connected to the substrate 110, that is, the two second measuring parts 122 are respectively arranged in the vertical extension direction of the first conducting part 131, and respectively correspond to the ends of the first conducting part 131, and the range of the first measuring part 121 corresponds to the entire first conducting part 131 in the vertical direction.

[0045] The combined structure of the first measuring part 121 and the second measuring part 122 surrounds the first conducting part 131 on three sides, further increasing the available area for connection and fixation with the test piece, and providing more positions and spaces for the first measuring part 121 and the second measuring part 122 to connect with the first conducting part 131 through the test piece. When the first conducting part 131 extends symmetrically along the vertical direction at the end of the second conducting part 132, the two second measuring parts 122 are also symmetrically arranged relative to the first measuring part 121, forming a symmetrical structure of the measuring piece 120, which can be more stable and reliable in load transmission.

[0046] According to an embodiment provided by the present invention, the shapes of the first gap 151 and the second gap 152 are both rectangular. In this embodiment, the edge adjacent to the first measuring portion 121 and the first conducting portion 131 is designed to be a straight line, thereby forming a rectangular first gap 151, and the edge adjacent to the second measuring portion 122 and the first conducting portion 131 is designed to be a straight line, thereby forming a rectangular second gap 152.

[0047] After the load is applied, the deformation of the measuring piece 120 caused by the specimen load can directly affect the shapes 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, and making the displacement of the measuring piece 120 more intuitive and clear, which is convenient for observation and measurement, thereby improving the measurement accuracy.

[0048] According to an embodiment provided by the present invention, the deformation sheet 100 includes two pairs of suspension beams 140, and the loading sheet 200 is arranged between the two pairs of suspension beams 140. In this embodiment, the deformation sheet 100 is mainly composed of a substrate 110, a measuring sheet 120, a conductive sheet 130 and two pairs of suspension beams 140. The two pairs of suspension beams 140 are connected to the second conductive part 132, and multiple positions of the second conductive part 132 are provided with connections with the substrate 110, so that the restraining force of the suspension beams 140 on the conductive sheet 130 is more evenly distributed on the second conductive part 132, and the restraining effect is more significant. The loading sheet 200 is arranged between the two pairs of suspension beams 140, and the driving force of the loading sheet 200 on the conductive sheet 130 can be restrained in front and behind the loading sheet 200 in the horizontal direction, further improving the restraining effect of the suspension beams 140 on the movement of the conductive sheet 130 in the vertical direction.

[0049] In this embodiment, two pairs of suspension beams 140 are evenly distributed on the second conducting part 132 to ensure that the restraining force on the second conducting part 132 is evenly distributed. In other embodiments, the number of pairs of suspension beams 140 is set according to actual needs, but it should not be too many. Too many suspension beams 140 will not only restrain the displacement of the conducting piece 130 in the vertical direction, but may also have a restraining effect on the displacement of the conducting piece 130 in the horizontal direction, thereby affecting the load applied by the conducting piece 130 to the specimen.

[0050] According to an embodiment provided by the present invention, two suspension beams 140 in each pair of suspension beams 140 are symmetrically connected to the second conductive portion 132. In this embodiment, each pair of suspension beams 140 is composed of two suspension beams 140 arranged opposite to each other on both sides of the second conductive portion 132. In order to ensure the balance of the connection force of the conductive sheet 130 and the stability of the connection of the suspension beams 140, the suspension beams 140 are arranged in a symmetrical form.

[0051] 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 be composed of two non-opposite suspension beams 140, and there is 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, suspension beams 140 are formed that are spaced apart on both sides of the second conductive part 132.

[0052] According to an embodiment provided by the present invention, the loading sheet 200 includes a first metal sheet 210 and a second metal sheet 220, the first metal sheet 210 and the second metal sheet 220 are arranged in sequence along the axial direction of the conductive sheet 130, and the second metal sheet 220 and the first metal sheet 210 are connected in parallel on the same plane, and the second metal sheet 220 and the first metal sheet 210 have different thermal expansion coefficients.

[0053] In this embodiment, the loading sheet 200 is composed of a first metal sheet 210 and a second metal sheet 220 to form a bimetallic structure. The first metal sheet 210 and the second metal sheet 220 are connected in parallel in the same plane. Since the thermal expansion coefficients of the second metal sheet 220 and the first metal sheet 210 are different, the thermal deformation of the materials is inconsistent. Therefore, when the temperature is increased, the deformation degrees of the first metal sheet 210 and the second metal sheet 220 are different. Different deformation degrees will cause the loading sheet 200 to bend toward the side where the first metal sheet 210 or the side where the second metal sheet 220 is located. The end of the loading sheet 200 connected to the substrate 110 remains fixed, and the end connected to the second conductive part 132 is bent and deflected, thereby generating a driving force on the conductive sheet 130, and then applying a load to the specimen.

[0054] It is defined that the side where the first metal sheet 210 is located is close to the first conducting part 131, and the side where the second metal sheet 220 is located is far away from the first conducting part 131. When the loading sheet 200 bends toward the side where the first metal sheet 210 is located, the conducting sheet 130 is driven to be close to the first measuring part 121, and a compressive load is applied to the first specimen 310. When the loading sheet 200 bends toward the side where the second metal sheet 220 is located, the conducting sheet 130 is driven to be far away from the first measuring part 121, and a tensile load is applied to the first specimen 310. When the temperature change cannot cause the loading sheet 200 to deform, the relative position of the first metal sheet 210 and the second metal sheet 220 can be changed to make the loading sheet 200 bend and deflect in a predetermined direction.

[0055] In this embodiment, the size of the loading sheet 200 is 150 μm thick, 1.2 mm long, and 200 μm wide. First, the corresponding bimetallic sheet is prepared, and then the bimetallic sheet is cut into a long strip structure with a thickness of about 500 μm, a length of 30 mm, and a width of 200 μm by wire cutting. The long strip structure is cut into a short rod-shaped sample with a length of 2 mm, a width of 200 μm, and a thickness of 500 μm by high-strength scissors. Finally, the short rod-shaped sample is glued to a glass sheet, and manually polished on metallographic sandpaper to finally form the loading sheet 200. Then, the self-ground loading sheet 200 is glued to the deformation sheet 100 through high-temperature glue 230. After high-temperature curing at 100°C for 1 hour, the loading sheet 200 and the deformation sheet 100 can be firmly bonded to form an in-situ mechanical loading device of the present invention.

[0056] The present invention can adjust 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, so that the device can achieve stable and accurate in-situ mechanical loading and load measurement, forming a complete set of in-situ mechanical loading quantitative design scheme. In summary, the design scheme is ingenious, the manufacturing procedure is simple, and it can achieve very high-precision mechanical loading and load measurement, and can achieve in-situ TEM (transmission electron microscope) mechanical characterization and load measurement of a large number of nanomaterials, especially for the recently developed low-dimensional materials. It is an effective in-situ mechanical loading device. The present invention forms the corresponding loading plate 200 through laser processing and etching combined with manual grinding, which can achieve in-situ mechanical load measurement and in-situ atomic scale observation of various materials at the nanoscale, which is of great significance to the development of transmission electron microscope in-situ technology.

[0057] After the in-situ mechanical loading device is made, the test piece is made. For general metal materials, the FIB processing method can be used for sample preparation. First, the large block sample is placed in the FIB electron microscope room, and the corresponding micron-level plate-like pattern is formed by ion beam milling. Then the plate-like sample is extracted by a nanomanipulator and fixed to the first gap 151 or the second gap 152 on both sides of the in-situ mechanical loading device. After the two ends of the test piece are fixed by FIB ion beam assisted deposition, the area corresponding to the first gap 151 or the second gap 152 on the test piece is thinned by the FIB ion beam. First, a large beam is used for thinning. When the thickness of the thinned area drops to about 150 nanometers, a small beam is used for thinning until the thickness of the thinned area reaches about 60 nanometers. Then, the corresponding dog-bone-shaped test piece is processed by FIB pattern etching. For two-dimensional materials, the material can also be transferred to the corresponding position by wet transfer, and then cleaned with organic solvents such as acetone.

[0058] 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 and the in-situ mechanical loading device described above can be referred to each other.

[0059] An embodiment of the present invention further provides an in-situ transmission electron microscope heating rod, comprising an in-situ mechanical loading device as described in the above embodiment.

[0060] After the specimen is prepared, the in-situ mechanical loading device and the specimen are placed together in the in-situ transmission electron microscope heating rod, 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 prepared in-situ mechanical loading device with the specimen is placed in the crucible, and the screws are tightened to complete the sample installation operation. When conducting in-situ experiments under the transmission electron microscope, the temperature of the sample area can be accurately adjusted through the temperature control system of the heating rod. The temperature adjustment range can reach an accuracy of 0.1°C. The speed of temperature rise can be adjusted according to the test sample requirements.

[0061] like Figure 4 and Figure 5 As shown, the unloaded in-situ mechanical loading device was tested. When the temperature increment was 30°C, the width of the first gap 151 was 0.87μm; when the temperature increment was 60°C, the width of the first gap 151 was 1.13μm. It can be found that under the drive of the temperature load, the in-situ mechanical loading device can produce a driving displacement of 260 nanometers in length, which is completely sufficient for the specimen at the nanoscale, and the ambient temperature only increased by 30°C, which minimized the influence of temperature on the mechanical properties of the specimen. According to the loading step of 0.1°C, the displacement driving accuracy is 0.86 nanometers with high sensitivity.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions 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 piece, the deformation piece comprises a base piece, a measuring piece, a conducting piece and at least one pair of suspension beams, the conducting piece comprises a first conducting part and a second conducting part sequentially connected along its axial direction, two suspension beams in each pair of suspension beams are respectively arranged on both sides of the second conducting part, the second conducting part is connected to the base piece through the suspension beams, the extension direction of each suspension beam is perpendicular to the axial direction of the conducting piece, the measuring piece is connected to the base piece, the measuring piece is arranged around the outside of the first conducting part and there is a gap between the measuring piece and the first conducting part, and the measuring piece and the first conducting part are suitable for connecting a test piece; A loading sheet, one end of which is connected to the second conducting portion, and the other end of which is connected to the substrate.

2. The in-situ mechanical loading device according to claim 1, characterized in that: The measuring piece comprises: a first measuring portion, wherein the extending direction of the first measuring portion is perpendicular to the axial direction of the conductive sheet, a first gap is formed between the first measuring portion and the first conductive portion, and the first measuring portion and the first conductive portion are suitable for connecting a specimen whose tensile and compressive loads are to be measured; The second measuring part has an extending direction perpendicular to the axial direction of the conductive sheet, a second gap is formed between the second measuring part and the first conductive part, and the second measuring part and the first conductive part are suitable for connecting a specimen whose shear and bending loads are to be measured.

3. The in-situ mechanical loading device according to claim 2, characterized in that: A width of the first conductive portion along an axial direction perpendicular to the conductive sheet is greater than a width of the second conductive portion along the axial direction perpendicular to the conductive sheet.

4. The in-situ mechanical loading device according to claim 2, characterized in that: Two ends of the first conducting portion symmetrically protrude from two sides of the second conducting portion.

5. The in-situ mechanical loading device according to claim 4, characterized in that: The measuring piece includes two second measuring parts, the two second measuring parts are symmetrically connected to two ends of the first measuring part, and the two second measuring parts correspond to two ends of the first conducting part respectively.

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

7. The in-situ mechanical loading device according to claim 1, characterized in that: The deformation sheet includes two pairs of suspension beams, and the loading sheet is arranged between the two pairs of suspension beams.

8. The in-situ mechanical loading device according to claim 7, characterized in that: The two suspension beams in each pair of the suspension beams are symmetrically connected to the second conducting portion.

9. The in-situ mechanical loading device according to any one of claims 1 to 8, characterized in that: The loading sheet comprises: first metal sheet; The second metal sheet, the first metal sheet and the second metal sheet are arranged in sequence 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, and the second metal sheet and the first metal sheet have different thermal expansion coefficients.

10. An in-situ transmission electron microscope heating rod, characterized in that: It comprises the in-situ mechanical loading device as described in any one of claims 1 to 9.

Images