Compression testing apparatus

Abstract

To provide a compression testing device capable of applying a minute load without being limited by the size of a measurement area.SOLUTION: The compression test device 1 includes a load applying part 20 for applying a load to a sample, a load light-emitting part 30 including a stress luminescent material that emits light according to the load, and a light emission detecting part 60 for detecting the light emission, wherein the load light-emitting part includes a contact part 31 having a contact surface that comes into contact with the sample, and a light-emitting source part 35 provided on the opposite side of the contact surface of the contact part and including the stress luminescent material that emits light according to the load applied to the contact part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a compression testing device that can apply a load to a target object and examine the characteristics of the target object from the relationship between the magnitude of the applied force and the amount of deformation, and in particular to a compression testing device that can examine the characteristics of a target object by applying a minute load (e.g., 100 nN or less) to an area exceeding a predetermined area (e.g., a diameter of 50 μm or more). [Background technology]

[0002] Conventionally, there have been compression test devices that apply a load to a sample (target object) and can examine the characteristics of the target object from the relationship between the magnitude of the applied force and the amount of deformation. Known examples of such compression test devices include a compression test device that uses an atomic force microscope (AFM) (see, for example, Patent Document 1) and a nanoindentation device (nanoindenter). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-117110 Summary of the Invention [Problem to be solved by the invention]

[0004] However, AFM compression testing devices rely on the principle of detecting the atomic force acting between an AFM probe attached to the tip of a cantilever and a sample by measuring the deflection of the cantilever when the probe is brought into contact with the sample surface with a small force. Although they can apply minute loads with sensitivity in the piconewton to nanonewton range, the horizontal length of the target object that can be measured is limited by the size of the AFM probe tip, which is a maximum of approximately 50 μm (50 μm or less). Furthermore, because the size of the AFM probe tip is proportional to its weight and affects the amount of cantilever deflection, AFM compression testing devices can only measure the load acting on a small area of ​​the target object (maximum diameter of 50 μm). Furthermore, to examine large-area samples using AFM compression testing devices, the typical method is to orthogonally scan the AFM probe across the horizontal plane of the target object, which is time-consuming.

[0005] On the other hand, nanoindenters are devices that evaluate hardness from load and indentation depth, and can measure loads with a sensitivity of 100 nanonewtons (greater than 100 nN). However, like compression testing devices using AFMs, they are limited by the size of the nanoindenter's indenter tip, and the maximum horizontal length of the target object that can be measured is approximately 50 μm (50 μm or less). In other words, nanoindenters also have the problem of only being able to measure the load applied to a very small area of ​​the target object (maximum diameter 50 μm). Furthermore, for the same reasons as AFMs, examining large-area samples using a nanoindenter also takes a long time.

[0006] However, as described in Patent Publication No. 2021-191238, for example, there is a method for evaluating the invasive ability of cancer cells by applying an external force to them and measuring the discharge of chloride ions from the cancer cells. However, when early measurement (diagnosis) is required, such as during surgery, a compression testing device is required that can apply loads with a sensitivity of tens of nanonewtons (tens of nN) to large areas of cancer tissue, for example, with sides of 1 mm or more (1 mm square or more).

[0007] In view of the above circumstances, an object of the present invention is to provide a compression testing device that is capable of applying a minute load without being limited by the size of the measurement area.

[0008] These problems (issues) do not preclude the existence of other problems. Furthermore, each aspect of the present invention described below does not necessarily solve all of these problems (issues). Furthermore, other problems (issues) may be identified from the description of the specification, drawings, or claims. [Means for solving the problem]

[0009] The inventors of the present invention have continued to conduct extensive research into the above-mentioned problems and have come up with the following revolutionary compression testing device.

[0010] A first aspect of the present invention for solving the above problem is a compression testing device comprising a load application section that applies a load to a sample, a load light-emitting section that contains a mechanoluminescent material that emits light in response to the load, and an emission detection section that detects the emission, wherein the load light-emitting section comprises a contact section having a contact surface that contacts the sample, and a light-emitting source section that is provided on the opposite side of the contact surface of the contact section and contains a mechanoluminescent material that emits light in response to the load applied to the contact section.

[0011] According to the first aspect, it is possible to provide a compression testing device that is not limited by the size of the measurement area and that can apply a minute load.

[0012] A second aspect of the present invention is a compression testing device according to the first aspect, characterized in that the load light-emitting unit comprises a hollow frame body, a light-emitting source unit that is arranged within the frame body in a state connected to the contact portion and contains a stress-luminescent material, and a regulating unit that is arranged within the frame body and regulates the light-emitting source unit from moving within the frame body when the contact portion comes into contact with the sample.

[0013] According to the second aspect, it is possible to extract only the light emitted from the mechanoluminescent material contained in the light source unit without receiving any external light, thereby providing a compression testing device that can apply a minute load more accurately.

[0014] A third aspect of the present invention is the compression testing device according to the second aspect, characterized in that the light-emitting source unit has a plurality of columnar parts, and the columnar parts contain a stress-luminescent material on at least a portion of their surface or interior.

[0015] According to the third aspect, the columnar section bends or buckles to emit light even when a small load is applied, thereby providing a compression testing device that can apply even smaller loads. Furthermore, according to the third aspect, the material constituting the columnar section can be freely selected, thereby providing a compression testing device having a columnar section that is optimal for the sample.

[0016] A fourth aspect of the present invention is the compression testing device according to the third aspect, wherein the area of ​​one end face of the columnar portion is smaller than the area of ​​the other end face.

[0017] According to the fourth aspect, the light emitting element is more likely to bend or buckle than a columnar element having the same area on one end face and the same area on the other end face, and as a result, it can emit light with sufficient intensity even when a small load is applied.

[0018] A fifth aspect of the present invention is the compression testing device according to the third or fourth aspect, characterized in that the plurality of pillars are uniformly provided at predetermined intervals.

[0019] According to the fifth aspect, since the light is emitted uniformly in response to the same load, it is possible to provide a compression testing device that can apply a minute load more accurately.

[0020] A sixth aspect of the present invention resides in the compression testing device according to the first aspect, characterized in that the sample is cancer tissue.

[0021] According to the sixth aspect, the invasive potential of cancer cells contained in cancer tissue can be evaluated more quickly. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a schematic diagram of a compression test device according to the first embodiment. [Figure 2] FIG. 2 is an enlarged schematic view of the loaded light-emitting portion of the first embodiment. [Figure 3] FIG. 3 is a schematic diagram showing an example of the operation of the compression testing device of the first embodiment. [Figure 4] FIG. 4 is a photograph showing the columnar part of the example. [Figure 5] FIG. 5 is a graph showing the relationship between load and luminescence intensity in the example. [Figure 6] FIG. 6 is a bar graph showing the emission intensity for repeated operations in the example. DETAILED DESCRIPTION OF THE INVENTION

[0023] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A compression testing device according to an embodiment of the present invention will be described below with reference to the accompanying drawings. However, the present invention is not limited to the following embodiments.

[0024] (Embodiment 1) 1 is a schematic diagram of a compression testing device according to this embodiment. As shown in this figure, the compression testing device 1 is composed of a base 2, a main body 10, a load applying unit 20, a load light emitting unit 30, a control unit 40, a transmission unit 50, a light emission detecting unit 60, and a sample stage unit 70.

[0025] The base 2 is not particularly limited as long as it has a horizontal upper surface and can support the main body 10 and the sample stage 70, and may be, for example, a concrete or metal plate.

[0026] The shape and material of the main body 10 are not particularly limited as long as it can hold the load applying portion 20 and the load light emitting portion 30 .

[0027] The load applying unit 20 has a cantilever shape, with one end attached to one side of the main body 10 and movable up and down. The up and down movement can be achieved by a stepping motor or the like provided inside the load applying unit 20. The shape of the load applying unit 20 is not particularly limited as long as it can hold the light-emitting unit 30; for example, when a twin-column system is used, both ends of the load applying unit 20 may be fixed.

[0028] The load light-emitting unit 30, which will be described in detail later, is cylindrical and is attached to the other end of the load applying unit 20 so that its axis is vertical. A contact unit 31 is provided at the lower end of the load light-emitting unit 30, and by moving the load applying unit 20 up and down, the contact unit 31 can be brought into contact with a sample (not shown) and a load can be applied to the sample.

[0029] The location of the control unit 40 is not particularly limited, but it is connected to the load application unit 20 and the sample stage unit 70 (not shown), as well as to the emission detection unit 60. As will be described later, the control unit 40 is configured to control the vertical movement of the load application unit 20, control the horizontal movement of the sample stage unit 70, and measure (process) the emission distribution and emission intensity of light detected by the emission detection unit 60. The control unit 40 may be connected only to the load application unit 20 and the emission detection unit 60. In this case, the sample stage unit 70 has a function to manually adjust the horizontal movement control. The control unit 40 is not particularly limited as long as it has such a function, but a personal computer, for example, can be used.

[0030] The transmission unit 50 has one end connected to the upper end of the load light-emitting unit 30 and the other end connected to the light emission detection unit 60, and as will be described later, can transmit the light emitted from the load light-emitting unit 30 to the light emission detection unit 60. The transmission unit 50 may be a commercially available optical fiber or the like.

[0031] The light emission detection unit 60 is not particularly limited as long as it can detect the light transmitted by the transmission unit 50. Examples of the light emission detection unit 60 include commercially available optical sensors.

[0032] The sample stage 70 is not particularly limited as long as it can move the placed sample in the horizontal direction (left and right in FIG. 1 or vertical to the paper surface). Examples of the sample stage 70 include a stage with a movement function driven by a stepping motor or the like.

[0033] Next, the load light-emitting unit 30 will be described in detail. Fig. 2 is an enlarged schematic view of the load light-emitting unit 30. As shown in this figure, the load light-emitting unit 30 is composed of a cylindrical frame 32, a contact unit 31 arranged therein, a light source unit 35, and an optical path unit 37.

[0034] A circular opening 321 is formed in the lower part of the frame 32, and an annular restricting portion 322 that protrudes inward from the frame 32 is formed above the opening 321. As will be described later, the shape and structure of the restricting portion 322 are not particularly limited as long as it can restrict the movement of the light source portion 35. In addition, the frame 32 is not particularly limited as long as it has such a shape, and its material may be plastic, metal, or the like.

[0035] The contact part 31 has a generally cylindrical shape with a generally T-shaped cross section. A part of the lower part of the contact part 31 is disposed so as to protrude outward from the opening 321 of the frame body 32, and this protruding part is adapted to come into contact with the measurement sample. Meanwhile, the upper part of the contact part 31 is connected to the light source part 35. The contact part 31 is not particularly limited as long as it has such a shape, and its material may be plastic, metal, or the like.

[0036] The light-emitting source 35 is disposed so as to be sandwiched between the upper part of the contact portion 31 and the restricting portion 322 of the frame body 32, and even if it tries to move upward, it is prevented from doing so by the restricting portion 322. As a result, the load on the contact portion 31 is directly applied to the light-emitting source 35, and the light is emitted in response to that load. Details of the light-emitting source 35 will be described later.

[0037] The optical path section 37 is not particularly limited as long as it can transmit the light emitted from the light source section 35 to the transmission section 50. The optical path section 37 may be a commercially available optical fiber or a component composed of a core and cladding of the transmission section (optical fiber) 50 with the coating removed. The distance between the light source section 35 and the optical path section 37 is not particularly limited as long as the light emitted from the light source section 35 can be efficiently transmitted to the optical path section 37. The contact section 31 (excluding a portion of the lower portion), the light source section 35, and the optical path section 37 are disposed inside the frame 32. Therefore, external light is prevented from entering the light source section 35 and the optical path section 37, and only the light emitted from the light source section 35 can be guided to the optical path section 37. In other words, only the light emitted from the light source section 35 can be transmitted to the light emission detection section 60 via the transmission section 50. Incidentally, when external light enters the light source section 35, the mechanoluminescent material described below is excited. As a result, the stress-stimulated luminescent material emits light even when no load is applied, making it impossible to measure the load accurately.

[0038] Next, the light-emitting source unit 35 will be described in detail. As shown in Fig. 2, the light-emitting source unit 35 is composed of a disk-shaped lower plate 351 that contacts the upper surface of the contact portion 31, a disk-shaped upper plate 353 whose edge contacts the restricting portion 322, and a plurality of columnar portions 352 arranged between them.

[0039] Here, the upper plate 353 and the lower plate 351 are arranged so as to be in contact with the columnar portion 352 (so as to have a length equal to or nearly equal to the vertical length of the columnar portion 352).

[0040] The lower plate 351 is not particularly limited and may be made of plastic, metal, glass, single crystal, ceramics, etc., but is preferably provided with a reflective layer on its upper surface so as to reflect upward the light emitted from the columnar portion 352, as will be described later. The reflective layer is not particularly limited as long as it can reflect the light emitted from the columnar portion 352, and examples thereof include a lower plate 351 having a mirror-finished surface layer, a metal vapor deposition film, a metal sputtering film, etc.

[0041] On the other hand, the upper plate 353 is not particularly limited as long as it can transmit light emitted from the columnar portion 352 and light reflected by the lower plate 351, as will be described later. Examples of materials for the upper plate 353 include quartz glass, borosilicate glass, crystallized glass, single crystal zirconia, polycarbonate resin, and acrylic resin.

[0042] The columnar section 352 is not particularly limited as long as it contains a stress-stimulated luminescent material at least on its surface or in part of its interior and emits light in response to deformation (including elastic deformation and plastic deformation) caused by a load applied to the lower plate 351 via the contact section 31 when a sample comes into contact with the contact section 31. The stress-stimulated luminescent material may be disposed on the entire surface of the columnar section 352, or only on a portion of it. The stress-stimulated luminescent material may also be disposed on all or part of the interior of the columnar section 352. In this case, it goes without saying that the material constituting the columnar section 352 other than the stress-stimulated luminescent material is preferably one that does not absorb the light (electromagnetic waves) emitted from the stress-stimulated luminescent material (e.g., one that transmits 80% to 100% of the light emitted from the stress-stimulated luminescent material). Furthermore, the columnar section 352 may be formed of a stress-stimulated luminescent material.

[0043] The shape of the columnar portion 352 is not particularly limited as long as it extends in a direction approximately perpendicular to the surfaces of the upper plate 353 and the lower plate 351. For example, the horizontal cross-sectional shape (the cross-sectional shape when the columnar portion 352 is cut in the horizontal direction (perpendicular to the axis of the columnar portion 352)) is not particularly limited, and may be a circle, ellipse, triangle, rectangle, hexagon, hollow, or irregular shape. Furthermore, the axial cross-sectional shape of the columnar portion 352 (the cross-sectional shape when the columnar portion 352 is cut in the vertical direction (the axial direction of the columnar portion 352)) is also not particularly limited, and may be any shape such as a triangle, square, rectangle, trapezoid, hollow, or irregular shape. Note that "approximately vertical direction" refers to a direction in the range of -20 degrees to 20 degrees (70 degrees to 110 degrees) relative to the vertical direction (90 degrees) of the surfaces of the upper plate 353 and the lower plate 351, and preferably refers to a direction in the range of -10 degrees to 10 degrees (80 degrees to 100 degrees).

[0044] Here, the shape of the columnar portion 352 is preferably one in which the area of ​​one end face is smaller than the area of ​​the other end face. A columnar portion 352 having such a shape is more likely to bend or buckle than a columnar portion in which the area of ​​one end face is equal to the area of ​​the other end face. As a result, the columnar portion 352 can emit light with sufficient intensity even when a small load is applied. A particularly preferable shape of the columnar portion 352 is a cone, which can emit light with sufficient intensity even when a smaller load is applied. Note that the columnar portion in FIG. 2 has a cone shape in which the area of ​​the bottom face of the columnar portion 352 is larger than that of the top face, but it goes without saying that a similar effect can be obtained even if the area of ​​the bottom face of the columnar portion 352 is a cone shape in which the area of ​​the top face of the columnar portion 352 is smaller than that of the bottom face (a shape that is upside down from the columnar portion 352 in FIG. 2).

[0045] Furthermore, the height h of the columnar portion 352 is not particularly limited, but is preferably in the range of 100 nm to 1 mm, since it can emit light with high intensity when the load applied to the columnar portion 352 is applied. A range of 1 μm to 700 μm is more preferable, since it can emit light with even higher intensity when the load applied to the columnar portion 352 is applied. A range of 50 μm to 500 μm is particularly preferable, since it can emit light with even higher intensity when the load applied to the columnar portion 352 is applied. Furthermore, it is more preferable if the heights h of the columnar portions 352 are the same or nearly the same, since this allows the load applied to the columnar portion 352 to be accurately measured without time lag when the contact portion 31 comes into contact with the sample. Here, "nearly the same" refers to a range of 0.95 h to 1.05 h.

[0046] In addition, the columnar portions 352 are arranged so as to have a predetermined distance (spacing) w from adjacent columnar portions 352, and in this embodiment, they are formed uniformly on the lower plate 351 (so that the distance between adjacent stress-luminescent columns is all w).

[0047] The predetermined distance (spacing) w is not particularly limited, but is preferably in the range of 100 nm to 1.00 mm, since it is possible to emit light with high intensity with an emission distribution corresponding to the load distribution on the columnar portion 352; preferably in the range of 500 nm to 500 μm, since it is possible to emit light with even higher intensity with an emission distribution corresponding to the load distribution on the columnar portion 352; and more preferably in the range of 10 μm to 300 μm, since it is possible to emit light with even higher intensity with an emission distribution corresponding to the load distribution on the columnar portion 352.

[0048] Here, different from fluorescent materials, the stress luminescent material has defect levels with a depth of 1 electron volt (eV) or less derived from lattice defects inside the material (crystal), and is not particularly limited as long as it emits light (including visible light, ultraviolet light, near-infrared light, etc.) due to deformation caused by mechanical external force. Examples of the stress luminescent material include those in which the matrix material is composed of a stuffed tridymite structure, a three-dimensional network structure, a feldspar structure, a crystal structure with lattice defect control, a wurtz structure, a spinel structure, a corundum structure, or a β-alumina structure, a perovskite structure, an oxide, a sulfide, a oxysulfide, a phosphate, a silicate, a carbide, a nitride, or an oxynitride, and as the luminescence center, for example, rare earth ions such as Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and transition metal ions such as Ti, Zr, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Nb, Mo, Ta, W.

[0049] Among these, when using, for example, a strontium- and aluminum-containing composite oxide as the matrix material, xSrO·yAl2O3·zMO or xSrO·yAl2O3·zSiO2 is preferably used as the stress luminescent material (M is not particularly limited as long as it is a divalent metal, but Mg, Ca, Ba are preferred. Also, x, y, z represent integers of 1 or more). 10 O 17 :Eu, (Sr x Ba 1-x )Al2O4:Eu (0 < x < 1), BaAl2SiO8:Eu are more preferred. And in this embodiment, the stress luminescent material having an α-SrAl2O4 structure with Eu as the luminescence center is most preferred.

[0050] Furthermore, in order to enhance the luminescence sensitivity to strain, it is preferable to add a substance that generates lattice defects when manufacturing the stress-stimulated luminescent material, and it is particularly preferable to add Ho. By adding such a substance that generates lattice defects, it is possible to improve the luminescence sensitivity to large strain energy. The average particle size of the stress-stimulated luminescent material (measured by laser diffraction) is preferably 20 μm or less, and more preferably 10 μm or less.

[0051] The concentration (weight ratio) of the stress-stimulated luminescent material contained in the columnar section 352 is not particularly limited, but is preferably in the range of 20 wt% to 100 wt%, as this allows the material to emit light with sufficient luminous intensity (brightness), and is more preferably in the range of 50 wt% to 100 wt%, as this allows the material to emit light with even higher luminous intensity.

[0052] Such a columnar section 352 may be made of only the stress-stimulated luminescent material, or may be made by uniformly mixing and curing, for example, epoxy resin, urethane resin, acrylic resin, or silicone resin, a curing agent and a solvent for controlling the crosslinking and curing reaction of these resins, and the stress-stimulated luminescent material and a dispersant and auxiliary agent for uniformly dispersing the stress-stimulated luminescent material.

[0053] Alternatively, the columnar portion 352 may have a center made of a material other than the stress-stimulated luminescent material (e.g., epoxy resin, urethane resin, silicone resin, polylactic acid-glycolic acid copolymer, thermoplastic elastomer, etc.), with the surface coated with the stress-stimulated luminescent material or a mixture of the stress-stimulated luminescent material and epoxy resin, etc., as described above. The columnar portion 352 having such a structure can be manufactured by coating or spraying the stress-stimulated luminescent material or a mixture of the stress-stimulated luminescent material and epoxy resin, etc., onto the material constituting the center, followed by curing. The center of the columnar portion 352 can also be manufactured by a semiconductor process, 3D printing, cutting, transfer using a mold, dispensing material droplets, lifting them up, drying them, or other methods. The columnar portion 352 described above can be manufactured, for example, by the manufacturing method described in International Publication No. WO 2022 / 080333.

[0054] The sample tested with the compression test apparatus 1 is not particularly limited, but preferably has a large area with one side measuring 1 mm or more (1 mm square or more). Even the physical properties of large-area samples that could not be measured in one go using conventional technology can be measured in one go by using the compression test apparatus 1. In particular, as described in JP 2021-191238 A, the compression test apparatus 1 is suitable for applying a technique for applying an external force to cancer cells measuring several micrometers to several tens of micrometers in size and measuring the chloride ion excretion from the cancer cells to cancer tissues measuring several millimeters in size. Known techniques can be used to measure chloride ions in this case. <Operation of compression test equipment>

[0055] 3 is a schematic diagram showing an example of the operation of the compression testing device according to this embodiment. As shown in this figure, after the sample S is placed on the sample stage 70, the load application unit 20 is moved downward, and the contact unit 31 of the load light emitting unit 30 is brought into contact with the sample S. Thereafter, the load application unit 20 is further moved and a load is applied to the sample S, and a load (upward load) equal to the load applied to the sample S is applied to the contact unit 31.

[0056] Then, the load is applied to the light emission source 35 via the contact portion 31. At this time, the upward movement of the light emission source 35 is restricted by the restricting portion 322, so that the same load as that applied to the sample S is ultimately applied to the columnar portion 352 sandwiched between the upper plate 353 and the lower plate 351. As a result, the columnar portion 352 emits light in response to the load.

[0057] The light emitted from the columnar section 352 passes through the upper plate 353 and enters the optical path section 37. The light that enters the optical path section 37 passes through the transmission section 50 and is detected by the optical emission detection section 60 (the optical emission distribution and optical emission intensity are converted into an electrical signal). Then, the control section 40 measures (processes) the optical emission distribution and optical emission intensity of the light detected by the optical emission detection section 60.

[0058] By configuring the compression testing device as described above, it is now possible to perform compression testing in which a load is applied to a large area of ​​1 mm or more (diameter 1 mm or more) with a sensitivity of several tens of nanonewtons (several tens of nN) in a single measurement, something that was not possible with conventional technology. <Example>

[0059] As shown in Figure 4(a), multiple conical microcones (biodegradable resin) made of polylactic acid / glycolic acid copolymer (PLA / GLA copolymer) were arranged in a grid pattern with a 450 μm pitch (w) on a 5.2 mm diameter disk. An epoxy resin containing a mechanoluminescent material (SrAl2O4:Eu) was applied to the surface and dried to create multiple pillars, as shown in Figure 4(b). The pillars had a height (h) of 470 μm. The light-emitting source was fabricated by sandwiching these pillars between an upper plate made of quartz glass with a diameter of 5 mm and a lower plate made of quartz glass with a diameter of 5 mm. A cylindrical contact with a roughly T-shaped cross section and a 2 mm diameter protrusion was then connected to the bottom of the light-emitting source, and these were then placed inside a frame to create the light-emitting device under stress.

[0060] This was attached to a compression test device, and the vertical displacement and the intensity of the light emitted from the light source were measured when the sample was pressed against a smooth surface. The vertical displacement when a load was applied to the sample was measured using a laser displacement meter (Keyence Corporation, LK-H055), and the intensity of the light was measured using a photomultiplier tube module (Hamamatsu Photonics K.K., H11901P-113-01). The applied load was calculated from the vertical displacement using the slope of the force curve measured in advance by a compression test using an atomic force microscope (AFM). The results are shown in Figure 5.

[0061] This figure shows that there is a linear relationship between the load and the luminescence intensity, and by utilizing this relationship, it is possible to calculate the load (at the level of several tens of nN) applied to the sample from the luminescence intensity.

[0062] Furthermore, Figure 6 shows the intensity of light emitted from the light source when a load of approximately 100 nN was repeatedly applied. This figure shows that the present compression testing device shows almost the same intensity of light for the same repeated operation. In other words, by using the compression testing device of the present invention, it is possible to apply loads of several tens of nN to the sample.

[0063] (Other embodiments) In the first embodiment, the device is configured to have a load applying unit and a load light emitting unit, but the present invention is not limited to this. For example, the load light emitting unit itself may be provided with a function to move up and down, and the compression test device may be configured so that the load light emitting unit also functions as the load applying unit. Even when the compression test device is configured in this way, the same effects as those of the first embodiment can be obtained.

[0064] In addition, in the first embodiment, only the contact portion, the light-emitting source portion, and the optical path portion are provided within the frame of the load light-emitting portion, but the present invention is not limited to this. An additional light source portion that can irradiate ultraviolet or visible light onto the light-emitting source portion (columnar portion) within the frame may be provided adjacent to or near the light-emitting source portion. By irradiating the columnar portion of the light-emitting source portion with ultraviolet or visible light from the additional light source portion, the light emission intensity of the light-emitting source portion can be improved.

[0065] Furthermore, in the first embodiment, the load light-emitting unit and the light-emission detector are connected via a transmission unit, but the present invention is not limited to this. For example, instead of the optical path unit of the first embodiment, the light-emission detector may be provided within the frame. That is, the load light-emitting unit and the light-emission detector may be directly connected. By configuring the compression test device in this way, it is possible to suppress a decrease in light intensity due to optical loss in the transmission unit, and therefore it is possible to apply a small load more accurately.

[0066] In the first embodiment, the light-emitting source is composed of multiple pillars containing a stress-stimulated luminescent material at least on the surface or in part of the interior thereof, but the present invention is not limited to this. The light-emitting source may be disk-shaped and contain a stress-stimulated luminescent material on at least the upper surface. Although the light-emitting intensity may be lower, the same effect as in the first embodiment can be obtained.

[0067] Furthermore, in the first embodiment, the shape of the upper plate is disk-shaped, but the present invention is not limited to this. For example, a ring-shaped upper plate with a hollow center may be used so that the light emitted from the columnar portion can pass through as is. By making it ring-shaped, the light emitted from the columnar portion can be incident on the optical path portion without being attenuated.

[0068] In addition, in the first embodiment, the compression test device is configured so that the lower plate is directly connected to the contact portion, but the present invention is not limited to this. The compression test device may also be configured so that a metal layer or the like is provided between the lower plate and the contact portion, and the lower plate is indirectly connected to the contact portion. Even when the compression test device is configured in this way, the same effects as in the first embodiment can be obtained. [Explanation of symbols]

[0069] 1. Compression test equipment 2. Foundation 10 Main body 20 Load bearing section 30 Load light emitting part 31 Contact part 32 Frame 35 Light source 37 Optical path section 40 Control Unit 50 Transmission Unit 60 Luminescence detection unit 70 Sample stage 321 Opening 322 Regulatory Department 351 Lower plate 352 Columnar part 353 Upper Plate S sample

Claims

1. a load applying unit that applies a load to the sample; a stress-induced light-emitting portion including a stress-induced light-emitting material that emits light in response to the load; a light emission detection unit that detects the light emission; A compression testing device comprising: The load light emitting unit is a contact portion having a contact surface that comes into contact with the sample; a light-emitting source section provided on the opposite side of the contact surface of the contact section, the light-emitting source section including a stress-luminescent material that emits light in response to a load applied to the contact section; having A compression testing device characterized by:

2. The load light emitting unit is A hollow frame body; a light-emitting source portion that is disposed within the frame body in a state of being connected to the contact portion and that includes the stress-luminescent material; a restricting portion disposed within the frame and restricting the light source portion from moving within the frame when the contact portion comes into contact with the sample; 2. The compression testing device according to claim 1, further comprising:

3. the light-emitting source unit has a plurality of columnar portions, 3. The compression testing device according to claim 2, wherein the columnar portion contains the mechanoluminescent material on at least a surface or a part of an interior thereof.

4. 4. The compression testing device according to claim 3, wherein the area of ​​one end face of the columnar portion is smaller than the area of ​​the other end face.

5. 5. The compression testing device according to claim 3, wherein the plurality of pillars are uniformly arranged at predetermined intervals.

6. 2. The compression testing device according to claim 1, wherein the sample is cancer tissue.

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