Nanometer positioner and piezoelectric actuator

Abstract

A nanopositioner 10 includes a base 12 including a base plate 18 carrying a set of base bearings 22, a carrier 14 movably carried relative to the base 12 and including a carrier plate 56 carrying a set of carrier bearings 58 operatively coupled to the set of base bearings 22. The nanolocator 10 may include a variable area capacitive position sensor, and / or an actuator 16 operatively coupling the carrier 14 to the base 12, the actuator including an armature 100 fixed relative to the carrier 14 and a stator 98 removably coupled to the base 12 to facilitate removal and replacement of at least a portion of the stator 98. A method of producing the nanolocator, and a piezoelectric actuator 16 that may be used with the nanolocator, are also disclosed.

Description

Technical Field

[0001] The present disclosure relates generally to positioning devices and, more particularly, to nanopositioners. Background Art

[0002] Nanopositioners are used in many applications, including, for example, scanning probe microscopy and cryogenic research equipment. In a room temperature environment, a nanopositioner moves the observed sample over a typical range of motion of several millimeters, with step sizes as low as 1 nanometer, although there are significant step variations of about 30-50%. Nanopositioners, also known as motors, typically include a slip-stick (or stick-slip) piezoelectric actuator that provides the motive force according to a slip-stick cycle. The cycle has a slow ramp in which the piezoelectric drive element of the motor adheres to or maintains contact with the driven element of the motor, and also has a fast ramp in which the piezoelectric drive element slips from the driven element or breaks contact with the driven element. Reversal of direction of the driven element is achieved via an antisymmetric power waveform applied to the piezoelectric drive element. Nanopositioners and piezoelectric actuators have been known and used for decades with great success, especially in room temperature environments.

[0003] However, successful implementation of nanopositioners and piezoelectric actuators has been challenged in cryogenic environments. Currently available nanopositioners operate at relatively low voltages of about 30 to 70 volts and relatively high currents of about 10 milliamps, with a position repeatability of about 2 microns. However, these nanopositioners use relatively large piezoelectric stacks that operate at relatively high capacitances on the order of 5 to 10 microfarads, thereby generating undesirable amounts of heat in cryogenic environments. And many piezoelectric actuators are prone to premature wear, which may be attributed to arcing. However, the inventors have discovered a simple and elegant solution in the form of a currently disclosed nanopositioner that can generate significantly less heat than conventional nanopositioners and can also increase position repeatability, and / or in the form of a currently disclosed piezoelectric actuator that can resist premature wear or wear that occurs during the normal life of the piezoelectric actuator, as described below. Summary of the invention

[0004] An illustrative embodiment of a nanopositioner includes a pedestal including a pedestal plate having a pedestal bottom and a pedestal top, and an actuator eyelet, the pedestal bottom having a bottom surface, the pedestal top having a position driver mounting surface and a pedestal bearing mounting surface outboard of the position driver mounting surface, the actuator eyelet extending between the bottom surface and the position driver mounting surface. The nanopositioner also includes a position driver and a set of pedestal bearings, the position driver being carried by the position driver mounting surface of the top of the pedestal plate and including a set of drive electrodes, the set of pedestal bearings being carried by the pedestal bearing mounting surface of the top of the pedestal plate. The nanopositioner also includes a carrier movably carried relative to the pedestal and including a carrier plate having a top and a bottom, the top having a top surface, the bottom having a position receiver mounting surface and a carrier bearing mounting surface outboard of the position receiver mounting surface, the position receiver mounting surface corresponding to and facing the position driver mounting surface of the top of the pedestal plate of the pedestal. The nanopositioner also includes a position receiver and a set of carrier bearings, the position receiver being carried by a position receiver mounting surface of a bottom portion of the carrier plate and including a sense electrode operatively coupled to the set of drive electrodes, the set of carrier bearings being carried by a carrier bearing mounting surface of a bottom portion of the carrier plate and operatively coupled to the set of base bearings. In addition, the nanopositioner includes an actuator operatively coupling the carrier to the base and including a stator and an armature, the stator being removably coupled to the base to facilitate removal and replacement of at least a portion of the stator, the armature being operatively coupled to the stator, extending through an actuator eyelet of a base plate of the base, and coupled to the carrier. The sense electrode and the set of drive electrodes at least partially form a variable area capacitive position sensor.

[0005] Another illustrative embodiment of a nanopositioner includes a base including a base plate including an actuator eyelet therethrough, a position driver carried by the base plate and including a set of drive electrodes, and a set of base bearings carried by the base plate. The nanopositioner also includes a carrier movably carried relative to the base and including a carrier plate, a position receiver carried by the carrier plate and including a sense electrode operatively coupled to the set of drive electrodes, and a set of carrier bearings carried by the carrier plate and operatively coupled to the set of base bearings. The nanopositioner also includes an actuator operatively coupling the carrier to the base and including an armature and a stator, the armature being fixed relative to the carrier and the stator being removably coupled to the base to facilitate removal and replacement of at least a portion of the stator.

[0006] Yet another illustrative embodiment of a nanopositioner includes a base including a base plate, a position driver, and a set of base bearings, the base plate including an actuator eyelet passing through the base plate, the position driver carried by the base plate and including a set of drive electrodes, the set of base bearings carried by the base plate. The nanopositioner also includes a carrier movably carried relative to the base and including a carrier plate, a position receiver, and a set of carrier bearings, the position receiver carried by the carrier plate and including sense electrodes operatively coupled to the set of drive electrodes, the set of carrier bearings carried by the carrier plate and operatively coupled to the set of base bearings. The nanopositioner also includes an actuator operatively coupling the carrier to the base and including a stator and an armature, the stator being fixed relative to the base, the armature being operatively coupled to the stator, extending through the actuator eyelet of the base plate of the base, and coupled to the carrier.

[0007] Additional illustrative embodiments of a nanopositioner include a base including a base plate including an actuator eyelet therethrough, a position driver carried by the base plate and including a set of drive electrodes, the set of pedestal bearings carried by the base plate. The nanopositioner also includes a carrier movably carried relative to the base and including a carrier plate, a position receiver and a set of carrier bearings, the position receiver carried by the carrier plate and including a sense electrode operatively coupled to the set of drive electrodes, the set of carrier bearings carried by the carrier plate and operatively coupled to the set of pedestal bearings. The sense electrode and the set of drive electrodes at least partially form a variable area capacitive position sensor.

[0008] An illustrative embodiment of a method for producing a nanopositioner includes: processing the top surface and bottom surface of a base plate to be parallel to each other within a tolerance of the base plate; processing the top surface and bottom surface of a carrier plate to be parallel to each other within a tolerance of the carrier plate; mounting an actuator armature to the bottom surface of the carrier plate; processing the bottom surface of a platform of the armature to be parallel to the top surface of the carrier plate within the tolerance of the armature; removing the actuator armature from the carrier plate; mounting a position receiver to the bottom surface of the carrier plate; mounting a position drive plate support to the top surface of the base plate; mounting the position drive plate to a support on the top surface of the base plate; measuring the parallelism of the position drive plate to obtain a parallelism measurement value of the drive plate; and using the parallelism measurement value to process the top surface of the drive plate support so that the top surface of the drive plate is parallel to the bottom surface of the base plate within the drive plate tolerance.

[0009] An illustrative embodiment of a piezoelectric stack includes a main piezoelectric element having main opposing faces and main sides extending between the main opposing faces; an auxiliary piezoelectric element having auxiliary opposing faces and auxiliary sides extending between the auxiliary opposing faces; and a conductive foil disposed between facing ones of the main opposing faces and the auxiliary opposing faces of the main piezoelectric element and the auxiliary piezoelectric element and having at least one tab extending laterally outward relative to at least one main side and at least one auxiliary side. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a top rear perspective view according to an illustrative embodiment of a nanopositioner.

[0011] Figure 2 yes Figure 1 An exploded elevation view of a nanopositioner comprising an embodiment of a base, an embodiment of a carrier configured to be movably carried by the base, and an embodiment of an actuator configured to movably couple the carrier relative to the base.

[0012] Figure 3 yes Figure 2 A top view of an embodiment of a base plate of a base.

[0013] Figure 4 yes Figure 3 End view of the base plate.

[0014] Figure 5 yes Figure 2 A top view of an embodiment of the base position drive plate.

[0015] Figure 6 yes Figure 5 Side view of the driver plate in position.

[0016] Figure 7 yes Figure 3 A side view of an embodiment of a base plate and a position drive plate support carried on the base plate.

[0017] Figure 8 Yes Figure 7 The base plate and the position driving plate support and the position driving plate support carried on the position driving plate support Figure 5 2 is a side view of an embodiment of a base subassembly of a position drive plate.

[0018] Fig. 9 yes Figure 8 A perspective view of the base subassembly.

[0019] Fig.10 yes Figure 2 A top view of an embodiment of a carrier plate of a carrier.

[0020] Fig.11 yes Fig.10 End view of the carrier plate.

[0021] Fig.12 Yes Fig.10 A bottom view of another carrier subassembly embodiment of a carrier plate and a position receiver carried by the carrier plate.

[0022] Fig.13 A sensing electrode is provided which is supported by a guard electrode. Fig.12 End view of the receiver in position.

[0023] Fig.14 A sensing electrode comprising a sensing electrode surrounded by a portion of a guard electrode Fig.12 Bottom view of the receiver in position.

[0024] Fig.15 It passes through Fig.12 Schematic cross-sectional view of a position receiver showing a guard electrode having a central coaxial shield and a sensing electrode having a central coaxial conductor extending through the central coaxial shield.

[0025] Fig.16 yes Fig.12 A top view of the carrier subassembly.

[0026] Fig.17 yes Fig.16 A top view of a carrier subassembly showing a sensor cable coupled to a position receiver.

[0027] Fig.18 yes Figure 2 A perspective view of an embodiment of a frame of an armature of an actuator.

[0028] Fig.19 yes Fig.18 End view of the frame.

[0029] Fig. 20 Yes Fig.18 The armature frame and Fig.10 An exploded perspective view of an embodiment of a carrier subassembly of a carrier plate.

[0030] Fig.21 yes Fig. 20 End view of the carrier subassembly showing the legs of the armature frame pinned to the carrier plate.

[0031] Fig. 22 yes Figure 1An exploded upper front perspective view of a nanopositioner of , showing a carrier movably coupled to a base, an armature configured to be fixed to the carrier, and a stator configured to be secured to the base to movably capture the armature relative to the base, and including a piezoelectric actuator.

[0032] Fig.23 yes Figure 1 End view of the nanopositioner.

[0033] Fig.24 yes Figure 1 A top front perspective view of a nanopositioner showing the bearing positioner coupled to a carrier.

[0034] Fig.25 yes Figure 1 A perspective cross-sectional view of a nanopositioner taken through the legs of the armature frame and through a portion of the stator to illustrate the closed-loop mechanical and instrumented connection of the carrier to the base via the actuator and the variable area capacitive position sensor comprising a position driver and a position receiver.

[0035] Fig.26 yes Figure 1 A three-dimensional cross-sectional view of a nanopositioner taken through its longitudinal center.

[0036] Fig. 27 yes Fig. 22 A top view of an embodiment of a preload plate for a piezoelectric actuator.

[0037] Fig.28 is carried in Fig. 27 A top view of an embodiment of a base or primary piezoelectric element within a recess of a preload plate.

[0038] Fig.29 is carried in Fig.28 Top view of an embodiment of a piezoelectric element on a foil.

[0039] Fig.30 is carried in Fig.29 Top view of an embodiment of an auxiliary piezoelectric element on a foil.

[0040] Fig.31 is carried in Fig.30 A top view of an embodiment of a sliding bearing element on an auxiliary piezoelectric element.

[0041] Fig.32 yes Fig. 22 Schematic side view of an embodiment of a piezoelectric actuator.

[0042] Fig.33 Shown in a stationary state Fig. 22 Electrical schematic side view of an embodiment of a piezoelectric actuator.

[0043] Fig.34 It is shown in the power-on state Fig. 22 Electrical schematic side view of an embodiment of a piezoelectric actuator. DETAILED DESCRIPTION

[0044] In general, the apparatus will be described using one or more examples of illustrative embodiments of a nanopositioner including one or more examples of illustrative embodiments of a piezoelectric actuator. The example embodiments will be described with reference to use in a cryogenic environment. However, as the description proceeds, it should be understood that the embodiments are useful in many different applications and can be implemented in many other environments including room temperature environments and other non-cryogenic environments.

[0045] Specifically refer to the accompanying drawings, Figure 1 An illustrative embodiment of a nanopositioner 10 is shown that can be used in a cryogenic environment, or can be used in any other environment suitable for use with a nanopositioner. The nanopositioner 10 can be driven by a slip-viscosity piezoelectric actuator, a magnetoresistive actuator, or any other actuator suitable for use with the nanopositioner 10. Externally instrumented nanopositioners (e.g., those that use an interferometer external to the nanopositioner) are capable of achieving position repeatability on the nanometer scale when they operate. And in cryogenic environments, conventional internally instrumented nanopositioners are low energy because they are capable of achieving position repeatability of approximately two microns (e.g., 1-3 microns), making them merely micropositioners. Notably, the internal position instrumentation of conventional nanopositioners typically includes a resistive sensing configuration, such as a reverse potentiometer, for measuring the position of a carrier relative to a base. In contrast, the nanopositioners disclosed herein can be internally instrumented, but are configured to provide position repeatability of approximately 200 nanometers (e.g., 100-300 nanometers), making them true nanopositioners in cryogenic environments. As used herein, the term "cryogenic" refers to temperatures of approximately 20 mK to 100 K, although many cryogenic experiments are typically performed at or around 4 K.

[0046] Reference Figure 2, nanopositioner 10 includes a base 12, a carrier 14 movably carried relative to base 12, and an actuator 16 operatively coupling carrier 14 to base 12. As described in further detail below, nanopositioner 10 may also be internally equipped with internal position instrumentation operatively carried between base 12 and carrier 14. Base 12 may be used to mount nanopositioner 10 to other devices or equipment, and to support other portions of nanopositioner 10, such as carrier 14. Carrier 14 may be used to carry sample material or product, an SPM instrument, a cryogenic research instrument, or anything else suitable for use with nanopositioner 10. Actuator 16 moves carrier 14 relative to base 12.

[0047] Base 12 includes a base plate 18, a position driver 20 carried by base plate 18 and which is part of the internal position instrumentation, and a set of base bearings 22 carried by base plate 18. Base 12 may include the drive portion of nanopositioner 10 that exerts a motive force on carrier 14 but remains relatively stationary.

[0048] Reference Figure 3 and Figure 4 , the base plate 18 can have a base bottom 24 and a base top 28, the base bottom 24 having a bottom surface 26, the base top 28 having a position driver mounting surface 30 and a base bearing mounting surface 32 outside the position driver mounting surface 30. The base plate 18 can also have a base end 34 and a base side 38, the base end 34 having a base end surface 36 extending between the base bottom 24 and the base top 28, and the base side 38 having a base side surface 40 extending between the base bottom 24 and the base top 28 and between the base end 34. The base plate 18 can also include, for example, in the base end surface 36 (see Figure 4 ) and / or a toe clamp recess 42 in the base side surface 40 for receiving a toe clamp (not shown) during production of the base plate 18. The base plate 18 has an actuator eyelet 44 therethrough that can extend between the bottom surface 26 and the position driver mounting surface 30. The base plate 18 can also have a carrier bearing clearance surface 46 that is outboard of the position driver mounting surface 30 and can be recessed relative to the position driver mounting surface 30. The base bearing mounting surface 32 can be coplanar with the position driver mounting surface 30. The base plate 18 can be provided with suitable mounting holes 48 (which can be threaded), and / or a toe clamp (not shown) to facilitate mounting of the nanopositioner 10. The base plate 18 can be constructed of titanium or any other suitable non-ferrous metal.

[0049] Now refer to Figure 5 and Figure 6, the position driver 20 includes a drive plate 50 carrying a set of drive electrodes 52. The set of drive electrodes 52 may include complementary, reverse, interdigitated or otherwise corresponding first electrodes 52a and second electrodes 52b. The corresponding electrodes may be triangular elements, which may include interdigitated triangular elements, which may include guidon-shaped elements 52a forming a triangular space and triangular or triangular elements 52b in the triangular space formed by the guidon-shaped elements 52a. As used herein, the term "triangular" includes elements that are primarily triangular in shape even if they are not perfect triangles. Interdigitated triangular elements may be superior to the use of identical triangular elements with adjacent hypotenuses for causing tilt.

[0050] Now refer to Figure 7 and Figure 8 , the position driver 20 may also include a position driver support 54 that carries the position driver plate 50 and is directly coupled to the position driver mounting surface 30 of the base plate 18. The support 54 may be constructed of titanium or any other suitable non-ferrous metal. Referring again to Figure 8 and Fig. 9 , the position driver 20 may be carried by the position driver mounting surface 30 on the top of the base plate 18, and may include a position driver plate 50 bridging over the actuator eyelet 44 of the base plate 18 of the base 12. The position driver plate 50 may be constructed of ceramic or other suitable non-conductive material, and the drive electrodes may be constructed of a copper layer on the driver plate and a gold layer on the copper layer.

[0051] Refer again Figure 2 The above-mentioned set of pedestal bearings 22 can be carried by the pedestal bearing mounting surface 32 of the top 28 of the pedestal plate 18, and can be carried on the outside of the above-mentioned set of drive electrodes 52 of the position drive plate 50 ( Figure 5 ). The set of pedestal bearings 22 may include V-groove rails, ball bearings carried between the V-groove rails, ball retaining spacers for retaining the ball bearings to the V-groove rails, and spacer creep stops. The V-groove rails may be made of polished ceramic, zirconium oxide, etc. The ball retaining spacers may be made of polyetheretherketone or any other suitable thermoplastic polymer material.

[0052] Continue to refer to Figure 2 , carrier 14 includes a carrier plate 56, a position receiver 57 carried by carrier plate 56 and being another part of the internal position instrument, and a set of carrier bearings 58 carried by carrier plate 56. Carrier 14 may be a driven portion of nanopositioner 10 that responds to a motive force applied from or via base 12 and moves in response to the motive force.

[0053] Now refer to Fig.10 and Fig.11 , the carrier plate 56 may have a carrier top 60 and a carrier bottom 64, the carrier top 60 having a top surface 62, the carrier bottom 64 having a bottom or position receiver mounting surface 66 and a carrier bearing mounting surface 68 outboard of the position receiver mounting surface 30, the bottom or position receiver mounting surface 66 corresponding to and facing the position driver mounting surface 30 of the top 28 of the base plate 18 of the base 12. The carrier plate 56 may also have a carrier end 70 and a carrier side 74, the carrier end 70 having a carrier end surface 72 extending between the carrier bottom 64 and the carrier top 60, and the carrier side 74 having a carrier side surface 76 extending between the carrier bottom 64 and the carrier top 60 and between the carrier end 70. The carrier plate 56 may also include, for example, in the carrier end surface 72 (see Figure 1 ) and / or a toe clamp recess 78 in the carrier side surface 76 for receiving a toe clamp (not shown) during production of the carrier plate 56. The carrier plate 56 may also have a pedestal bearing clearance surface 80 outside of the position receiver surface 66.

[0054] Refer again Figure 1 and Figure 2 , the carrier 14 may also include a carrier bearing adjustment flange 82 at the side 74 of the carrier plate 56, which extends toward the base 12 and carries the carrier bearing 58 at its inner surface. The flange 82 can be made of titanium or any other suitable non-ferrous metal. The outer side position of the carrier bearing 58 in contact with and / or adjacent to the flange 82 provides a good thermal path, which can be, for example, coupled to a high purity aluminum belt (not shown), etc., which can be directly or indirectly coupled to a low temperature base plate (not shown) via a low temperature conductor (not shown). Such a belt can be fastened to a threaded adjustment hole 84 in the bearing flange 82 of the carrier 14. If the flange 82 is no longer needed for such a thermal path or other purposes, the flange 82 can be loosened from the carrier plate 56, thereby exposing the side of the bearing 58. Additionally, carrier plate 56 may be provided with suitable mounting holes 48, which may be threaded and / or have toe clamps (not shown), to facilitate mounting other equipment to nanopositioner 10. Carrier plate 56 may be constructed of titanium or any other suitable non-ferrous metal.

[0055] Now refer to Fig.12 The position receiver 57 can be carried by the position receiver mounting surface 30 at the bottom of the carrier plate 56 and includes a plurality of drive electrodes 52a, 52b (operably coupled to the plurality of drive electrodes 52a, 52b) as described above. Fig. 9 ) of the driven or sensing electrode 88. Now referring to Figures 13 to 15 , the position receiver 57 may include a guard electrode 90 having a portion that may surround the sensing electrode 88. The guard electrode 90 may have a central coaxial shield 92, and the sensing electrode 88 may have a central coaxial conductor 94 extending through the central coaxial shield 92 of the guard electrode 90. The central coaxial conductor 94 may be Fig.16 As seen in the plan view, and Fig.17 Shown in FIG. 1 as being connected to sensor cable 96 .

[0056] Refer again Figure 2 , the sensing electrode 88 and the above-mentioned set of drive electrodes 52 can at least partially form an area change sensor or a variable area capacitive position sensor. Capacitance is a function of the surface area of ​​the opposing surfaces divided by the distance between the opposing surfaces, where conventional capacitive position sensing generally involves measuring the change in distance between opposing surfaces of fixed area. However, for the currently disclosed internal position instrument, capacitive position sensing involves measuring the change in the surface area portion of the drive electrode relative to the fixed surface area of ​​the sensing electrode, where the distance between the drive electrode and the sensing electrode is fixed, which will be further described below.

[0057] Overall reference Figure 2 , Figure 5 and Fig.12 , the sensor includes a differential electrode configuration. Figure 5 The driving electrode configuration includes a concave first electrode 52a and a convex second electrode 52b spaced apart from the first electrode 52a. The electrodes 52a, 52b are coupled to the base 12 and can be driven by high-frequency sine waves that are 180 degrees out of phase with each other. Fig.12 , the electrode configuration also includes a common or single third sense electrode 88 attached to the carrier 14. The interdigitated configuration of electrodes 52a, 52b can make position sensing insensitive or less sensitive to tilt between the sense electrodes 88 and the drive electrodes 52. Otherwise, for example, tilting of the position drive plate 50 relative to the carrier 14 can cause the sense electrodes 88 to be excessively affected by the drive electrodes 52, which have a surface area 50 that is relatively more tilted relative to the carrier 14. The nanopositioner 10 can be configured to invert the electrodes so that the first and second electrodes can be carried by the carrier 14, and the third electrode can be carried by the base 12.

[0058] The overlapping area from the first electrode 52a to the third electrode 88 and from the second electrode 52b to the third electrode 88 creates a variable differential capacitor that can then be measured and used to determine the position of the carrier 14 relative to the base 12. When the sense electrode 88 is centered on the first drive electrode 52a and the second drive electrode 52b, the system is balanced so that the sensor reports a zero signal. If the sense electrode 88 is offset from the centered position toward the first electrode 52a, it will report a non-zero waveform with the phase of the first electrode 52a corresponding to the area of ​​the offset position.

[0059] The internal position instrument including the position driver 20 and / or the position receiver 57 can be configured so that there can be a gap of 50 microns to 100 microns between the drive electrode 52 and the sensing electrode 88, including all ranges, sub-ranges, endpoints and values ​​within this range. The gap can be maintained within plus or minus one micron. In order to achieve good performance of this type of sensor, specific dimensions of the nanopositioner 10 are provided to form a precise gap between the drive electrode 52 and the sensing electrode 88 during initial manufacturing and when in use. As described below with respect to the method of producing the nanopositioner 10, the gap can be initially set with high precision. In addition, the bearings 22, 58 can constrain the movement in a manner that causes the gap variation to be small within the end-to-end range of motion of the carrier 14 relative to the base 12, and maintain the consistency of the gap to achieve good repeatability of the position measurement.

[0060] Continue to refer to Figure 2 , the set of carrier bearings 58 may be carried by the carrier bearing mounting surface 84 of the bottom 64 of the carrier plate 56 and operatively coupled to the set of pedestal bearings 22 of the base 12. The set of carrier bearings 58 may be carried on the outside of the position receiver 57 and may include a V-groove guide to cooperate with the ball bearing and spacer creep stop of the set of pedestal bearings 22.

[0061] The set of pedestal bearings 22 and the set of carrier bearings 58 may be linear precision guides available from PM Linear of the Netherlands. Each bearing guide has a reference plane formed by a mounting surface for mounting to a respective one of the pedestal 12 or carrier 14, and a bearing plane corresponding to and extending through the center or lowest point of the V-shaped groove of the bearing guide 62. The bearing manufacturer can maintain parallelism between the reference plane and the bearing plane to less than two microns.

[0062] Reference Figure 2, the actuator 16 includes a stator 98 fixed relative to the base 12, and an armature 100 operatively coupled to the stator 98, the armature 100 extending through the actuator aperture 44 of the base plate 18 of the base 12 and coupled to the carrier 14. As used herein, the term "stator" includes, for example, a driving portion of the actuator 16 that transmits or applies motive force but remains relatively fixed, and the term "armature" includes, for example, a driven portion of the actuator 16 that receives motive force or responds to motive force and moves in response to the motive force.

[0063] The stator 98 of the actuator 16 can be removably coupled to the bottom surface 26 of the base 12 to facilitate removal and replacement of at least a portion of the stator 98. This may be contrasted with typical conventional nanopositioners that typically have a stator that is non-removably fixed to the base. As used herein, the term "non-removably" means that the stator 98 cannot be removed from the base 12 without permanent damage to some portion of the stator 98. For example, many conventional nanopositioners have stators that are bonded to the base with epoxy, where the epoxy must be melted, cut, or otherwise removed, and some mounted portion of the stator that is in contact with the epoxy must be replaced.

[0064] The presently disclosed stator 98 may include a biasing element coupled to the base 12, such as a leaf spring 102 secured to the base 12 (e.g., the bottom surface 26 of the base 12). The leaf spring 102 may be constructed of beryllium copper, other copper alloys, or any other suitable non-ferrous metal. The stator 98 may also include a preload plate 104 positioned between the leaf spring 102 and the armature 100, a ball bearing pivot 106 that may be carried by the leaf spring 102 and in contact with the preload plate 104, a shear piezoelectric stack 108 that may be carried between the preload plate 104 and the armature 100, and a sliding bearing element, such as a disk 110, that may be secured to the shear piezoelectric stack 108 and in sliding contact with the armature 100. The preload plate 104 may be made of or any other suitable ceramic. Ball bearing pivot 106 may include two or any other suitable number of ball bearing elements, which may be composed of ceramic, silicon nitride, etc. Sliding bearing element 110 may be polished sapphire. Thus, compared to conventional nanopositioners that typically require disassembly of carrier 14 from base 12 to remove and replace piezoelectric stack 108, the presently disclosed mounting configuration of stator 98 relative to base 12 may facilitate removal and replacement of piezoelectric stack 108 without having to disassemble carrier 14 from base 12. In addition, some conventional nanopositioner designs do not facilitate removal and replacement of piezoelectric stack 108, necessitating removal and replacement of the entire nanopositioner 10. The presently disclosed configuration may provide a significant economic improvement over such conventional designs.

[0065] Reference Figures 18 to 21, the armature 100 of the actuator 16 may be trapezoidal. For example, the armature 100 may include a platform 112 and legs 114 extending away from the platform 112 toward the carrier 14 and coupled to the carrier 14, for example, pinned into the carrier plate 56 of the carrier 14. Fig. 22 , the armature 100 may include a sliding bearing element, such as a plate 116, which may be carried by the platform 112, for example, on the outer surface of the platform. The sliding bearing element 116 may be a polished sapphire or alumina member, which may be rectangular in shape. In another embodiment, the armature 100 may be constructed of beryllium copper, wherein the outer surface of the platform 112 may be polished to a mirror finish, and wherein the armature 100 need not include a plate carried on the platform 112. Additionally, the outer surface of the platform 112 may be gold plated to further reduce the coefficient of friction, or may be treated with a lubricant (e.g., tungsten disulfide).

[0066] Continue to refer to Fig. 22 , the actuator 16 may include a custom designed and / or constructed actuator, or a commercially available actuator. In a slip-viscous piezoelectric actuator embodiment, the capacitance of the actuator 16 is preferably less than 2 microfarads, more specifically, between 5 and 40 nanofarads, including all ranges, subranges, endpoints and values ​​within that range. The piezoelectric stack 108 may include a base or main piezoelectric element 118, an auxiliary piezoelectric element 120 carried on the base piezoelectric element 118, and a conductive foil 122 between the main piezoelectric element 118 and the auxiliary piezoelectric element 120. The conductive foil 122 may be made of copper or gold, silver, bronze, lead, nickel silver, beryllium copper, tungsten, tantalum or any other material suitable for use as a conductive foil. A conductor (not shown) may be coupled to the copper foil 122 at the positive terminal of the conductor. The sliding bearing element 110 may be bonded to the auxiliary piezoelectric element 120 with epoxy. Piezoelectric elements can be made of PZT (lead zirconate titanate) or lithium niobate (LiNbO 3 ) or any other suitable piezoelectric material. The piezoelectric element may be a CSAP03 noliac shear plate actuator having a maximum operating voltage of + / -320V, a corresponding free travel of 1.5 microns, and a capacitance of 3.32 nF, available from CTS Ceramics of Denmark, or similar products available from Physik Instrumente or any other suitable supplier. A specific piezoelectric actuator will be described in further detail below with reference to a method for producing the piezoelectric actuator.

[0067] In operation, nanopositioner 10 is controlled in any suitable manner, for example, to apply power to actuator 16 and internal position instrumentation, and to process position sensor signals. One of ordinary skill in the art will recognize that control of nanopositioner 10 may be facilitated by one or more processors, memory coupled to the processor(s), and any suitable instructions executed by the processor(s) and data stored in the memory. Such facilitating subject matter is not subject of the present disclosure, and any suitable such subject matter may be used.

[0068] In a slip-viscous piezoelectric actuator embodiment, the piezoelectric stack 108 can be powered so as to push the sliding bearing element 110 relatively quickly over the sliding bearing sheet 116 in a periodic manner and pull the sliding bearing sheet 116 relatively slowly via fixed friction contact with the disk 110 to achieve the desired displacement of the carrier 14 relative to the base 12. For example, in a slip-viscous piezoelectric actuator embodiment, an actuator power supply (not shown) can include a DC power supply or any other power supply suitable for providing a voltage level compatible with piezoelectric limitations, and a waveform generator connectable to the power supply, which can generate a periodic signal, such as a sawtooth waveform, an S-shaped waveform, an exponential waveform, and any other waveform of any other shape suitable for driving a piezoelectric motor. The output power provided by the power supply can be between 10 and 2000 volts, including all ranges, subranges, endpoints, and values ​​within the range, and can be between 0.001 and 0.5 amperes, including all ranges, subranges, endpoints, and values ​​within the range. In a more specific example, the power supply can provide 50 to 600 volts, including all ranges, subranges, endpoints and values ​​within that range, and 0.1 to 0.3 amps, including all ranges, subranges, endpoints and values ​​within that range. One of ordinary skill in the art will recognize that the parameter values ​​of the motor drive 16 are different between ambient temperature (e.g., 65 to 80 degrees Fahrenheit) and low temperature. For example, at ambient temperature, the motor drive can operate between 100 Hz and 2 kHz, including all ranges, subranges, endpoints and values ​​within that range, and can provide 30 volts to 200 volts, including all ranges, subranges, endpoints and values ​​within that range, and 0.1 to 0.3 amps, including all ranges, subranges, endpoints and values ​​within that range. In contrast, at low temperatures, the same motor drive may operate between 100 kHz and 4 kHz, including all ranges, subranges, endpoints and values ​​therein, and provide 200 to 300 volts, including all ranges, subranges, endpoints and values ​​therein, and 0.1 to 0.3 amps, including all ranges, subranges, endpoints and values ​​therein.

[0069] Likewise, the internal position instrument can be powered in any manner suitable for use with a nanopositioner, particularly a cryogenic nanopositioner. For example, a high precision low voltage can be transmitted to the instrument in any suitable manner. And the signals from the instrument can be received by a preamplifier and sent to, for example, a processor and FPGA, where they can be demodulated and correlated with a function that outputs position in user-specified length units.

[0070] As a result, the nanopositioner 10 is capable of performing with a position repeatability of approximately 200 nanometers (e.g., 100-300 nanometers). Thus, the performance of the nanopositioner 10 may be three orders of magnitude better than that obtainable from currently available in-house instrumented nanopositioners. Thus, the presently disclosed nanopositioner 10 may represent a new performance standard in the industry.

[0071] According to various embodiments described above and shown in the accompanying drawings, an exemplary method of producing a nanopositioner 10 includes several steps. The method may or may not include all of the disclosed steps, or may be processed sequentially or in the specific order discussed, and the method currently disclosed may include any ordering, overlapping, or parallel processing of these steps.

[0072] The method may include processing the top and bottom surfaces of the nanopositioner base plate 18 to be parallel to each other within a base plate tolerance, such as between 0 and 2 microns, including all ranges, subranges, endpoints and values ​​within this range, but preferably less than 1 micron. For example, the processing step may include surface grinding of the top and bottom surfaces, or lapping, high precision milling, or any other suitable material removal process. In the surface grinding example, the feed rate or stepover may be about 2 mm, and the base plate may be clamped to the steel plate supported on the magnetic plate by using a toe clamp (not shown) fastened to the steel plate and clamped to the toe clamp pocket 42 of the base plate 18.

[0073] The method may include processing the top and bottom surfaces 82 of the nanopositioner carrier plate 56 to be parallel to each other within a carrier plate 56 tolerance, such as between 0 and 2 microns, including all ranges, subranges, endpoints, and values ​​within that range, but preferably less than 1 micron. For example, the processing step may include surface grinding of the top and bottom surfaces, or lapping, high precision milling, or any other suitable material removal process. In the surface grinding example, the feed rate or step size may be about 2 mm, and the carrier plate may be clamped to a steel plate supported on a magnetic plate by using a toe clamp (not shown) fastened to the steel plate and clamped to the toe clamp pocket 42 of the carrier plate 56.

[0074] The method can include mounting the actuator armature 100 onto the bottom surface 82 of the carrier plate 56. For example, the carrier plate 56 can be positioned upside down and the legs of the actuator armature 100 can be inserted into corresponding pin holes on the carrier plate 56.

[0075] The method may include processing the bottom surface of the platform 112 of the armature 100 to be parallel to the top surface 62 of the carrier plate 56 within the tolerance of the armature 100, such as between 0 and 2 microns, including all ranges, subranges, endpoints and values ​​within this range, but preferably less than 1 micron. For example, the processing step may include surface grinding of the bottom surface of the platform 112, or lapping, high precision milling or any other suitable material removal process. In the surface grinding example, the feed rate or step size may be about 2 mm on the slow axis; and the fast axis feed rate may be 100-500 mm / s.

[0076] The method may include removing the actuator armature 100 from the carrier plate 56 after the armature surface grinding step. For example, the legs 114 of the actuator armature 100 may be removed from corresponding pin holes on the carrier plate 56, such as by simply lifting the armature 100 away from the carrier plate 56.

[0077] The method may include mounting the position receiver 57 to the bottom surface 82 of the carrier plate 56. For example, the position receiver 57 may be adhered to the carrier plate 56, for example, using epoxy, or with any other suitable adhesive, or by coupling the position receiver 57 to the carrier plate 56 with fasteners or in any other suitable manner. Fig.12 The position receiver 57 shown is applied to the bottom surface 82 of the carrier plate 56 .

[0078] The method may include mounting the position drive plate support 54 onto the top surface of the base plate 18. For example, the drive plate support 54 may initially have the same thickness and may be coupled to the top surface of the base plate 18, for example, using epoxy or any other suitable adhesive or using fasteners or in any other suitable manner.

[0079] The method may include mounting the position drive plate 50 to the standoff 54 on the top surface of the base plate 18. For example, the position drive plate 50 may be coupled to the standoff 54, such as using epoxy or any other suitable adhesive or using fasteners or in any other suitable manner.

[0080] The method may include measuring the parallelism of the position drive plate 50 to obtain parallelism measurements of the drive plate 50, for example, at opposite ends of the drive plate 50. For example, an interferometer may be used to measure parallelism.

[0081] The method may include using the parallelism measurement to process the top surface of the drive plate support 54 so that the top surface of the drive plate 50 is parallel to the bottom surface 26 of the base plate 18 within a drive plate tolerance, for example, between 0 and 2 microns, including all ranges, subranges, endpoints and values ​​within this range, but preferably less than 1 micron. For example, the processing step may include surface grinding, or lapping, high precision milling or any other suitable material removal process of the top surface of the support 54. Of course, the top surface of the support 54 can be processed differently or to different degrees depending on the degree to which the support 54 initially deviates from parallel to each other.

[0082] The method may include mounting a plurality of sets of bearings 22 onto the top surface 162 of the base plate 18 and the bottom surface 82 of the carrier plate 56. The plurality of sets of bearings 22 may include a plurality of sets of linear bearings. For example, the plurality of sets of bearings 22 may be fastened to the base plate 18 and the carrier plate 56 via fasteners extending through the plates 18, 56 and into the plurality of sets of bearings 22, 58, respectively. The pedestal bearing guides may be spaced apart from each other according to specification using one or more metering blocks and then fastened to the base 12. The carrier bearing guides may be spaced apart from each other slightly larger than specification, for example, between 100 and 400 microns, including all ranges, sub-ranges, endpoints and values ​​within this range, and then fastened to the carrier 14. Although the pedestal bearings 22 may be fully and tightly fastened to the base 12, the carrier bearings 58 may be loosely fastened to the carrier plate 56 to allow for adjustment thereof as described below.

[0083] The method may include assembling the carrier 14 to the base 12. Positioning the carrier 14 to the base 12 so that the bearing rails are opposite each other, then initially inserting the bearing spacer between the bearing rails, and assembling each bearing ball 64 between the bearing rails, and advancing the bearing spacer between the bearing rails, one ball at a time, until all balls have been assembled.

[0084] For example, the method may include placing multiple sets of bearings 22 into appropriate engagement with each other. Fig.24, the sets of carrier bearings 58 may be moved laterally toward the central longitudinal axis A of the nanopositioner 10 into proper engagement with the sets of base bearings 22. For example, adjustment screws 124 may be inserted through corresponding threaded adjustment holes 84 on the bearing flange 82 of the carrier 14 and threaded into abutting engagement with the sets of carrier bearings 58 to move the carrier bearings 58 and ensure proper contact of the bearing balls and the V-grooves. The adjustment screws may be threaded simultaneously to set the bearings 58 and may then be removed. Thereafter, the carrier bearings 58 are fully and tightly fastened to the carrier plate 56. To allow for some play in the carrier bearings 58 relative to the carrier plate 56, the carrier bearing fastener holes on the carrier plate 56 may be slightly oversized, but it is contemplated that typical fastener to fastener hole tolerances will facilitate adjustment of the carrier bearings 58 by around 10 to 100 microns.

[0085] The method may include mounting the actuator armature 100 to the carrier plate 56. For example, a portion of the actuator armature 100 may be inserted through the actuator armature eyelet 44 on the base plate 18. For example, the legs of the actuator armature may extend through the eyelet 44 and be inserted into corresponding holes on the bottom surface 82 of the carrier plate 56, so that the actuator armature 100 spans the position drive plate 50 with a gap therebetween and does not contact the sensing electrode 88. Thus, the actuator armature 100 spans the position driver 20 and the position receiver 57 of the internal position instrument, so that the actuator 16 and the internal position instrument are mechanically separated relative to each other. Thus, the internal position instrument may be installed, and then the actuator 16 may be installed separately, thereby facilitating removal and replacement of the actuator 16.

[0086] The method may include coupling a sliding bearing element 110 to a platform 112 of the actuator armature 100. For example, the sliding bearing element may be a sheet 116 that may be epoxied or otherwise adhered or otherwise coupled to the platform 112 in any suitable manner. Preferably, this step is performed after the actuator armature 100 is assembled to the carrier 14.

[0087] The method may include mounting the actuator stator 98 to the base plate 18 to capture the actuator armature 100 between the actuator stator 98 and the carrier plate 56. For example, the leaf spring 102 of the actuator stator 98 may be fastened to the bottom surface 26 of the base plate 18 such that the disk 110 of the stator 98 contacts the leaf 116 of the actuator armature 100. Fig. 22 The illustrated piezoelectric actuator can be produced by the following method of producing a piezoelectric actuator according to the present disclosure.

[0088] Now refer to Fig. 27, the preload plate 104 (or "piezoelectric stack carrier") includes a base 126 or mounting surface and an oppositely disposed piezoelectric surface 128. The preload plate 104 may also include a piezoelectric pocket 130 in the piezoelectric surface 128 for carrying the piezoelectric stack 108, the piezoelectric pocket 130 having a piezoelectric support surface 132 at the bottom of the pocket 130, on which the piezoelectric stack 108 is supported. The piezoelectric pocket 130 may be formed by a surrounding wall 134 extending away from the piezoelectric support surface 132, the surrounding wall 134 may include at least three complete walls and at least one fourth wall, the fourth wall may have a lateral slot 136 extending laterally therethrough. The pocket 130 may be rectangular, such as a square as shown, and may include semicircular cutouts 138 at the corners of the piezoelectric pocket 130. The preload plate 104 can have any suitable number of sides 140a-f, such as four sides, five sides, or, as shown, six sides. The fifth and sixth sides can be beveled and can connect the second and third sides and the third and fourth sides.

[0089] In addition, the preload plate 104 may include one or more foil tab slots 142a-c that communicate with the piezoelectric pocket 130 and extend through one or more sides 140a-f of the preload plate 104. In the illustrated embodiment, the first foil tab slot 142a may extend orthogonally through the first side 140a (e.g., at the twelve o'clock position), the second foil tab slot 142b may extend orthogonally through the second side 140b (e.g., at the nine o'clock position), and the third foil tab slot 142c may extend orthogonally through the third side 140c (e.g., at the six o'clock position). The preload plate 104 may also include a foil pocket that may include one or more of the foil tab slots 142a-c through at least one surrounding wall 134 in addition to a portion of the piezoelectric pocket 130. The preload plate 104 may include a through hole 144 proximate the third side 140c to facilitate routing of a negative lead or wire (not shown) therethrough.

[0090] Continue to refer to Fig. 27, the preload plate 104 may also include lead or wire routing features. For example, the preload plate 104 may include a central through hole 146 extending through the preload plate 104 at a central location of the recess 130, between the base 126 and the piezoelectric side portions 140a-f, and communicating with the base 126 and the piezoelectric support surface 132. The preload plate 104 may also include a channel 148 on the piezoelectric support surface 132 and communicating with the through hole 144, and extending from the through hole 144 through the lateral slot 136 to the fourth side portion 140d of the preload plate 104. The preload plate 104 may be configured to carry a piezoelectric stack 108, which may be retained by the surrounding wall 134 of the preload plate 104, as described below.

[0091] Now refer to Fig.28 , a base or main piezoelectric element 118 is assembled into and carried in the piezoelectric pocket 130 of the preload plate 104. For simplicity, the term "piezoelectric body" may be used interchangeably with "piezoelectric element" herein. The main piezoelectric body 118 has major opposing faces 151, through which the normal axis L of the piezoelectric stack 108 extends, and major side portions 152, which extend between the major opposing faces 151 and form a lateral outer periphery having a geometry that can match the perimeter geometry of the pocket 130. For example, the main piezoelectric body 118 can be rectangular, and more specifically, can be square or square. For example, the main piezoelectric body 118 can have a major vertex 154 extending between the major opposing faces 151 and forming a major corner between the major side portions 152, and a major slope 155 (two are shown on the same side) extending between the major opposing faces 151 and oriented in a first orientation, and the major vertex 154 can overlap with the corresponding semicircular cutout 138 of the preload plate 104. The main piezoelectric body 118 can cover at least a portion of the through hole 144 and the lateral slot 136 of the preload plate 104. The main piezoelectric body 118 can be a shear piezoelectric body that can be coupled to the preload plate 104 via epoxy or any other suitable adhesive, or coupled in any other suitable manner. In this position, a wire (not shown) can be inserted into the through hole 144 through the lateral slot 136 and then coupled to the piezoelectric body 118, for example, via soldering, spot welding, or in any other suitable manner.

[0092] Now refer to Fig.29, the conductive foil 122 is assembled to and carried on the main piezoelectric 118 within the piezoelectric pocket 130 of the preload plate 104. As used herein, the term "foil" includes any foil-like or plate-like component with a thickness less than the thickness of each of the main piezoelectric 118 and the auxiliary piezoelectric 120. The foil 122 may include a central body 158 covering a central portion of the main piezoelectric 118, and at least one tab extending laterally away from the central body 158. In the illustrated embodiment, the foil 122 includes a first tab 160a, which may extend orthogonally away from the central body 158 and may be carried in a first foil tab slot 142a of the preload plate 104, a second tab 160b, which may extend orthogonally away from the central body 158 and may be carried in a second foil tab slot 142b of the preload plate 104, and a third tab 160c, which may extend orthogonally away from the central body 158 and may be carried in a third foil tab slot 142c of the preload plate 104. The third tab 160c may be beveled as an orientation feature to help the assembler properly orient the foil 122 relative to the preload plate 104. For example, the foil bevel 162 may correspond to the preload plate bevel 155 or beveled sides to help orient the conductive foil 122 relative to the preload plate 104. The foil 122 may also include a fourth tab 160d that may be wider than one or more of the other tabs. One or more of the tabs may include an eyelet 46 that may facilitate manipulation with tweezers or any other suitable tool. The foil 122 may be coupled to the main piezoelectric 118, for example, via a conductive epoxy or any other suitable adhesive, or in any other suitable manner. One or more of the tabs 160a-c may rest on one or more corresponding surfaces of the plate 104 forming corresponding tab slots 142a-c.

[0093] Now refer to Fig.30, a second or auxiliary piezoelectric body 120 is assembled to and carried on the foil 122 and at least partially in the piezoelectric pocket 130. The auxiliary piezoelectric body 120 has auxiliary opposing faces 168 through which the longitudinal axis L of the piezoelectric stack 108 extends and auxiliary side portions 170 extending between the auxiliary opposing faces 168 and forming a lateral outer periphery having a geometry that can match the perimeter geometry of the pocket 130. For example, the auxiliary piezoelectric body 120 can be rectangular, and more specifically, can be square or square. For example, the auxiliary piezoelectric body 120 can have an auxiliary vertex 172 extending between the auxiliary opposing faces 168 and forming an auxiliary corner between the auxiliary side portions 170, and an auxiliary inclined surface 174 (two are shown on the same side) extending between the auxiliary opposing faces 168 and oriented in a second orientation opposite to the first orientation of the main piezoelectric body 118, and the auxiliary vertex 172 can overlap with the corresponding semicircular cutout 138 of the preload plate 104. The oppositely oriented inclined surfaces indicate the correct polarity of the piezoelectric elements relative to each other. The auxiliary piezoelectric body 120 can be coupled to the foil 122, for example, via a conductive epoxy or any other suitable adhesive, or coupled in any other suitable manner.

[0094] Thus, the foil 122 is disposed between facing instances of the primary opposing faces 151 and the auxiliary opposing faces 168 of the primary piezoelectric element 118 and the auxiliary piezoelectric element 120. One or more tabs of the foil 122 may extend laterally outward beyond the peripheral edge of the piezoelectric elements 118, 120 to form a lead or wire connection point outside the piezoelectric body, thereby reducing the line of sight between the positive and negative electrodes and the accompanying arc potential. Preferably, the first tab 160a, the second tab 160b, and the third tab 160c extend 0.5 mm to 2 mm outside the piezoelectric body 118, 120, including all ranges, sub-ranges, values, and endpoints of this range. In other words, at least one tab extends outside the piezoelectric body 118, 120 according to a distance greater than or equal to the thickness of each piezoelectric body. The piezoelectric stack 108 may include only the primary and auxiliary piezoelectrics 118, 120 and the foil 122, or may include one or more additional repeated sets of the primary and auxiliary piezoelectrics 118, 120 and the foil 122 on top of the first set of piezoelectrics.

[0095] Now refer to Fig.31 , the sliding bearing element 110 is assembled to and carried on the auxiliary piezoelectric body 120. The sliding bearing element 110 can be centrally located on the auxiliary piezoelectric body 120 and can be coupled to the auxiliary piezoelectric body 120 via epoxy or any other suitable adhesive, or coupled in any other manner suitable for use with a nanopositioner, especially in a cryogenic environment.

[0096] The bottom surface of the main piezoelectric 118 can be conductively coupled to the top surface 168 of the auxiliary piezoelectric 120. For example, although not shown, the wire can be coupled to the top surface 168 of the auxiliary piezoelectric 120 anywhere on the outside of the sliding bearing element 110, and coupled to the bottom surface of the main piezoelectric 118, for example, through the through hole 144 of the preload plate 104. The wire can be soldered, spot welded, or coupled to these piezoelectrics in any other suitable manner. In addition, any foil tab can be used as a positive electrode, and a positive lead or wire (not shown) can be coupled to the positive electrode, for example, via soldering, spot welding, or in any other suitable manner. Similarly, although not shown, a negative lead or wire can be coupled to the upper surface of the auxiliary electrode on the outside of the sliding bearing element 110, for example, via soldering or spot welding, or in any other suitable manner.

[0097] Now refer to Fig.32 , a piezoelectric stack 108 is schematically shown without a preload plate 104, the piezoelectric stack 108 comprising a main piezoelectric 118 and an auxiliary piezoelectric 120, a foil 122 is sandwiched between the main piezoelectric 118 and the auxiliary piezoelectric 120 and the sliding bearing element 110 is carried on the main piezoelectric 118 and the auxiliary piezoelectric 120. The configuration of the opposite orientation of the slope of the piezoelectric is shown. Moreover, the foil 122 is shown to extend beyond the side periphery of the piezoelectric.

[0098] Now refer to Fig.33 and Fig.34 , schematically shows a further simplified piezoelectric stack 114. Fig.33 , the negative lead is coupled to opposite facing sides of the primary piezoelectric 118 and the auxiliary piezoelectric 120, while the positive lead is coupled to the common facing sides of the primary piezoelectric 118 and the auxiliary piezoelectric 120 (e.g., via a common connection to the foil), and the piezoelectrics are shown in a quiescent state with no voltage applied. Fig.33 , a piezoelectric body is shown in an activated state when a voltage is applied.

[0099] As used herein, the terms "for example," "for example," "like," "such as," "including," "having," "comprising," and the like, when used in conjunction with a list of one or more elements, are to be interpreted as open-ended, meaning that the list does not exclude additional elements. Furthermore, as used herein, the term "may" is an expedient means of indicating only the optionality of, for example, the disclosed embodiments, elements, features, and the like, and should not be interpreted as obscuring any disclosure herein. Furthermore, directional terms such as front, rear, top, bottom, upper, lower, radial, circumferential, axial, lateral, longitudinal, vertical, horizontal, transverse, and / or the like are used as examples and are not necessarily limiting.

[0100] Finally, the subject matter of the present application is disclosed using various terms in conjunction with several clear illustrative embodiments and modifications to these embodiments. Unless used in a context requiring a different interpretation, all terms used herein are intended to be descriptive only, not necessarily restrictive, and should be described and interpreted according to their common and customary meanings in the art. And for convenience, each clear illustrative embodiment and modification is incorporated by reference into one or more other clear illustrative embodiments and modifications. Therefore, many other embodiments, modifications and their equivalents exist or have not yet been found, and therefore, it is neither intended nor possible to describe all such themes at present, and in view of this disclosure, a person of ordinary skill in the art will easily propose these themes. On the contrary, the present disclosure is intended to cover all such embodiments and modifications of the subject matter of the present application and its equivalents that fall within the broad scope of the appended claims.

Claims

1. A nanopositioner 10, comprising: A base 12, the base 12 comprising: The base plate 18 has: The base bottom 24 has: bottom surface 26, and The base top 28 has: Position driver mounting surface 30, and a pedestal bearing mounting surface 32 outboard of the position driver mounting surface 30, and an actuator eyelet 44 extending between the bottom surface and the position driver mounting surface, a position actuator 20 carried by the position actuator mounting surface 30 of the top portion 28 of the base plate 18 and including a set of drive electrodes 52, and a set of pedestal bearings 22 carried by the pedestal bearing mounting surface 32 of the top portion 28 of the pedestal plate 18; A carrier 14, which is movably supported relative to the base 12 and includes: A carrier plate 56 having: The carrier top 60 has: top surface 62, and The bottom portion 64 has: a position receiver mounting surface 66 corresponding to and facing the position driver mounting surface 30 of the top 28 of the base plate 18 of the base 12, and A carrier bearing mounting surface 68 is provided outboard of the position receiver mounting surface 66, a position receiver 57 carried by the position receiver mounting surface 66 of the bottom 64 of the carrier plate 56 and including a sense electrode 88 operatively coupled to the set of drive electrodes 52, and a set of carrier bearings 58 carried by the carrier bearing mounting surface 68 of the bottom 64 of the carrier plate 56 and operatively coupled to the set of pedestal bearings 22; and An actuator 16 operatively couples the carrier 14 to the base 12 and includes: a stator 98 removably coupled to the base 12 to facilitate removal and replacement of at least a portion of the stator 98, and an armature 100 operatively coupled to the stator 98 , extending through the actuator eyelet 44 of the base plate 18 of the base 12 , and coupled to the carrier 14 , The sense electrodes 88 and the set of drive electrodes 52 at least partially form a variable area capacitive position sensor.

2. The nanopositioner 10 according to claim 1, wherein: The base plate 18 also has a carrier bearing clearance surface 46 outboard of the location driver mounting surface 30. The base bearing mounting surface 32 of the top 28 of the base plate 18 of the base 12 is coplanar with the position driver mounting surface 30, The set of pedestal bearings 22 is carried on the outside of the set of drive electrodes 52. The carrier plate 56 also has a base bearing clearance surface 80 outside the position receiver surface 66, and The set of carrier bearings 58 are carried on the outside of the position receiver 57 .

3. The nanopositioner 10 according to claim 1, wherein: The base plate 18 also has a base end 34 having a base end surface 36 extending between the base bottom 24 and the base top 28, and a base 12 side having a base side surface 40 extending between the base bottom 24 and the base top 28 and between the base end 34, and The carrier plate 56 also has a carrier end 70 and a carrier side 74 , wherein the carrier end 70 has a carrier end surface 72 extending between the carrier bottom 64 and the carrier top 60 , and the carrier side 74 has a carrier side surface 76 extending between the carrier bottom 64 and the carrier top 60 and between the carrier end 70 . 4 . The nanopositioner 10 of claim 1 , wherein the position driver 20 includes a position drive plate 50 bridged over the actuator eyelet 44 of the base plate 18 of the base 12 . 5 . The nanopositioner 10 of claim 4 , further comprising a position driver support 54 that carries the position driver plate 50 and is directly coupled to the position driver mounting surface 30 .

6. The nanopositioner 10 of claim 1 wherein the set of base bearings 22 comprises V-groove rails, ball bearings carried between the V-groove rails, ball retaining spacers for retaining the ball bearings to the V-groove rails, and spacer creep stops, and wherein the set of carrier bearings 58 comprises V-groove rails mating with the ball bearings and the spacer creep stops.

7. The nanopositioner 10 of claim 1, wherein the carrier 14 further comprises a carrier bearing adjustment flange 82 at a side of the carrier plate 56, the carrier bearing adjustment flange 82 extending toward the base 12 and adjacent to the carrier bearing 58 at an inner side surface thereof. 8 . The nanopositioner 10 of claim 1 , wherein the position receiver 57 further comprises a guard electrode 90 having a portion surrounding the sensing electrode 88 . 9 . The nanopositioner 10 of claim 8 , wherein the guard electrode 90 has a central coaxial shield 92 , and the sense electrode 88 has a central coaxial conductor 94 extending through the central coaxial shield 92 .

10. A nanopositioner 10, comprising: A base 12, the base 12 comprising: a base plate 18 including an actuator eyelet 44 therethrough, a position driver 20, which is carried by the base plate 18 and includes a set of drive electrodes 52, and a set of pedestal bearings 22, the set of pedestal bearings 22 being carried by the pedestal plate 18; A carrier 14, which is movably supported relative to the base 12 and includes: Carrier plate 56, a position receiver 57 carried by the carrier plate 56 and comprising a sense electrode 88 operatively coupled to the set of drive electrodes 52, and a set of carrier bearings 58 carried by the carrier plate 56 and operatively coupled to the set of pedestal bearings 22; and An actuator 16 operatively couples the carrier 14 to the base 12 and includes: an armature 100 , the armature 100 being fixed relative to the carrier 14 ; and A stator 98 is removably coupled to the base 12 to facilitate removal and replacement of at least a portion of the stator 98 .

11. The nanopositioner 10 of claim 10, wherein the stator 98 of the actuator 16 comprises: A leaf spring 102 fastened to the base 12, A preload plate 104 positioned between the leaf spring 102 and the armature 100, A ball bearing pivot 106 carried by the leaf spring 102 and in contact with the preload plate 104, a shear piezoelectric stack 108 carried between the preload plate 104 and the armature 100, and A sliding bearing disk 110 is fixed to the shear piezoelectric stack 108 and is in sliding contact with the armature 100 .

12. A nanopositioner 10, comprising: A base 12, the base 12 comprising: a base plate 18 including an actuator eyelet 44 therethrough, a position driver 20, which is carried by the base plate 18 and includes a set of drive electrodes 52, and a set of pedestal bearings 22, the set of pedestal bearings 22 being carried by the pedestal plate 18; A carrier 14, which is movably supported relative to the base 12 and includes: Carrier plate 56, a position receiver 57 carried by the carrier plate 56 and comprising a sense electrode 88 operatively coupled to the set of drive electrodes 52, and a set of carrier bearings 58 carried by the carrier plate 56 and operatively coupled to the set of pedestal bearings 22; and An actuator 16 operatively couples the carrier 14 to the base 12 and includes: a stator 98 fixed relative to the base 12, and An armature 100 operatively coupled to the stator 98 extends through the actuator eyelet 44 of the base plate 18 of the base 12 and is coupled to the carrier 14 . 13 . The nanopositioner 10 of claim 12 , wherein the armature 100 of the actuator 16 is trapezoidal, including a platform 112 and legs 114 extending away from the platform 112 toward the carrier 14 and coupled to the carrier 14 . 14 . The nanopositioner 10 of claim 13 , wherein the legs 114 are pinned into the carrier 14 . 15 . The nanopositioner 10 of claim 13 , wherein the platform 112 carries a sliding bearing sheet 116 .

16. A nanopositioner 10, comprising: A base 12, the base 12 comprising: a base plate 18 including an actuator eyelet 44 therethrough, a position driver 20, which is carried by the base plate 18 and includes a set of drive electrodes 52, and a set of pedestal bearings 22, the set of pedestal bearings 22 being carried by the pedestal plate 18; A carrier 14, which is movably supported relative to the base 12 and includes: Carrier plate 56, a position receiver 57 carried by the carrier plate 56 and comprising a sense electrode 88 operatively coupled to the set of drive electrodes 52, and a set of carrier bearings 58 carried by the carrier plate 56 and operatively coupled to the set of pedestal bearings 22, The sense electrodes 88 and the set of drive electrodes 52 at least partially form a variable area capacitive position sensor.

17. The nanopositioner 10 of claim 16, wherein the set of drive electrodes 52 comprises corresponding triangular shaped elements.

18. The nanopositioner 10 of claim 17, wherein the corresponding triangular elements are interdigitated triangular elements.

19. The nanopositioner 10 of claim 18, wherein the interdigitated triangular elements include pennant-shaped elements forming a triangular space and triangular elements in the triangular space formed by the pennant-shaped elements.

20. A method of producing a nanopositioner 10, comprising: The top surface 162 and the bottom surface 26 of the base plate 18 are processed to be parallel to each other within the base plate tolerance; The top surface 78 and the bottom surface 82 of the carrier plate 56 are processed to be parallel to each other within the carrier plate tolerances; Mounting the actuator armature 100 to the bottom surface 82 of the carrier plate 56; Processing the bottom surface 170 of the platform 112 of the armature 100 to be parallel to the top surface 62 of the carrier plate 56 within the armature tolerance; removing the actuator armature 100 from the carrier plate 56; Mounting the position receiver 57 on the bottom surface 82 of the carrier plate 56; Mounting the position drive plate support 54 onto the top surface 162 of the base plate 18; Mounting the position driving plate 50 to the support 54 on the top surface 162 of the base plate 18; Measuring the parallelism of the position driving plate 50 to obtain a parallelism measurement value of the driving plate 50; as well as The parallelism measurement is used to process the top surface 172 of the drive plate support 54 so that the top surface 174 of the drive plate is parallel to the bottom surface 26 of the base plate 18 within drive plate tolerances.

21. The method of claim 20, wherein at least one of the tolerances of the base plate 18, carrier plate 56, or drive plate 50 is between 0 and 2 microns.

22. The method of claim 20, further comprising: mounting a plurality of sets of pedestal bearings 22 onto the top surface 162 of the pedestal plate 18 and mounting a plurality of sets of carrier bearings 58 onto the bottom surface 82 of the carrier plate 56; Assembling the carrier 14 including the carrier plate 56 and the plurality of carrier bearing sets 58 onto the base 12 including the base plate 18 and the plurality of base bearing sets 22; Mounting the actuator armature 100 to the bottom surface 82 of the carrier plate 56 through the actuator armature eyelet 44 in the base plate 18 and across the position drive plate 50; coupling a sliding bearing sheet 116 to the actuator armature 100; as well as An actuator stator 98 is mounted to the base plate 18 to capture the actuator armature 100 between the actuator stator 98 and the carrier plate 56 .

23. The method of claim 22, further comprising: The sets of carrier bearings 58 are arranged to engage with the sets of pillow block bearings 22 .

24. A method of repairing a nanopositioner 10 produced by the method of claim 22, comprising removing the actuator stator 98 from the base plate 18, replacing the piezoelectric stack 108 on the actuator stator 98 with a new piezoelectric stack 108 to produce a refurbished actuator stator 98, and reinstalling the refurbished actuator stator 98 onto the base plate 18. 25 . A method of repairing a nanopositioner 10 produced by the method of claim 22 , comprising removing the actuator stator 98 from the base plate 18 , replacing the actuator stator 98 with a new actuator stator 98 , and reinstalling the new actuator stator 98 onto the base plate 18 .

26. A piezoelectric stack 108, comprising: a main piezoelectric element 118 having main opposing faces 151 and main side portions 152 extending between the main opposing faces 151; an auxiliary piezoelectric element 120 having auxiliary opposing surfaces 168 and auxiliary side portions 170 extending between the auxiliary opposing surfaces 168; and A conductive foil 122, which is arranged between the facing surfaces of the main opposing surfaces 151 and the auxiliary opposing surfaces 168 of the main piezoelectric element 118 and the auxiliary piezoelectric element 120, and has at least one protrusion extending laterally outward relative to at least one of the main side portions 152 and at least one of the auxiliary side portions 170.

27. The piezoelectric stack of claim 26, wherein the at least one tab extends beyond the at least one major side 152 and the at least one auxiliary side 170 a distance greater than the thickness of each piezoelectric element.

28. The piezoelectric stack of claim 26, wherein the primary piezoelectric element 118 comprises a primary vertex 154 and a primary slope 155, wherein the primary vertex 154 extends between the primary opposing faces 151 and forms a primary corner between the primary side portions 152, wherein the primary slope 155 extends between the primary opposing faces 151 and is oriented in a first orientation, and wherein the auxiliary piezoelectric element 120 comprises an auxiliary vertex 172 and an auxiliary slope 174, wherein the auxiliary vertex 172 extends between the auxiliary opposing faces 168 and forms a secondary corner between the auxiliary side portions 170, wherein the auxiliary slope 174 extends between the auxiliary opposing faces 168 and is oriented in an auxiliary orientation opposite to the primary orientation to indicate the correct polarity of the piezoelectric element.

29. A piezoelectric actuator 16, comprising: The piezoelectric stack of claim 26; as well as A preload plate 104, the preload plate 104 comprising: Mounting surface, The piezoelectric surface 128 is arranged opposite to the mounting surface, A piezoelectric pocket 130 in the piezoelectric surface 128, the piezoelectric pocket 130 carrying the piezoelectric stack and at least partially defined by: The piezoelectric support surface 132 at the bottom of the piezoelectric pocket 130, a surrounding wall 134 extending away from the piezoelectric support surface 132, and The semicircular cutouts 138 at the corners of the piezoelectric pockets 130, The main side of the main piezoelectric element 118 and the auxiliary side of the auxiliary piezoelectric element 120 are laterally held by the surrounding wall 134. A foil pocket at least partially defined by at least a portion of the piezoelectric pocket 130 and at least one slot through at least one of the surrounding walls 134 of the piezoelectric pocket 130, wherein the at least one tab of the conductive foil 122 is carried in the at least one slot.

30. The piezoelectric actuator 16 of claim 29, wherein the preload plate 104 includes a beveled side, and wherein the at least one tab of the conductive foil 122 includes a slope corresponding to the beveled side of the preload plate 104 to assist in proper orientation of the conductive foil 122 relative to the preload plate 104.

31. The piezoelectric actuator 16 of claim 29, wherein the preload plate 104 further comprises a through hole 144 corresponding to the at least one tab of the conductive foil 122 to facilitate routing of a negative lead or wire therethrough.

32. The piezoelectric actuator 16 of claim 29, wherein the preload plate 104 further comprises a central through hole 146 extending between the mounting surface and the piezoelectric surface 128 and communicating with the mounting surface and the piezoelectric support surface 132. 33 . The piezoelectric actuator 16 of claim 32 , wherein the preload plate 104 further comprises a channel 148 in the piezoelectric support surface 132 and communicating with the central through hole 146 and extending from the central through hole 146 to a side surface of the preload plate 104 .

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