Holder for an atomic force microscope cantilever and atomic force microscope

Abstract

The invention relates to a holder unit for an atomic force microscope cantilever (202), comprising a holder (200) having a connection portion (210) and a holding portion (220), the connection portion being configured to be connected to an atomic force microscope, in particular to a head (100) of an atomic force microscope, the holding portion being configured to hold the cantilever (202) in a desired orientation. Furthermore, the invention relates to an atomic force microscope configured to receive the connection portion (220) of the holder (200), a manufacturing method of the holder (200) and a method of automatically connecting the holder (200) to an atomic force microscope.

Description

Technical Field

[0001] This invention relates to a retainer unit for holding an atomic force microscope cantilever (particularly a force spectrum analyzer), and more particularly to a retainer unit for holding a chip with the cantilever attached. Furthermore, this invention relates to an atomic force microscope. Background Technology

[0002] Among other applications, atomic force microscopy (AFM) has been used to determine the mechanical parameters of samples, such as their stiffness. For example, AFM can be used to determine the stiffness of biological tissue samples to distinguish between healthy tissue and cancer (WO 2012 / 076729). Due to their small size (typically in the µm range), cantilevers used for atomic force microscopy are usually attached to larger structures, such as silicon chips, which are mounted to the holder of the atomic force microscope. Cantilevers have a limited lifespan and must be replaced during long series of experiments. However, using systems according to the prior art, installing a new cantilever (e.g., attaching a new cantilever chip to the holder) is cumbersome and time-consuming and must be performed manually by a trained user. Summary of the Invention

[0003] Therefore, the object of the present invention is to provide a retainer unit and an atomic force microscope (hereinafter also referred to as "AFM") that allows for easy replacement of the cantilever, particularly automated.

[0004] A first aspect of the invention relates to a retainer unit for a cantilever of an atomic force microscope, wherein the retainer unit includes a retainer, the retainer including a connecting portion configured to connect to the atomic force microscope, particularly to the head of the atomic force microscope, wherein the retainer further includes a retaining portion configured to retain the cantilever in a desired orientation.

[0005] In the sense of this specification, a cantilever is a flexible, slender body that includes a tip for contacting a sample, and in particular, obtains a measurement of the sample's stiffness by determining a force curve (forces acting on the cantilever relative to the cantilever's position).

[0006] In some embodiments of the invention, the retainer unit further includes a cantilever, wherein the cantilever is held by a retaining portion of the retainer.

[0007] In some embodiments, the holding portion is configured to hold the chip, wherein a cantilever is attached to the chip. Specifically, the holder unit includes a chip, wherein the chip is held by the holding portion. Furthermore, the holder unit may specifically include a cantilever, wherein the cantilever is attached to the chip.

[0008] In some embodiments, the chip is permanently fixed, for example, bonded to a holder. If the chip is bonded to the holder with an adhesive, the retaining portion of the holder may include a notch disposed at the connection area between the chip and the holder, such that the adhesive can be absorbed by the notch. This measure prevents uncontrolled flow of the adhesive, particularly into the beam path area used to detect cantilever deflection as disclosed herein.

[0009] In some embodiments, the cantilever is permanently fixed, for example, by being bonded to the chip.

[0010] Alternatively, the retaining portion may include a recess, such as a blind via or through-hole, in which the chip is held within the recess of the retaining portion, particularly via a snap-fit ​​or insert connection. This allows for repeated attachment and detachment of the same chip from the retaining portion.

[0011] In the context of this specification, the term "chip" refers to a substantially planar flat body. A chip can be formed, for example, from silicon or a similar material. A chip may include one or more cantilevers, for example, four cantilevers arranged on opposite sides of the chip. The cantilevers or cantilevers may be bonded to the chip.

[0012] According to the present invention, in order to replace the cantilever, the chip is not usually removed from the holder, but the holder together with the chip is removed from the atomic force microscope and replaced by a new holder, especially a new holder that has been pre-attached with a new chip and a new cantilever.

[0013] In some embodiments, the connecting portion is configured to at least partially insert into a slot in the atomic force microscope (AFM), particularly into a slot in the head of the AFM. This improves the positioning of the retainer on the AFM.

[0014] In some embodiments, the connection portion includes a connection surface configured to engage with a clamping element of the atomic force microscope (AFM) to clamp the retainer to the AFM. Clamping provides a means of reversibly attaching the retainer to the AFM, particularly automatically.

[0015] In some embodiments, the retainer comprises or is composed of an optically transparent material. In this way, the light beam used to determine the cantilever deflection can pass through the retainer without being absorbed or reflected.

[0016] In the context of this specification, the term "optically transparent" describes a material that is transparent to visible light.

[0017] In some embodiments, the optically transparent material has a refractive index higher than 1.333. For example, the retainer may be formed of an optically transparent plastic material, an optically transparent polymer, or an optically transparent non-glass material.

[0018] In some embodiments, the retainer is made of a single piece of material.

[0019] In some embodiments, the retaining portion extends along a longitudinal axis from a first end adjacent to the connecting portion to a second end configured to retain the cantilever.

[0020] In some embodiments, the area of ​​the retainer perpendicular to the longitudinal axis is larger at the first end than at the second end. This specifically avoids unwanted collisions between the retainer and the sample.

[0021] In some embodiments, the first end of the retaining portion includes an area perpendicular to the longitudinal axis that is smaller than that of the connecting portion.

[0022] In some embodiments, the retaining portion is truncated cone-shaped. In some embodiments, the retaining portion is shaped as a truncated cone of a rectangular pyramid. In particular, the base of the truncated cone forms a connecting portion or is connected to a connecting portion, and the apex of the truncated cone forms the retaining portion or, in particular, the retaining surface of the retaining portion.

[0023] Specifically, the area of ​​the retaining portion perpendicular to the longitudinal axis decreases from the first end to the second end, wherein the area (cross-sectional area) at the first end is less than or equal to 228 mm², and the area (e.g., the area of ​​the retaining surface) at the second end is less than or equal to 63 mm². Furthermore, in a preferred embodiment, the retaining portion includes a length greater than or equal to 15 mm along the longitudinal axis from the first end to the second end.

[0024] In some embodiments, the retaining portion includes a retaining surface configured to retain a cantilever, particularly a chip to which the cantilever is attached.

[0025] In some embodiments, the holding surface includes a first segment, particularly having a planar surface, and a second segment, particularly having a planar surface, separated by an edge, wherein the first segment extends relative to the second segment at an angle of 0° < α < 90°, particularly 5° < α < 85°, more particularly 10° < α < 80°, even more particularly 20° < α < 70°, and most particularly 30° < α < 60°. This angle allows the cantilever to be centered on the holding surface while being able to freely contact the sample without obstruction by the holder.

[0026] In some embodiments, the retainer, particularly the retaining portion, is hollow. In some embodiments, the retainer forms a cavity and an opening for guiding the cavity. In particular, the retaining portion forms a cavity and / or the connecting portion includes an opening. This is particularly advantageous during retainer manufacturing because such a retainer can be injection molded faster compared to a solid retaining portion. Furthermore, the hollow retaining portion reduces the weight of the retainer.

[0027] In some embodiments, the cavity is frustoconical, particularly shaped as a rectangular pyramid. Specifically, the retainer is also frustoconical, even more particularly shaped as a rectangular pyramid. Thus, the internal profile of the cavity is particularly similar to the external profile of the retainer, which allows for sufficient mechanical stability of the retainer while using minimal material.

[0028] In some embodiments, the cavity formed by the retainer is configured to receive a transparent body of the atomic force microscope when the retainer is connected to the microscope. The transparent body is formed of an optically transparent material. In some embodiments, the transparent body is formed of a glass material. In some embodiments, the material of the transparent body has a refractive index greater than that of air. In some embodiments, the material of the transparent body has a refractive index greater than that of the retainer material. In some embodiments, the transparent body has a refractive index of 1.6 to 2.2, more particularly about 1.9.

[0029] Specifically, when a transparent body is provided, the light beam used to determine the deflection of the cantilever, particularly the free end of the cantilever, passes through the transparent body and the transparent retainer to reach the cantilever, and the light beam reflected from the cantilever returns through the transparent retainer and the transparent body to a reflector, which guides the reflected light beam to a photodetector, such as a photodiode, to determine the deflection of the cantilever. The free end of the cantilever can be formed by mechanical fastening the cantilever to the retainer unit, wherein the free end of the cantilever is the end of the cantilever away from its mechanical fastening portion with the retainer unit, particularly with the retaining portion of the retainer unit. The transparent body improves the stability of the transparent body-retainer assembly, allowing the retainer to be made longer in the z-direction (when attached to an atomic force microscope), while saving material on the retainer, which specifically refers to a disposable consumable that is replaced after a series of measurements. Furthermore, when the material of the transparent body has a higher refractive index than air, this allows the optics of the AFM system to be built more compactly, because the measurement beam from the light source toward the cantilever and the reflected beam from the cantilever to the mirror and photodiode pass through the transparent body rather than the gas-filled cavity of the holder.

[0030] In some embodiments, the cavity comprises a shape that matches the shape of the transparent body. In other words, the transparent body forms a positive shape, and the cavity of the holder forms a corresponding negative shape. This minimizes the air volume between the holder and the transparent body, and the holder and the transparent body together form a continuum, which improves the accuracy of the measurement beam and the reflected beam used to detect cantilever deflection.

[0031] In some embodiments, the shape of the cavity (and particularly the transparent body) is rotationally asymmetric with respect to rotation about the longitudinal axis (extending in the z-direction when the retainer is attached to the AFM head). For example, the cavity and the transparent body have a cross-sectional shape perpendicular to the longitudinal axis that is not circular. This results in the retainer being aligned to the desired orientation when placed on the transparent body, for example during the autoloading of a new retainer with a cantilever chip attached to the AFM head.

[0032] In some embodiments, the cavity (and in particular, the transparent body) tapers gradually along the longitudinal axis from the first end of the retainer toward the second end of the retainer. This further improves the alignment and positioning of the retainer when it is placed on the transparent body.

[0033] In some embodiments, the cavity (and in particular, the transparent body) is truncated cone-shaped, especially truncated cone shaped as a rectangular pyramid.

[0034] In some embodiments, the retainer, particularly the connecting portion, includes a groove, wherein the groove is configured to receive an alignment element of the atomic force microscope when the retainer, particularly the connecting portion, is connected to the atomic force microscope, particularly the head (especially when the connecting portion is inserted into the groove), particularly to align the retainer to a desired position, and more particularly to center it on the atomic force microscope, particularly the head.

[0035] In some embodiments, the retainer, particularly the connecting portion, includes a plurality of grooves, each groove being configured to receive an alignment element of the respective atomic force microscope, particularly the head, when the retainer, particularly the connecting portion, is connected to the atomic force microscope, particularly the head (especially when the connecting portion is inserted into the groove), particularly to align the retainer to a desired position, and more particularly to center it on the atomic force microscope, particularly the head.

[0036] In particular, at least one groove includes a cross section (where the cross section can be one of the following: conical, circular (e.g., hemispherical), triangular) such that the retainer unit can be centered on the atomic force microscope, particularly on the head, by receiving an alignment element, wherein the alignment element can be a pin and / or can include a portion of a sphere, particularly a hemisphere.

[0037] In some embodiments, the retainer, particularly the connecting portion, includes a protrusion configured to engage, particularly insert into, a notch in the atomic force microscope, particularly the head, when the retainer, particularly the connecting portion, is connected to the atomic force microscope, particularly the head (especially when the connecting portion is inserted into a slot), particularly to align the retainer to a desired position, and more particularly to center it on the atomic force microscope.

[0038] In some embodiments, the retainer, particularly the connecting portion, includes a plurality of protrusions, each of which is configured to engage, particularly insert into, a respective notch in the atomic force microscope, particularly the head, when the retainer, particularly the connecting portion, is connected to the atomic force microscope, particularly the head (especially when the connecting portion is inserted into a slot), particularly such that the retainer is aligned to a desired position, and more particularly centered on the atomic force microscope.

[0039] As described above, the retainer unit may include a retainer and a cantilever for an atomic force microscope, wherein the cantilever is held by a retaining portion of the retainer.

[0040] In some embodiments, the retainer unit includes a chip to which a cantilever is attached, wherein the chip is held by a retaining portion of the retainer. Specifically, the chip is permanently attached, for example, bonded to the retaining portion. This advantageously allows for quick and easy (and particularly automatic) replacement of the cantilever by replacing the entire retainer with the chip to which the pre-attached cantilever is attached, thereby streamlining workflows in high-throughput applications such as tissue analysis.

[0041] The second aspect of the invention relates to an atomic force microscope, particularly suitable for force spectrum measurements, configured to receive a connection portion of a retainer according to the first aspect of the invention to connect the retainer to the atomic force microscope, particularly to the head of the atomic force microscope.

[0042] In some embodiments, the atomic force microscope includes a slot configured to at least partially receive a connection portion of a retainer to connect the retainer to the atomic force microscope, particularly to the head of the atomic force microscope.

[0043] In some embodiments, the atomic force microscope includes a head, in other words, a portion movable relative to the sample, particularly bringing the cantilever close to the sample. For example, in a sample stiffness measurement, the head of the cantilever, having a retainer and attachments, is moved toward the sample such that the cantilever, particularly the free end of the cantilever, is pressed into the sample, and then the head is moved away from the sample, wherein the deflection of the cantilever is measured to obtain the force acting on the cantilever, from which the sample stiffness can be determined.

[0044] In some embodiments, the atomic force microscope includes an actuator configured to move the head along a longitudinal axis.

[0045] In some embodiments, the atomic force microscope includes a light source for generating light and focusing optics configured to focus the light and guide a first beam along a longitudinal axis to the cantilever.

[0046] In some embodiments, the atomic force microscope includes a mirror configured to receive and reflect a second beam of light reflected by the cantilever, thereby forming a third beam.

[0047] In some embodiments, the atomic force microscope includes a detector configured to detect the position of a third beam reflected by a mirror and configured to generate a deflection signal indicating the deflection of the cantilever along a longitudinal axis based on the detected position of the third beam.

[0048] When the spring constant of the cantilever is known, the force can be determined from the deflection signal and the spring constant. From this, a force curve of the sample (the position of the cantilever and the force) can be generated, and the stiffness of the sample can be determined from the force curve.

[0049] In some embodiments, the atomic force microscope, particularly the head, includes a through-hole arranged in a slot, wherein the through-hole is configured such that a first beam (from a light source) can pass through the through-hole to a holder and / or a second beam (reflected by a cantilever) can pass through the through-hole to a detector (directly or via a mirror).

[0050] In some embodiments, the atomic force microscope, particularly the head, includes at least one clamping element configured to clamp a retainer to the atomic force microscope in a clamped position, wherein (particularly in the clamped position) when the retainer is received in a slot, the clamping element is configured to engage a connecting portion, particularly the connecting surface of the connecting portion of the retainer.

[0051] In some embodiments, the atomic force microscope includes at least one spring configured to bias a clamping element to a clamped position.

[0052] In some embodiments, the atomic force microscope includes at least one pivoting member, particularly a bolt or shaft, wherein the pivoting member is pivotally received in a bearing included by the atomic force microscope, wherein the pivoting member is connected to a clamping element such that the clamping element is configured to move between a clamped position and an open position by pivoting the pivoting member in the bearing. In the open position, a retainer can be inserted into and / or removed from a slot in the atomic force microscope.

[0053] In some embodiments, the atomic force microscope includes a lever, wherein a pivoting member is connected to the lever.

[0054] In some embodiments, the atomic force microscope also includes a rod movable between a first position and a second position, wherein the rod is configured to engage a lever in the second position, thereby pivoting a pivoting member to bias a clamping element from a clamped position to an open position.

[0055] In some embodiments, the atomic force microscope includes multiple levers, each with a pivoting member connected to it.

[0056] In some embodiments, the atomic force microscope includes a linear motor configured to move a lever between a first position and a second position.

[0057] In some embodiments, the rod includes a pin configured to engage a hole in a connecting lever, wherein the connecting lever is connected to the mirror axis, and wherein the atomic force microscope includes a mirror configured to reflect a beam of light reflected by the cantilever onto the detector of the atomic force microscope, wherein the mirror is connected to the mirror axis such that the mirror can be tilted by pivoting the mirror axis. In this way, the mirror can be tilted by the same linear actuator used to actuate the clamping mechanism.

[0058] In some embodiments, the atomic force microscope, particularly the head, includes a transparent body configured to be inserted into a cavity formed by the retainer when the retainer is attached to the atomic force microscope, particularly the head. The transparent body is formed of an optically transparent material. In some embodiments, the transparent body is formed of a glass material. In some embodiments, the material of the transparent body has a refractive index greater than that of air. In some embodiments, the material of the transparent body has a refractive index greater than that of the retainer material. In some embodiments, the transparent body has a refractive index of 1.6 to 2.2, more particularly about 1.9.

[0059] In some embodiments, the transparent body includes a first end connected to the atomic force microscope, particularly the head, and a second end protruding from the atomic force microscope, particularly the head, along a longitudinal axis (particularly in the vertical z-direction).

[0060] The transparent body improves the stability of the transparent body-holder assembly, allowing the holder to be made longer in the z-direction (when attached to an atomic force microscope), while saving material on the holder, which is specifically a disposable consumable that is replaced after a series of measurements. Furthermore, when the transparent body material includes a higher refractive index than air, this allows for a more compact construction of the optics in the AFM system, as the measurement beam from the light source toward the cantilever and the reflected beam from the cantilever to the mirror and photodiode pass through the transparent body rather than the gas-filled cavity of the holder.

[0061] In some embodiments, the transparent body comprises a shape that matches the shape of the cavity of the retainer. In other words, the transparent body forms a positive shape, and the cavity of the retainer forms a corresponding negative shape. This minimizes the air volume between the retainer and the transparent body, and the retainer and the transparent body together form a continuum, which improves the accuracy of the measurement beam and the reflected beam used to detect cantilever deflection.

[0062] In some embodiments, the shape of the transparent body (and particularly the cavity of the retainer) is rotationally asymmetric with respect to rotation about the longitudinal axis (extending in the z-direction when the retainer is attached to the AFM head). For example, the transparent body (and particularly the cavity) has a cross-sectional shape perpendicular to the longitudinal axis that is not circular. This results in the retainer being aligned to the desired orientation when placed on the transparent body, for example during the autoloading of a new retainer with an attached cantilever chip onto the AFM head.

[0063] In some embodiments, the transparent body tapers gradually along its longitudinal axis from a first end toward a second end. This further improves the alignment and positioning of the retainer when it is placed on the transparent body.

[0064] In some embodiments, the transparent body is arranged in a slot in the head of the atomic force microscope.

[0065] In some embodiments, the cavity (and in particular, the transparent body) is truncated cone-shaped, especially truncated cone shaped as a rectangular pyramid.

[0066] In some embodiments, the atomic force microscope, particularly the head, includes an alignment element configured to engage a groove in the holder, particularly the connecting portion, when the holder, particularly the connecting portion, is connected to the atomic force microscope, particularly the head (especially when the connecting portion is inserted into a slot in the atomic force microscope), thereby aligning the holder to a desired position, and more particularly to center it on the atomic force microscope, particularly the head.

[0067] In some embodiments, the atomic force microscope, particularly the head, includes a plurality of alignment elements, each of which is configured to engage a respective groove of the retainer, particularly the connecting portion, when the retainer, particularly the connecting portion, is connected to the atomic force microscope (especially when the connecting portion is inserted into a slot), such that the retainer is centered on the atomic force microscope.

[0068] In some embodiments, the alignment element is a hemisphere.

[0069] In some embodiments, alignment elements are arranged in slots.

[0070] In some embodiments, the atomic force microscope, particularly the head, includes a notch configured to receive a protrusion of the retainer, particularly the connecting portion, when the retainer, particularly the connecting portion, is connected to the atomic force microscope, particularly the head (especially when the connecting portion is inserted into a slot), particularly to align the retainer to a desired position, and more particularly to center it on the atomic force microscope.

[0071] In some embodiments, the atomic force microscope, particularly the head, includes a plurality of notches, each notch being configured to receive a respective protrusion of the retainer's connection portion when the retainer's connection portion is attached to the atomic force microscope (particularly when the connection portion is inserted into a slot in the atomic force microscope), thereby centering the retainer on the atomic force microscope.

[0072] In some embodiments, a notch or multiple notches are arranged in a groove.

[0073] In some embodiments, the atomic force microscope includes a retainer unit according to a first aspect of the invention.

[0074] A third aspect of the invention relates to a method of manufacturing a retainer according to a first aspect of the invention, wherein the retainer is formed by injection molding. Specifically, the retaining portion is hollow, and more particularly, the connecting portion includes an opening leading to a cavity formed by the (hollow) retaining portion.

[0075] The fourth aspect of the invention relates to a method for automatically connecting a holder according to the first aspect of the invention to an atomic force microscope according to the second aspect of the invention, wherein the holder is positioned in a receiving position, and wherein the atomic force microscope, particularly the head, is automatically moved, particularly lowered, toward the receiving position, and wherein the holder is automatically connected to the atomic force microscope, particularly to the head of the atomic force microscope.

[0076] In some embodiments, at least one clamping element is brought to the open position in the receiving position or before reaching the receiving position.

[0077] In some embodiments, the retainer is automatically connected to the atomic force microscope by automatically moving at least one clamping element to a clamping position.

[0078] Whenever alternatives to a single separable feature, such as a homologous protein or coding sequence, or cancer, are listed herein as “examples,” it should be understood that such alternatives may be freely combined to form discrete embodiments of the invention disclosed herein. Attached Figure Description

[0079] In the following description, embodiments and further features and advantages of the invention are described with reference to the accompanying drawings, wherein: Figure 1A B illustrates a retainer unit according to an embodiment of the present invention; Figure 2 A front view of a portion of the head of an atomic force microscope connected to a retainer according to the invention is shown; Figure 3 It shows Figure 2 A side view of a portion of the head and retainer shown; Figure 4 A bottom view of the head of an atomic force microscope with a slot for inserting a retainer is shown. Figure 5 A bottom view of the head of an atomic force microscope in a retainer insertion slot is shown; Figure 6 A cross-sectional view of the head of an atomic force microscope is shown. Figure 7 A transparent body is shown as part of an atomic force microscope according to an embodiment of the present invention; Figure 8 An anchoring plate is shown for anchoring a transparent body to the head of an atomic force microscope according to an embodiment of the present invention; Figure 9 A side view of the head of an atomic force microscope with its retainer attached is shown; and Figures 10A and 10B show the optical path of light emitted from the light source and reflected from the cantilever and mirror to the detector (Figure 10A), where the transparent body is arranged in... Figure 10B In the retainer unit shown.

[0080] List of reference numerals in the attached diagram: Sample 3 Head 100 First linear driver 101 First coarse linear motor 101a First fine linear motor 101b Second linear driver 102 Second coarse linear motor 102a Second fine linear motor 102b Third linear drive 103 Third coarse linear motor 103a Third fine linear motor 103b Light source 105 Slot 106 Through hole 107 Alignment element 108 Mirror 112 Detector 113 Mirror axis 114a Mirror driver 114b 119 Sales 120 Connecting lever 121 Kong 121a Clamping element 122 Pivoting component 123 Bearing 124 Leverage 125 Pile body 125a Transparent body 130 First end 131 Second end 132 133 convex plate Base section 134 Highlight 135 Anchor plate 140 Incision 141 Hole 142 Temperature sensor 150 Retainer 200 Chip 201 Cantilever 202 Advanced 203 Connection part 210 Connection surface 211 Opening 212 Groove 213 Keep part 220 First end 221 Second end 222 Maintain surface 223 Section 1, 224 Section 225 Edge 226 Cavity 227 Sample stage 300 First beam B1 Second beam B2 Third beam B3 Longitudinal axis L First longitudinal axis L1 Second longitudinal axis L2 Third longitudinal axis L3 Detailed Implementation

[0081] Figure 1A and Figure 1B These are different views of an embodiment of a retainer unit including a retainer 200 according to the present invention, showing the retainer 200 from different perspectives.

[0082] The retainer 200 includes a connecting portion 210 and a retaining portion 220. The retaining portion 220 includes a retaining surface 223, to which a chip 201 (e.g., a silicon chip) including at least one cantilever 202 is preferably permanently attached, for example, by adhesive bonding. The connecting portion 210 is configured to insert into a slot 106 of the head 100 of an atomic force microscope (see [link to documentation]). Figure 4 and Figure 5To clamp the retainer 200 to the head 100.

[0083] The connecting portion 210 is annular and includes a cylindrical geometry with a circular cross-section perpendicular to the longitudinal axis L, which forms the central cylindrical axis. Specifically, when the retainer 200 is attached to the head 100 of the atomic force microscope, the entire retaining portion 210 is inserted into the slot 106 of the head 100 (see [link to documentation]). Figure 5 ).

[0084] The connecting portion 210 also forms two connecting surfaces 211, which are configured to engage with the clamping element 122 of the head 100 of the atomic force microscope to clamp the retainer 200 to the head 100 (see [link]). Figure 5 ).

[0085] like Figure 1B As best shown, the connecting portion 210 includes three grooves 213 on its bottom surface, which are equally spaced around the periphery of the connecting portion 210, i.e., arranged at an angle of 120° around the periphery. The grooves 213 have a circular shape (or other shapes as described herein) and are configured to receive corresponding alignment elements 108 of the head 100, such as ceramic hemispheres, which are arranged in slots 106 of the head 100 (see [link to documentation]). Figure 4 This allows for alignment, particularly centering of the retainer 200 within the slot 106. Furthermore, within the scope of this disclosure, it is envisioned that the connecting portion 210 of the retainer 200 includes a plurality of protrusions instead of recesses 213, which insert into corresponding notches (not shown) in the slot 106 adjacent to the AFM head 100 for alignment, particularly centering of the retainer 200 on the AFM head 100.

[0086] The retaining portion 220 of the retainer 200 extends from the first end 221 to the second end 222. The retaining portion 220 tapers gradually from the first end 221 toward the second end 222, which facilitates the insertion of the retainer 200, in particular, into the slot 106 of the AFM head 100.

[0087] As from Figure 1AAs can be best observed, the holding surface 223 at the second end 222 of the holding portion 220 includes a first segment 224 and a second segment 225 separated by an edge 226. Thus, the first segment 224 and the second segment 225 are arranged at an angle relative to each other, wherein the angle is greater than 0° and less than 90°. The chip 201, including the cantilever 202, is attached to the first segment 224 of the holding surface 223. Due to the angle between the first segment 224 and the second segment 225, the cantilever 202, including the tip 203 attached to the end of the chip 201 oriented towards the edge 226, is not obstructed by the holding portion 220 and can freely contact the sample. In particular, the chip 201 can be bonded to the holding surface 223 (especially to the first segment 224) by an adhesive. Alternatively, the chip 201 can also be mechanically connected to the holding portion 220 by engaging a recess that can be formed, for example, in the first segment 224. For this purpose, the first segment 224 may protrude beyond the second segment 225.

[0088] like Figure 1B As best shown, the retaining portion 220 of the retainer 200 is hollow and forms a cavity 227, which can be accessed through the opening 212 of the connecting portion 210. This simplifies the manufacturing of the retainer 200, for example, by injection molding. Furthermore, the cavity 227 is adapted to accommodate, for example, Figure 7 The transparent body 130 of the AFM head 100 according to the embodiment described herein.

[0089] Figure 2 A front view is shown. Figure 3 A side view of the retainer 200 arranged in the slot 106 of the head 100 is shown.

[0090] Figure 4 A bottom view of the head 100 of an atomic force microscope according to an embodiment of the present invention is shown, including a circular groove 106 for inserting a connecting portion 210 of a retainer 200 and a circular through-hole 107 centrally arranged in the groove 106. Three alignment elements 108 formed of ceramic hemispheres are arranged in the groove 106 around the periphery of the through-hole 107 to align, and in particular to center, the retainer 200 when it is inserted into the groove 106. The edges around the groove 106 may additionally be tapered to allow easy insertion of the retainer 200.

[0091] The through-hole 107 is configured to allow a beam of light from a light source of an atomic force microscope to pass through an optically transparent holder 200 to a cantilever 202 on a chip 201 held by the holder 200, and to allow a reflected beam from the cantilever 202 to pass through a mirror disposed in the head 100, which reflects the beam to a detector (e.g., a photodiode), so that the deflection of the cantilever 202 can be determined by the detector.

[0092] Figure 5 A retainer 200 according to the invention is shown inserted into a slot 106 of the head 100 of an atomic force microscope. The retainer 200 is held in a clamped position by two clamping elements 122 arranged on opposite sides of the slot 106, which engage a connecting surface 211 of the retainer 200 to secure the retainer 200 in the slot 106. Furthermore, the clamping elements 122 are connected to pivoting members 123 (e.g., rods) that are pivotally mounted in bearings 124. One end of each pivoting member 123 is also connected to a lever 125. Each lever 125 includes a stake 125a configured to attach a spring, such as a leaf spring, to bias the clamping element 122 to… Figure 5 The clamping position is shown. Lever 125 from... Figure 5 The outer part of the head 100 shown extends to Figure 6 The interior of the head 100 shown allows the lever 125 to be operated by a rod 119 arranged inside the head 100.

[0093] exist Figure 6 The middle lever 125 is shown from inside the head 100. (See image) Figure 6 As shown, the head 100 also includes a rod 119 configured to move along a longitudinal axis L, for example by a linear motor. Figure 6 In the middle, when lever 119 moves downward from the position shown, lever 119 engages lever 125 and pushes lever 125 against the force of the spring to the downward position (in Figure 6 In the middle, the left lever 125 is shown in the downward position. Conversely, the pivot member 123 is pivoted, thereby forcing the clamping element 122 into the open position (not shown), whereby the retainer 200 can be inserted into or removed from the slot 106, particularly automatically.

[0094] According to a further embodiment of the atomic force microscope, the head 100 may include a mirror pivotally coupled to the mirror axis 114a (see [reference]). Figure 6 The connecting lever 121 is connected to the mirror axis 114a. The connecting lever 121 also includes a hole 121a, such as an oblong hole, into which a pin 120, either connected to or integrally formed with the lever 119, is inserted. As the lever 119 moves linearly along the longitudinal axis L, the pin 120 moves within the hole 121a, thereby pivoting the connecting lever 121 about the mirror axis 114a, resulting in the pivoting movement of the mirror about the mirror axis 114a. In this way, the pivoting of the mirror and the opening of the clamping element 122 to insert or remove the retainer 200 can be achieved by a single linear motor of the head 100, which reduces the size, weight, and complexity of the head 100.

[0095] Figure 7A view of a transparent body 130 made of an optically transparent material is shown, which is configured to be inserted into a cavity 227 formed by the retainer 200 when the retainer 200 is attached to the AFM head 100, for example by clamping as described above.

[0096] A transparent body 130 extends from a first end 131 to a second end 132 along a longitudinal axis L (which, when used with an AFM, extends particularly in the vertical direction when the transparent body 130 is mounted on the AFM head 100). A cuboid-shaped base portion 134 of the transparent body 130 is formed at the first end 131, wherein the base portion 134 includes two tabs 133 formed at opposite lateral ends of the base portion 134. A truncated pyramidal projection 135 extends from the base portion 134 along the longitudinal axis L toward the second end 132. The projection 135 is adapted to be inserted into a cavity 227 formed by the retainer 200 when the retainer 200 is attached to the AFM head (see...). Figure 9 This improves the structural integrity of the retainer 200 head 100 assembly, and the optically transparent body 130 is transparent to light traveling between the cantilever 202 and the measurement optics inside the AFM head, which are used to measure the deflection of the cantilever 202, particularly during force spectrum measurements.

[0097] Figure 8 A perspective view of an anchoring plate 140 is shown, which is configured to... Figure 7 The transparent body 130 shown is mounted to the head 100. The anchor plate 140 has a disc shape with a central rectangular cutout 141 and three equidistant circular holes 142 around the periphery of the anchor plate 140. The holes 142 are configured to receive screws or bolts to secure the anchor plate 140 to the AFM head 100. The cutout 141 is configured such that a protrusion 135 of the transparent body 130 passes through the cutout 141. A tab 133 of the transparent body 130 is clamped, in particular, between the anchor plate 140 and another component (e.g., a ring) of the head 100 for receiving a retainer 200 (see [link to image]) at the bottom end of the AFM head 100. Figure 9 ).

[0098] like Figure 9 As shown, the retainer 200 can be inserted into the slot 106 of the head 100, while the transparent body 140 is inserted into the cavity 227 of the retainer 200. The retainer 200 can then be clamped in the slot 106 unit by clamping elements 122, which engage the connecting surface 211 as described above. Optionally, similar to... Figure 4 and Figure 5In the embodiment shown, the retainer 200 can be aligned by protrusions 108 arranged in the groove 106, which are inserted into the recess 213 of the connecting portion 210 of the retainer 200, or alternatively by protrusions on the connecting portion 210 of the retainer 200 being inserted into recesses (not shown) in the groove 106.

[0099] In particular, the cavity 227 of the retainer 200 has the same shape as the protrusion 135 of the transparent body, so that there is almost no air space between the retainer 200 and the transparent body 130, which improves the optical properties of the system. The fit between the cavity 227 and the protrusion 135 can also advantageously align the retainer 200, especially during automatic replacement of the retainer 200, to achieve proper positioning of the retainer 200 and the cantilever 202 attached thereto.

[0100] Figure 9 A temperature sensor 150 (e.g., an infrared sensor) is also shown attached to the bottom of the head 100 of the AFM. This sensor 150 is positioned close to the sample during force spectrum measurements and can be advantageously used to obtain the sample temperature in real time during the measurement.

[0101] Figure 10A schematically depicts the optical path of light emitted from light source 105 and detected by detector 113. Light is emitted from light source 105 as a first beam B1 to cantilever 202 held by holder 200. From cantilever 202, particularly from the top surface of cantilever 202 facing light source 105, light is reflected as a second beam B2 to mirror 112, which can be rotated by mirror driver 114b. From mirror 112, light is finally reflected as a third beam B3 to detector 113, which may be a four-quadrant photodiode. The optical path can be altered by moving light source 105 relative to cantilever 202 using a cross stage with first, second, and third light source linear drivers along the x, y, and z directions, respectively. Furthermore, photodetector 113 can be moved along the x-direction (i.e., outside the drawing plane shown in Figure 10A) by detector linear driver. The deflection of cantilever 202 indicates the distance between the tip 203 of cantilever 202 and sample 3 arranged on sample stage 300.

[0102] Figure 10A also schematically illustrates a first linear actuator 101 having a coarse linear motor 101a and a fine linear motor 101b for moving the cantilever 202 held by the retainer 200 along a first longitudinal axis L1, and a second linear actuator 102 having a coarse linear motor 102a and a fine linear motor 102b for moving the cantilever 202 held by the retainer 200 along a second longitudinal axis L2. Furthermore, the sample stage 300 can be moved along a third longitudinal axis L3 by a third linear actuator 103 including a coarse linear motor 103a and a fine linear motor 103b.

[0103] Figure 10B An embodiment is shown in which a retainer 200 is configured to receive a transparent body 130. The transparent body 130 is formed of an optically transparent material, such as glass. Specifically, the material of the transparent body has a refractive index greater than that of air. In some embodiments, the material of the transparent body has a refractive index greater than that of the material of the retainer. For example, the transparent body has a refractive index of 1.6 to 2.2, more particularly about 1.9.

[0104] With the transparent body 130 provided, the light beam used to determine the deflection of the free end of the cantilever 202 passes through the transparent body 130 and reaches the cantilever 202, and the light beam reflected from the cantilever 202 travels through the transparent body 130 toward the mirror 112. At the interface of the transparent body 130, the light is refracted. The transparent body 130 improves the stability of the assembly formed by the transparent body 130 and the holder 200, allowing the holder 200 to be made longer in the z-direction, which simplifies the handling of the holder 200. Furthermore, when the material of the transparent body includes a higher refractive index than air, this allows the optics of the atomic force microscope 1 to be constructed more compactly, because the refraction of the light beam at the transparent body 130 allows the light beam to be refracted to the mirror 112, whereas without the transparent body 130, the light must be completely reflected from the cantilever 202 and guided from the cantilever 202 to the mirror, which would require the holder 200 to have a rather bulky shape, as can be understood by comparing the holders 200 of Figures 10A and 10B.

Claims

1. A retainer unit for a cantilever (202) of an atomic force microscope, the retainer unit comprising a retainer (200) comprising: The connecting part (210) is configured to connect to the atomic force microscope, and in particular to the head (100) of the atomic force microscope; And a retaining portion (220) is configured to retain the cantilever (202) in a desired orientation, wherein, in particular, the retainer unit includes the cantilever (202) held by the retaining portion (220).

2. The retainer unit according to claim 1, wherein, The holding portion (220) is configured to hold the chip (201), to which the cantilever (202) is attached or attachable, wherein, in particular, the holder unit includes the chip (201), wherein the chip (201) is held by the holding portion (220).

3. The retainer unit according to claim 1 or 2, wherein, The connecting portion (210) is configured to be at least partially inserted into the slot (106) of the atomic force microscope, particularly into the slot (106) of the head (100) of the atomic force microscope, wherein, in particular, the connecting portion (210) includes a connecting surface (211) configured to be engaged by the clamping element (122) of the atomic force microscope to clamp the retainer (200) to the atomic force microscope.

4. The retainer unit according to any one of the preceding claims, wherein, The retainer (200) comprises or is composed of an optically transparent material.

5. The retainer unit according to any one of the preceding claims, wherein, The retaining portion (220) extends along a longitudinal axis (L) from a first end (221) to a second end (222), the first end being adjacent to the connecting portion (210), and the second end being configured to retain the cantilever (202), wherein the area of ​​the retaining portion (220) perpendicular to the longitudinal axis (L) is greater at the first end (221) than at the second end (222), wherein, in particular, the first end (221) of the retaining portion (220) includes a smaller area perpendicular to the longitudinal axis (L) than that of the connecting portion (210).

6. The retainer unit according to claim 5, wherein, The area of ​​the retaining portion perpendicular to the longitudinal axis decreases from the first end to the second end, wherein the area at the first end is less than or equal to 228 mm², and the area at the second end is less than or equal to 63 mm².

7. The retainer unit according to any one of the preceding claims, wherein, The retaining portion (220) includes a retaining surface (223) configured to retain the cantilever (202), particularly the chip (201) to which the cantilever (202) is attached. Specifically, the retaining surface (223) includes a first segment (224) and a second segment (225) separated by an edge (226). Specifically, the first segment (224) extends relative to the second segment (225) at an angle α, wherein 0° < α < 90°, and particularly 5° < α < 85°.

8. The retainer unit according to any one of the preceding claims, wherein, The retaining portion (220) is hollow, wherein, in particular, the connecting portion (210) includes an opening (212) leading to a cavity (227) formed by the retaining portion (220), wherein, in particular, the cavity (227) formed by the retainer (200) is configured to receive the transparent body (130) of the atomic force microscope when the retainer (200) is connected to the atomic force microscope, wherein, in particular, the cavity (227) includes a shape that matches the shape of the transparent body (130).

9. The retainer unit according to any one of the preceding claims, wherein: a. The connecting portion (210) includes at least one groove (213), particularly a plurality of grooves (213), wherein the at least one groove (213) is configured to receive an alignment element (108) of the atomic force microscope, particularly the head (100), when the connecting portion (210) is connected to the atomic force microscope, particularly to the head (100), particularly such that the retainer (200) is centered on the atomic force microscope, particularly the head (100); and / or b. The connecting portion (210) includes at least one protrusion, and in particular a plurality of protrusions, wherein the protrusions are configured to engage, and in particular insert into, a notch in the atomic force microscope, and in particular the head (100), when the connecting portion (210) is connected to the atomic force microscope, and in particular to the head (100), such that the retainer (200) is centered on the atomic force microscope, and in particular the head (100).

10. The retainer unit according to any one of claims 4 to 9, wherein, The optically transparent material includes or is composed of one of the following materials: plastic materials, polymers, and non-glass materials.

11. The retainer unit according to claim 9 or 10, wherein, The at least one groove (213) includes a cross section such that the retainer unit can be centered on the atomic force microscope, particularly the head (100), by receiving the alignment element (108) in the at least one groove (213), wherein, in particular, the cross section is one of a cone, a circle, or a triangle, and wherein, in particular, the alignment element (108) includes a portion of a sphere, particularly a hemisphere.

12. The retainer unit according to any one of claims 2 to 11, wherein, The chip (201) is held by the retaining portion (220) by an adhesive.

13. The retainer unit according to any one of claims 2 to 11, wherein, The retaining portion (220) includes a recess, particularly in the form of a blind hole or a through hole, wherein the chip (201) is held in the recess of the retaining portion (220), particularly by a snap-fit ​​connection or an insertion connection.

14. An atomic force microscope comprising a retainer unit according to any one of claims 1 to 13, wherein, in particular, the atomic force microscope comprises a slot (106) configured to receive the connection portion (210).

15. The atomic force microscope according to claim 14, wherein, The atomic force microscope includes at least one clamping element (122) configured to clamp the retainer (200) to the atomic force microscope in a clamped position, wherein, in the clamped position, when the retainer (200) is received in the groove (106), the clamping element (122) is configured to engage the connecting portion (210), particularly the connecting surface (211) of the connecting portion (210) of the retainer (200), wherein, in particular, the atomic force microscope includes at least one spring configured to bias the clamping element (122) to the clamped position.

16. The atomic force microscope according to claim 14 or 15, wherein, The atomic force microscope includes at least one pivot member (123), particularly a bolt or shaft, wherein the pivot member (123) is pivotally received in a bearing (124) included by the atomic force microscope, wherein the pivot member (123) is connected to the clamping element (122) such that the clamping element (122) is configured to move between a clamped position and an open position by pivoting the pivot member (123) in the bearing (124), in which the retainer (200) can be inserted into and / or removed from the slot (106) of the atomic force microscope.

17. The atomic force microscope according to claim 16, wherein, The atomic force microscope includes at least one lever (125), wherein the pivoting member (123) is connected to the lever (125), wherein, in particular, the atomic force microscope also includes a rod (119) movable between a first position and a second position, wherein the rod (119) is configured to engage the lever (125) in the second position, thereby pivoting the pivoting member (123) to bias the clamping element (122) from the clamped position to the open position, wherein, in particular, the atomic force microscope includes a linear motor configured to, in the first The rod (119) is moved between the first position and the second position, wherein, in particular, the rod (119) includes a pin (120) configured to engage a hole (121a) in a connecting lever (121), wherein the connecting lever (121) is connected to a mirror axis (114a), wherein the atomic force microscope includes a mirror configured to reflect a light beam reflected by the cantilever (202) onto a detector of the atomic force microscope, wherein the mirror is connected to the mirror axis (114a) such that the mirror can be tilted by pivoting the mirror axis (114a).

18. The atomic force microscope according to any one of claims 14 to 17, wherein: a. The atomic force microscope includes at least one alignment element (108), particularly a hemisphere, specifically arranged in the slot (106), configured to engage the groove (213) of the connecting portion (210) of the retainer (200) when the connecting portion (210) is connected to the atomic force microscope, particularly such that the retainer (200) is centered on the atomic force microscope: and / or b. The atomic force microscope includes at least one groove, particularly arranged in the groove (106), configured to receive a protrusion of the connecting portion (210) of the retainer (200) when the connecting portion (210) is connected to the atomic force microscope, particularly such that the retainer (200) is centered on the atomic force microscope.

19. The atomic force microscope according to any one of claims 14 to 18, wherein, The atomic force microscope, particularly the head (100), includes a transparent body (130) formed of an optically transparent material, wherein the transparent body (130) is configured to be inserted into a cavity (227) formed by the retainer (200) when the retainer (200) is connected to the atomic force microscope, particularly to the head (100), wherein, in particular, the transparent body (130) includes a shape that matches the shape of the cavity (227).

20. A method for automatically connecting a retainer (200) according to any one of claims 1 to 13 to an atomic force microscope according to any one of claims 14 to 19, wherein, The retainer (200) is positioned in a receiving position, and wherein the atomic force microscope, particularly the head (100), automatically moves toward the receiving position, particularly in the open position of the at least one clamping element (122), and wherein the retainer (200) is automatically connected to the atomic force microscope, particularly by automatically moving the at least one clamping element (122) to the clamping position.

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