Transducer structure and method of adhering transducer to transducer structure

Abstract

The present application provides a transducer structure having at least one mechanical restraint. The at least one mechanical constraining device is shaped to receive the transducer such that the at least one mechanical constraining device at least partially constrains positioning of the transducer on the transducer structure. The at least one mechanical restraint secures at least a portion of the transducer in at least two degrees of freedom when the transducer is positioned on the transducer structure.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 336,521, filed on April 29, 2022, which is incorporated herein by reference in its entirety. Technical Field

[0003] The present invention relates to the field of transducers. More specifically, the present invention provides a transducer structure for receiving a transducer and a method of attaching a transducer to the transducer structure. Background Art

[0004] When the transducer is adhered to an object, the transducer can be used to measure a wide range of position data of the object. The transducer can measure one or more of temperature, force application, position, deformation and / or its derivatives. The accuracy of the transducer measurement depends on how the transducer is applied to the object. Typically, the transducer will be calibrated after the transducer is positioned on the object. Calibration adjustment is used to improve the accuracy of the measured data by compensating for errors introduced due to improper transducer placement and / or machining errors. Calibration may be time-consuming and expensive. Calibrating multiple objects and transducers may be even more time-consuming and expensive because the machining and position errors between each object may be different. As the number of degrees of freedom measured by the transducer increases, the difficulty associated with calibrating the transducer may increase.

[0005] Reference geometries, such as but not limited to fiducials and dowel pins, have been used to help accurately and repeatably place transducers. However, while these reference geometries may work well for larger scales, they may fail when dealing with smaller objects that require finely tuned measurements. Reference geometries also have their own positional and machining errors that may exacerbate errors in transducer readings, requiring additional calibration based on each specific transducer and object. Summary of the invention

[0006] According to one aspect of the present disclosure, there is provided a transducer structure, comprising:

[0007] at least one mechanical constraint shaped to receive the transducer such that the at least one mechanical constraint at least partially limits the positioning of the transducer on the transducer structure,

[0008] Wherein, when the transducer is positioned on the transducer structure, the at least one mechanical constraint fixes at least a portion of the transducer in at least two degrees of freedom.

[0009] In any embodiment, the at least one mechanical constraint may secure the transducer in at least three degrees of freedom.

[0010] In any embodiment, the at least one mechanical restraint may secure the transducer proximate a stress concentration region of the transducer structure.

[0011] In any embodiment, the at least one mechanical restraint may include an elongated member.

[0012] In any embodiment, the transducer may have a plurality of regions, and the at least one mechanical constraint may secure the transducer in at least two degrees of freedom across the plurality of regions.

[0013] In any embodiment, the at least one mechanical constraint may include constraining the transducer to at least one corner in a Cartesian plane and a rotational plane.

[0014] In any embodiment, the at least one mechanical restraint may include a groove having a plurality of walls extending from a base, and the groove has a groove height extending from the base to a top of each of the plurality of walls.

[0015] In any embodiment, the groove height may be greater than the thickness of the transducer.

[0016] In any embodiment, the groove height may vary.

[0017] In any embodiment, the at least one mechanical constraint may be positioned on the first surface, and the transducer may extend parallel to the first surface when the transducer is positioned on the transducer structure.

[0018] In any embodiment, the at least one mechanical constraint may secure the transducer in multiple degrees of freedom along the first surface when the transducer is positioned on the transducer structure.

[0019] In any embodiment, the at least one mechanical constraint may include a plurality of mechanical constraints, the transducer structure may include a plurality of surfaces, and wherein the plurality of mechanical constraints may secure the transducer in at least two degrees of freedom across each of the plurality of surfaces.

[0020] In any embodiment, the at least one mechanical restraint may have at least one channel for controlling displacement of the adhesive when the transducer is adhered to the transducer structure.

[0021] In any embodiment, the at least one channel may extend along multiple surfaces.

[0022] In any of the embodiments, the transducer structure may further include a strain controller for controlling the sensitivity of the transducer when the transducer is positioned on the transducer structure.

[0023] In any embodiment, the strain controller may be at least one cutout in the transducer structure forming an elongate member on which the transducer may be positioned.

[0024] In any embodiment, the transducer structure may be a monolithic structure.

[0025] In any embodiment, the at least one mechanical constraint may be matching shaped to receive the transducer, such that the shape of the at least one mechanical constraint may substantially constrain the positioning of the transducer on the transducer structure.

[0026] In any embodiment, the at least one mechanical constraint may surround at least a portion of a periphery of the transducer when the transducer is positioned on the transducer structure.

[0027] In any of the embodiments, the transducer may be flexible, such that the transducer can conform to curved surfaces.

[0028] In any of the embodiments, the transducer may be substantially incompressible and inextensible.

[0029] In any embodiment, the at least one mechanical restraint may be removable.

[0030] According to another aspect of the present disclosure, there is provided a method of adhering a transducer to a transducer structure having at least one mechanical constraint, the method comprising:

[0031] applying an adhesive to an area of ​​the transducer structure; and

[0032] A portion of the transducer is positioned in the region such that the at least one mechanical restraint secures at least a portion of the transducer in at least two degrees of freedom.

[0033] In any embodiment, the region may be a first region, and the portion may be a first portion, and the method may further include:

[0034] applying an adhesive to a second region of the transducer structure; and

[0035] A second portion of the transducer is positioned in the second region such that the at least one mechanical constraint secures at least a portion of the transducer from moving in at least two degrees of freedom.

[0036] In any embodiment, the method may further include:

[0037] applying adhesive to a third region of the transducer structure; and

[0038] A third portion of the transducer is positioned in the third region such that the at least one mechanical constraint secures at least a portion of the transducer in at least two degrees of freedom.

[0039] In any embodiment, the method may further include applying a clamping force to the portion of the transducer in the region.

[0040] In any embodiment, the at least one mechanical restraint device may include a plurality of mechanical restraint devices.

[0041] In any embodiment, the at least one mechanical restraint may be removable, and the method may further include removing the at least one mechanical restraint from the transducer structure.

[0042] In any embodiment, the at least one mechanical restraint may include an elongated member.

[0043] In any embodiment, the method may further include:

[0044] applying a clamping force to the portion of the transducer in the region; and

[0045] At least one strain controller is machined into the transducer structure.

[0046] In any of the embodiments, the clamping force may be applied until the adhesive is at least partially cured, and machining the at least one strain controller may occur after the adhesive is at least partially cured.

[0047] These and other aspects and features of various embodiments will be described in further detail below. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] For a better understanding of the described embodiments and to more clearly show how they may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which:

[0049] Figure 1 is a top perspective view of a transducer structure with a transducer positioned thereon;

[0050] Figure 2 yes Figure 1 A front perspective view of a transducer structure;

[0051] Figure 3 yes Figure 1 A bottom perspective view of a transducer structure;

[0052] Figure 4 yes Figure 1 A front perspective view of a transducer structure;

[0053] Figure 5A yes Figure 1A top perspective view of a transducer structure;

[0054] Figure 5B yes Figure 1 A top view of a transducer structure without a transducer;

[0055] Fig. 6A yes Figure 1 A side view of a transducer structure without a transducer;

[0056] Figure 6B yes Figure 1 A bottom view of a transducer structure without a transducer;

[0057] Fig. 7A yes Figure 1 A front perspective view of a transducer structure;

[0058] Figure 7B yes Figure 1 A front perspective view of a transducer structure;

[0059] Fig. 8A yes Figure 1 A top view of a transducer structure without a transducer;

[0060] Figure 8B yes Figure 1 A top view of a transducer structure without a transducer;

[0061] Fig.9A is along Figure 2 The line AA in Figure 1 A cross-sectional perspective view of a transducer structure;

[0062] Fig. 9B is along Figure 2 The line BB in Figure 1 A cross-sectional perspective view of a transducer structure;

[0063] Fig. 9C is along Figure 2 The line CC in Figure 1 A cross-sectional perspective view of a transducer structure;

[0064] Figures 10A-10D A progressive registration method for securing a transducer to a transducer structure is shown;

[0065] Figures 11A-11C Various spillover channels of the transducer structure are shown;

[0066] Fig.12 is a top perspective view of another transducer structure and a transducer;

[0067] Fig.13 yes Fig.12A top perspective view of a transducer structure;

[0068] Fig.14 yes Fig.12 A top perspective view of the transducer structure without the transducer.

[0069] Fig.15 yes Fig.12 A top view of a transducer structure;

[0070] Fig.16 yes Fig.12 A perspective view of a portion of a transducer structure;

[0071] Fig.17 is along Fig.15 The line DD in Fig.12 A cross-sectional perspective view of a transducer structure;

[0072] Fig.18 yes Fig.17 A top perspective view of a transducer structure;

[0073] Fig.19 yes Fig.17 A bottom perspective view of a transducer structure;

[0074] Fig. 20 is a flow chart of a method of adhering a transducer to a transducer structure;

[0075] Fig.21A , 21C and 21E are top views of the transducer structure at various stages of machining.

[0076] Fig.21B , 21D and 21F is along Fig.21A The line EE in Fig.21A A cross-sectional view of a transducer structure;

[0077] Fig.22A is a top view of another transducer structure;

[0078] Fig. 22B yes Fig.22A A cross-sectional view of a transducer structure;

[0079] Fig. 22C is a top view of another transducer structure;

[0080] Fig.22D yes Fig.22D A cross-sectional view of a transducer structure;

[0081] Fig.23A is a front perspective view of yet another transducer structure having an alignment mark for the transducer; and

[0082] Fig. 23B yes Fig.23A A front perspective view of the transducer structure after machining.

[0083] The drawings included herein are for illustrating various examples of articles, methods, and apparatuses of the teachings of the present specification and are not intended to limit the scope of the teachings in any way. DETAILED DESCRIPTION

[0084] Various devices, methods, and compositions are described below to provide examples of embodiments of each claimed invention. None of the embodiments described below limit any claimed invention, and any claimed invention may encompass devices and methods different from those described below. The claimed invention is not limited to devices, methods, and compositions having all the features of any one device, method, or composition described below, or features common to multiple or all devices, methods, or compositions described below. The device, method, or composition described below may not be an embodiment of any claimed invention. Any invention disclosed in the device, method, or composition described below that is not claimed in this document may be the subject of another protective instrument, such as a patent continuation application, and the applicant, inventor (and / or owner) has no intention of abandoning, not declaring protection, or disclosing such invention to the public by disclosing any such invention in this document.

[0085] The terms "an embodiment," "embodiments," "multiple embodiments," "the embodiment," "one or more embodiments," "some embodiments," and "an embodiment" mean "one or more (but not all) embodiments of the invention," unless expressly stated otherwise.

[0086] The terms "include," "comprising," and variations thereof all mean "including but not limited to," unless expressly stated otherwise. A listing of items does not imply that any or all of the items are mutually exclusive, unless expressly stated otherwise. The terms "a," "an," and "the" all mean "one or more," unless expressly stated otherwise.

[0087] As used herein and in the claims, two or more components are referred to as being "coupled," "connected," "attached," or "fastened" whenever there is a link, wherein the components are directly or indirectly (i.e., through one or more intermediate components) connected or operate together. As used herein and in the claims, two or more components are referred to as being "directly coupled," "directly connected," "directly attached," or "directly fastened" when the components are connected to each other in physical contact. All of the terms "coupled," "connected," "attached," and "fastened" do not distinguish the manner in which two or more components are connected together.

[0088] In addition, it will be appreciated that, for simplicity and clarity of description, reference numerals may be repeated in different figures to indicate corresponding or similar elements where deemed appropriate. In addition, many specific details are set forth in order to provide a thorough understanding of the example embodiments described herein. However, it will be appreciated by those of ordinary skill in the art that the example embodiments described herein may be implemented without these specific details. In other cases, well-known methods, processes, and components are not described in detail to avoid obscuring the example embodiments described herein. In addition, this specification should not be construed as limiting the scope of the example embodiments described herein.

[0089] As used herein, the term "and / or" is intended to mean an inclusive or. That is, "X and / or Y" is intended to mean X or Y or both. As a further example, "X, Y and / or Z" is intended to mean X or Y or Z or any combination thereof.

[0090] As used herein and in the claims, two elements are referred to as being "parallel" when they are parallel and spaced apart, or when the elements are co-linear.

[0091] General description of transducer structure

[0092] See also Figure 1 , which shows an exemplary embodiment of a transducer structure 100 having a transducer 300. The transducer 300 is positioned on the transducer structure 100 so that the transducer 300 can measure one or more types of data based on changes in the transducer structure 100. For example, the transducer 300 can include, but is not limited to, a force sensor, a strain gauge, a piezoelectric sensor, a capacitive force sensor, an optical force sensor, a fiber optic force sensor, a Bragg diffraction grating, a silicon strain gauge, a metal foil strain gauge, and / or combinations thereof.

[0093] In some embodiments, the transducer 300 may have a plurality of strain gauges (not shown). Each strain gauge may be positioned on the surface 110 to be measured. During use, when the transducer structure 100 is subjected to an applied force, the deformation of the transducer structure 100 causes the deformation of one or more surfaces 110 to be measured, thereby introducing strain into the surface 110 to be measured. Strain is the ratio of the measured length to the original length in a specific direction. The strain gauge is used to measure the relative change of the surface 110 to be measured, so that the deformation can be calculated. For example, if the surface 110 to be measured is compressed, the strain value will be less than 1. On the contrary, if the surface 110 to be measured is stretched, the strain value will be greater than 1.

[0094] Measuring the strain of the surface to be measured 110 caused by the application of force to the transducer structure 100 allows the user to calculate the value of the applied force that caused the deformation of the surface to be measured 110. This calculation can be determined by using the known material properties of the transducer structure 100 and the known geometry of the transducer structure 100. Therefore, by measuring the strain using a strain gauge, the applied force can be determined.

[0095] Strain is most easily measured along an axis, or in other words, within a particular degree of freedom (DoF). For example, strain can be measured along a first direction, a second direction, and a third direction, where the first, second, and third directions are each perpendicular to each other in a Cartesian coordinate system. These directions are often referred to as the x, y, and z directions. Figure 1 An example coordinate system 10 is shown. Each of the three directions has a translational component (movement in that direction) and a rotational component (rotation about the axis of that direction). The translational and rotational components produce six DoFs in a Cartesian coordinate system. Therefore, the applied force can have six components: Fx, Fy, Fz, Mx, My, and Mz, where F = force and M = moment.

[0096] The applied force may not be applied unidirectionally to the transducer structure 100. The force may be applied at an angle to the first, second and / or third direction of the structure 100, thereby applying a resultant force that can be divided into an axial force applied in each direction and a rotational force that causes a moment about each axis. Therefore, in order to measure the accurate applied force, the force along each axis can be calculated based on the measured strain value of each surface 110 to be measured.

[0097] The surface to be measured 110 may be an elongated member that is shaped to receive the transducer 300. For example, the surface to be measured 110 may be a thin beam. To measure force and / or torque, the transducer may be affixed to the elongated beam 112 to measure its relative deflection due to the net force / torque on the transducer structure 100. For example, the transducer 300 may have a plurality of strain gauge transducers and a plurality of elongated beams 112, wherein each of the one or more sensors is located on its corresponding elongated beam 112, such as Figure 1-10D as shown in .

[0098] The transducer 300 may include one or more temperature sensors. The inclusion of a temperature sensor may allow for local compensation of individual transducers. In other words, a temperature sensor may be used in conjunction with a deformation sensor to account for temperature variations and gradients, thereby improving the accuracy of the output data from the transducer 300.

[0099] See also Figure 1As shown, the transducer 300 can be a thin film transducer. As an example, the thickness of the transducer 300 can range from about 25 to about 150 microns. It is understood that the transducer 300 can have a thickness in the range of about 500 nanometers to about 500 microns.

[0100] The applied force may be from any application, for example, the transducer structure 100 is coupled to an end effector to interact with one or more objects that cause deformation to the transducer structure 100. For example, Figure 1 The transducer structure 100 shown in FIG. 1 is a finger that can be used to interact with an object and measure the force applied due to the interaction. As shown, the transducer structure 100 has a plurality of couplers 102 for attaching additional end effectors.

[0101] Limiting the positioning of the transducer on the transducer structure

[0102] The accuracy of positioning the transducer 300 on the transducer structure 100 at the desired position may have a great impact on the accuracy of the data measured by the transducer 100, especially when the transducer structure 100 is relatively small in scale. For small-scale applications, if the transducer 300 deviates by even a few millimeters, the measured data may be inaccurate and / or have low sensitivity, and may even reach the point where the data is unavailable. In order to solve the position error, the transducer 300 can be calibrated by various adjustments after the transducer 300 has been fixed to the transducer structure 100. However, such calibration may be very time-consuming and expensive, and cannot solve the problem of sensitivity loss. Although large-scale applications may still have increased errors due to improper placement of the transducer 300 on the surface 110 to be measured, due to the relative size of the surface 110 to be measured relative to the entire transducer structure 100, a deviation of a few millimeters will not usually form a corresponding error in the data. Having said that, the positioning of the transducer 300 on the surface 110 to be measured should be as accurate as possible in order to reduce or eliminate calibration costs after the transducer 300 has been fixed to the surface 110 to be measured.

[0103] According to one or more embodiments of the present invention, a transducer structure 100 having at least one mechanical constraint device 120 is provided, such as Figure 1. The at least one mechanical restraint 120 at least partially limits the positioning of the transducer 300 on the transducer structure 100. When the transducer 300 is positioned on the transducer structure 100, the at least one mechanical restraint 120 is also used to fix at least a portion of the transducer 200 in at least two DoFs. In other words, the at least one mechanical restraint 120 can mechanically hold the transducer 300 in place, thereby limiting the transducer 300 from moving in at least two DoFs. As used herein, fixing means substantially preventing movement. By fixing the transducer 300 in at least two DoFs using the at least one mechanical restraint 120, the transducer 300 is substantially prevented from moving in these two DoFs.

[0104] The design of the transducer structure 100 with at least one mechanical constraint 120 allows for improved and / or optimized accuracy when positioning the transducer 300 on the surface 110 to be measured. By optimizing the positional accuracy of the placement of the transducer 300, subsequent calibration adjustments can be minimized or eliminated. In other words, the use of the at least one mechanical constraint 120 to fix at least a portion of the transducer 300 in at least two DoFs acts as a form of calibration by design. An advantage of this design is that positional errors can be reduced or eliminated, thereby reducing or eliminating the need for post-application calibration adjustments, thereby saving time and money.

[0105] Furthermore, by designing the transducer structure 100 to constrain the positioning of the transducer 300, the design can be used to repeatedly manufacture multiple transducer structures 100 having nearly identical calibrations through design features. Thus, the positional accuracy of the transducer 300 on the transducer structure 100 can be repeatedly improved throughout the manufacturing process of multiple transducer structures 100, thereby reducing and / or eliminating the need for calibration adjustments.

[0106] It will be appreciated that errors such as machining errors and unexpected positional variations caused by clamping an object to a surface with an adhesive may result in minor positional inaccuracies in transducer 300. In such cases, calibration adjustments may be used to adjust for these errors.

[0107] A difficulty with measuring applied forces is that a force applied in a single direction may result in strain output measurements in multiple directions between different sensors. This phenomenon is known as crosstalk. For example, a strain gage intended to measure strain in the x-direction may be interfered with by an applied force in the y-direction, resulting in an error in the measurement of the x-direction strain gage, which has picked up strain from the applied force. Such an error may be caused, for example, by inaccurate application of the strain gage to the transducer structure 100 or by tolerance errors in machining. The transducer structure 100 may be designed so as to reduce the amount of crosstalk. For example, referring to Figure 1, the transducer structure 100 has a plurality of elongated beams 112 designed to facilitate transmission of force across the strain gauges in each of the x, y, and z directions to reduce the likelihood of crosstalk between two or more directions.

[0108] The at least one mechanical constraint 120 may be any mechanical feature that is used to limit the positioning of the transducer 300 on the transducer structure 100 and fix at least a portion of the transducer 300 in at least two degrees of freedom when the transducer 300 is positioned on the transducer structure 100. For example, the at least one mechanical constraint 120 may be (but is not limited to) an elongated member, a groove, a cavity, a mold, a solder paste surface tension adhesive lock.

[0109] The mechanical restraint device 120 may be a single mechanical restraint device, or may be a plurality of mechanical restraint devices. Figure 1 , the transducer structure 100 has a plurality of mechanical constraints 120. Each mechanical constraint 120 is operable to limit the positioning of the transducer 300 on the transducer structure 100 and to secure at least a portion of the transducer 300 in at least two DoFs when the transducer 300 is positioned on the structure.

[0110] The plurality of mechanical restraints 120 may be connected to each other, such as a groove, or may be separate from each other, such as a groove and an elongated member. Figure 1 As shown, the at least one mechanical constraint 120 is a plurality of mechanical constraints 120a, 120b, 120c, 120d, 120e. Each mechanical constraint 120 operates to limit the positioning of the transducer 300 on the transducer structure 100 and fix at least a portion of the transducer 300 in at least two DoFs. Therefore, the mechanical constraint 120 limits where the transducer 300 can be positioned on the structure 100, while also limiting the mobility of the transducer 300 after being positioned on the structure 100.

[0111] The at least one mechanical constraint 120 can limit the positioning of the transducer 300 on the transducer structure 100 so that the strain sensor is positioned within a certain error tolerance from a desired position. The desired position can vary depending on the desired application of the transducer structure 100. For example, in some embodiments, properly positioning the transducer 300 means positioning the strain sensor within 50 microns of the desired position. In some embodiments, the error tolerance may be in the range of (including but not limited to) about 1 micron to about 0.5 millimeters.

[0112] In some embodiments, the at least one mechanical restraint 120 may secure at least a portion of the transducer 300 in at least three DoFs. Figure 1As shown, the at least one mechanical constraint 120a is a groove on the surface of the transducer structure 100. The groove 120a has a plurality of walls 122 extending from a base 124, and has a groove height extending from the base 124 to the top of each of the plurality of walls 122. The groove 120a forms a key shape in the transducer structure 100, which receives the key portion 310 of the transducer 300. Therefore, the key portion 310 can be installed in the groove 120a on the transducer structure 100, so that the positioning of the transducer 300 is limited by the groove 120a. In addition, once located in the groove 120a, the key portion 310 of the transducer 300 is fixed by the groove 120a, thereby preventing the transducer 300 from moving in three DoFs. As shown, the key portion 310 of the transducer 300 is fixed in the translation x and y DoFs and the rotation z DoF. In other words, when the key portion 310 of the transducer 300 is located in the groove 120a of the transducer structure 100, the key portion 310 of the transducer 300 can neither translate in the xy plane nor rotate about the z axis. Thus, the transducer 300 is fixed in at least three DoFs.

[0113] The at least one mechanical restraint 120 may be shaped in any manner that limits the positioning of the transducer 300 and secures it in at least two DoFs. As described above, the recess 120a may be key-shaped for receiving the key portion 310 of the transducer 300. Figure 1 As illustrated, the mechanical constraint 120 can be a groove 120b forming a corner that fixes the transducer 300 in three DoFs. As shown, the groove 120b has a first portion 140 and a second portion 142 spaced apart from the first portion 140. The transducer 300 is correspondingly shaped so that the groove 120b can receive the transducer 300 between the first portion 140 and the second portion 142. As shown, the first portion 140 fixes the transducer 300 so that it cannot move in the negative x-direction and the negative y-direction, and the second portion 142 fixes the transducer 300 so that it cannot move in the positive x-direction and the positive y-direction. In addition, due to the separation of the first portion 140 and the second portion 142, the two portions prevent the transducer 300 from rotating about the z-axis. Therefore, the transducer 300 is fixed in three DoFs.

[0114] When the transducer 300 is positioned on the transducer structure 100, the at least one mechanical constraint 120 can protect the transducer 300 from damage by surrounding at least a portion of the periphery of the transducer 300. By surrounding at least a portion of the periphery of the transducer, the groove 120 can act as a buffer to protect the transducer 300 from damage. For example, the key-shaped portion of the groove 120 protects the key portion 310 of the transducer 300 from delamination and contact damage.

[0115] It will be appreciated that the groove height may be of any size, depending on the desired use of the transducer structure 100. For example, see Figure 1 , the mechanical constraint 120e near the front end of the transducer structure 100 is a groove 120e having a greater groove height than other mechanical constraints 120 on the transducer structure 100. This greater groove height can prevent the transducer structure 100 from contacting a surface and causing contact damage to the transducer 300 intentionally or unintentionally. In addition, the groove can prevent the transducer 300 from delaminating from the transducer structure 100.

[0116] like Figure 12-19 As illustrated, the at least one mechanical restraint 120 is an elongated member 120. The elongated member 120 has a generally triangular cross-sectional shape. Thus, the triangular elongated member 120 can be used to fix at least a portion of the transducer 300 in three degrees of freedom: translation in the xy plane and rotation about the z-axis. The transducer 300 has a hole 350 shaped to receive the elongated member 120. In other words, as Figure 12-19 , the hole 350 is generally triangular in shape. The mechanical restraint 120 is used to secure a portion of the transducer 300 in three DoFs while also limiting the positioning of the remainder of the transducer 300 along the transducer structure 100. The hole 350 may be any size and / or shape capable of receiving the elongated member 120 such that at least a portion of the transducer 300 is secured in at least two DoFs.

[0117] like Figure 12-19 As illustrated in FIG. 1 , the transducer structure 100 includes three elongated beams 112, each of which has two surfaces to be measured 110. The surfaces to be measured 110 are substantially perpendicular to each other along each elongated beam 112. Each surface to be measured 110 is used to receive the sensing portion 320 of the transducer 300. For example, Fig.16 As shown, each elongated beam 112 has a first surface to be measured 110a and a second surface to be measured 110b. Each surface to be measured 110a and 110b receives a corresponding sensing portion 320a and 320b of the transducer 300, respectively. Therefore, there are six sensing portions 320, which allows data to be measured on six DoFs (Fxyz and Mxyz).

[0118] In some embodiments, the at least one mechanical restraint device 120 may include a plurality of mechanical restraint devices 120 of different types, shapes, and / or sizes. Figure 1 As shown, the first mechanical constraint 120 is a key-shaped groove 120a for receiving the key portion 310 of the transducer 300, and the second mechanical constraint 120b is a groove forming a corner. In some embodiments, the transducer structure 100 may include a triangular elongated member 120 and a groove 120.

[0119] Response and transducer location

[0120] The proper positioning of the transducer 300 on the transducer structure 100 may vary depending on the purpose of the transducer structure. As previously mentioned, the transducer 300 may have at least one strain sensor. To improve the accuracy of strain measurement, the strain sensor may be positioned near stress concentration areas on the transducer structure. The size, shape, and / or number of stress concentration areas may be designed to maximize the dynamic range of the transducer 300 and / or minimize noise in the output signal. For example, Figure 1-10D As shown in FIG. 1 , the transducer structure 100 has three stress concentration areas 112. Each stress concentration area is an elongated beam 112 that forms a surface to be measured 110 for receiving a strain sensor. Thus, the at least one mechanical constraint 120 can fix at least a portion of the transducer 300 in at least two DoFs, so that each sensor in the transducer 300 is positioned near a corresponding stress concentration area on its corresponding elongated beam 112.

[0121] The at least one mechanical constraint 120 can be used to restrict the positioning of the transducer 300 so that the mechanical constraint 120 does not interfere with the surface to be measured 110. In other words, the fixation of the transducer 300 can occur at a position spaced apart from the surface to be measured 110, while restricting the positioning on the transducer 300 so that the strain sensor is properly positioned on the surface to be measured 110. For example, Figure 1 As shown in , the at least one mechanical constraint 120a is a groove that limits the positioning of the transducer 300 in three DoFs without extending onto the surface to be measured 110a located near the groove 120a. Therefore, the groove limits the positioning of the transducer 300 on the transducer structure 100, so that the strain sensor is optimally positioned on the slender beam 112a without damaging the structure of the slender beam 112a. An advantage of this design is that the separation of the at least one mechanical constraint 120 from the surface to be measured 110 reduces and / or prevents the generation of local stress points on the surface to be measured 110. Over time, local stress points may exacerbate errors through multiple cycles of loading of the surface to be measured. For example, if a screw is used to hold the transducer 300 in place, the screw will introduce a local stress point, which will interfere with the strain measurement of the slender beam 112 and may shorten the service life of the transducer structure 100.

[0122] In some embodiments, Figure 1-10DAs illustrated in FIG. 1 , the transducer structure 100 may be formed of a monolithic structure. In other words, the transducer structure 100 may be formed of a single piece of material that is machined and / or shaped to facilitate positioning of the transducer 300 on the transducer structure 100. By using a monolithic structure, the relative positions of the multiple transducers in the transducer 300 may be more easily maintained. An advantage of this design is that the sensitivity of each surface 110 to be measured on the transducer structure 100 may be more tightly controlled. For example, referring to FIG. Figure 1 , the transducer structure 100 is a unitary structure that is machined to receive the transducer 300. As previously described, the transducer structure 300 has three elongated beams 112. As shown, each of the elongated beams 112 is machined from the unitary structure.

[0123] In some embodiments, the structure 100 can be formed of multiple components that are fixed together to form a single structure. For example, multiple components can be, including but not limited to, bolted, laser welded, and / or epoxy-connected to form the structure 100.

[0124] The structure 100 may include one or more strain controllers 114 for controlling the sensitivity of the surface 110 to be measured on the structure 100. For example, each elongated beam 112 may be formed by a series of strain controllers 114 that change the sensitivity of the elongated beam 112. As illustrated, the strain controllers are cutouts 114 that are machined into the structure 100 to form the elongated beam 112. Using the cutouts 114 to control the sensitivity of the elongated beam 112 allows for an adjustable approach to sensitivity control, as the thickness of each cutout 114 can be varied during manufacturing depending on the desired sensitivity level of the transducer 300. The sensitivity is determined by the ratio of the cutout width to the elongated beam length. In addition, the strain controllers 114 can be used to control the overload condition of each beam 112. The use of the strain controllers 114 allows for converting thick beam portions of the monolithic structure into thin beams to increase the sensitivity of the structure 100. For example, the thin beams can be in a range including, but not limited to, about 300 microns to about 20 millimeters.

[0125] Thus, the transducer structure 100 can be used in applications with a wide range of sensitivities. By designing an adjustable scheme for sensitivity control, the transducer structure 100 can be used to pick up anything from food to steel, for example. Sensitivity control enables soft foods, such as vegetables or imitation crab, to be picked up by the same transducer structure 100 as the structure 100 used to pick up steel rods.

[0126] The one or more strain controllers 114 can be formed by any manufacturing method capable of precision cutting, including but not limited to wire EDM and / or laser water jet. In some embodiments, for example, when wire EDM is used, the strain controller 114 can be formed by drilling a starting hole 116 and forming the cut 114 using one or more manufacturing methods. The starting hole 116 can be in the range of about 0.7-1.0 mm, and the thickness of the cut 114 can be in the range of about 0.025 mm to about 0.5 mm. It is understood that the size and thickness can vary with the size of the transducer structure 100. Once the starting hole 116 is drilled, the cut 114 can be formed by, for example, wire EDM. For example, when the thickness of the cut 114 is in the range of about 150 microns, wire EDM can be used. In some embodiments, the starting hole 116 may not be required. For example, a laser water jet can be used without first forming the starting hole 116. For example, when the thickness of the cut 114 is in the range of less than 150 microns, a laser water jet can be used.

[0127] Complex Surface

[0128] In some embodiments, the transducer structure 100 can be designed to receive the transducer 300 at multiple regions 200, and the at least one mechanical constraint 120 can secure at least a portion of the transducer at at least two DoFs at the multiple regions 200. For example, the transducer 300 can have multiple strain sensors that allow a known relationship to be determined between the positioning of each strain sensor on the transducer structure 100. An advantage of this design is that a single transducer 300 can be used to measure strain in multiple locations across a complex surface. In addition, the known position of the sensing portion in the transducer 300 relative to each surface 110 to be measured can reduce calibration time and errors.

[0129] As described above, the transducer structure 100 may have three elongated beams 112, each of which is used to receive a strain sensor. Each elongated beam 112 includes a surface 110 to be measured. Figure 1As illustrated, the surface 110a to be measured extends between a first region 200a and a second region 200b. Each region 200 can be designed to receive a portion of the transducer 300 so that when the transducer 300 is located in the region 200, the portion of the transducer 300 is fixed in at least two DoFs in the region 200. Therefore, when all portions of the transducer 300 are located on the transducer structure 100, the at least one mechanical constraint 120 can be operated to fix at least a portion of the transducer 300 across each region 200 in the plurality of regions 200. In some embodiments, the at least one mechanical constraint 120 is a plurality of mechanical constraints 120 that fix the transducer 300 across each region 200 in the plurality of regions 200. It will be appreciated that the one or more mechanical constraints 120 can be used on a transducer 300 for measuring any number of DoFs. For example, the design can be used for three or four DoF robot wrists, generally three DoF joints, one to three DoF fingers, and / or structures with more than four DoF.

[0130] In some embodiments, region 200 may be located on a single surface. Figure 1 , the top surface 170 of the transducer structure 100 has a first region 200a (formed by the key portion of the groove 120a) and a second region 200b (formed by the corner 120b having the first portion 140 and the second portion 142). The two regions 200 operate to fix the first sensing portion 320a therebetween over three DoFs. In other words, the first sensing portion 320a is fixed in place on the first elongated beam 112a so that the transducer 300 extends parallel to the surface to be measured 110a when positioned on the transducer structure 100. Therefore, fixing the transducer 300 in the regions 200a and 200b results in the first sensing portion 320a being properly positioned on the surface to be measured 110a.

[0131] In some embodiments, region 200 may span multiple surfaces. Figure 1 , the transducer structure 300 has a plurality of surfaces for receiving transducers: a top surface 170, a side surface 172, and a front surface 174. Each of the plurality of surfaces has a surface to be measured 110. As shown, the transducer 300 extends parallel to each of the plurality of surfaces. In order to maintain the positioning of the transducer 300 across the plurality of surfaces on the transducer structure 100, there are a plurality of regions 200 across the surfaces, wherein each region is formed by one or more mechanical restraints 120. As described above, the top surface 170 has a first region 200a and a second region 200b. As shown in FIG. Figure 1-7BAs illustrated in FIG. 1 , the side surface 172 includes a third region 200c and a fourth region 200d, and the front surface 174 includes a fifth region 200e. The third region 200c is formed by the corner groove 120c, and the fourth region 200d is formed by the groove 120d. The fifth region 200e is formed by the groove 120e extending a considerable length of the front surface 174.

[0132] The second sensing portion 320b is fixed in place on the second surface to be measured 110b in three DoFs such that the transducer 300 extends parallel to the side surface 172 when located on the transducer structure 100. The third sensing portion 320c is fixed in place on the third surface to be measured 110c in three DoFs such that the transducer 300 extends parallel to the front surface 174 when located on the transducer structure 100. In other words, the fixing area 200 formed by the plurality of mechanical restraints 120 operates to fix the transducer 300 across the plurality of surfaces while positioning each strain sensor in an appropriate position on its corresponding surface to be measured. As previously described, Figure 1 The surface 110 to be measured illustrated in FIG. 1 is an elongated beam 112 .

[0133] Each mechanical restraint 120 in the plurality of mechanical restraints may be operable to keep the transducer 300 fixed in three DoFs. Figure 1 As shown in , each of the first, second and third sensing portions of the transducer 300 is fixed in translational x and y planes and rotationally fixed about the z axis. Thus, three DoFs are kept fixed on a complex surface structure with multiple surfaces.

[0134] The use of multiple mechanical restraints 120 may allow each portion of transducer 300 to be locally secured to transducer structure 100. Localized securing of transducer 300 may reduce the likelihood that transducer 300 will deform and / or collapse over a larger distance across transducer structure 100. In other words, transducer 300 may be secured at each region by each mechanical restraint 120, thereby facilitating placement of transducer 300 across an entire surface or multiple surfaces to be measured while minimizing or eliminating damage to transducer 300.

[0135] To facilitate the extension of transducer 300 across the multiple surfaces, transducer 300 may be made of a flexible material. Figure 1 , 5AAs shown in Figures 10A-10D, the transducer 300 is flexible so that it can be wrapped around one or more contoured surfaces. In other words, the transducer 300 can be bendable. The flexibility of the transducer 300 can allow the transducer 300 to be manufactured on a single plane while still allowing the transducer 300 to be wrapped around a complex transducer structure 100. Manufacturing the transducer 300 on a single plane can reduce manufacturing time, cost and / or error. In some embodiments, the transducer 300 can be substantially incompressible and inextensible. In some embodiments, a stretchable transducer 300 can be used so that the stretching of the transducer 300 is controllable.

[0136] The use of a flexible transducer 300 may allow for the manufacture of a transducer structure 100 having a complex surface. The shape of the transducer structure 100 may be customized according to the desired use of the transducer structure 100. For example, referring to Figure 1 , the transducer structure 100 has a plurality of mechanical restraints 120 extending along a plurality of surfaces. The plurality of surfaces include rounded edges that allow the transducer 300 to extend from one surface to the next while minimizing the possibility of damage to the transducer 300.

[0137] In addition, the use of a flexible transducer 300 can allow the transducer structure 100 to be manufactured at a variety of scales. For example, a large-scale application may have more dispersed stress concentrations, so the precise alignment of the transducer 300 with the stress concentration area may not be as important as in a smaller-scale application. In a smaller-scale application, it may be difficult to position the transducer 300 across multiple surfaces, and precise placement may be required to properly align the transducer 300 with the stress concentration area. The use of a flexible transducer 300 can increase the accuracy with which the transducer 300 can be positioned on the transducer structure 300 across complex surfaces while maintaining the desired position of the transducer 300 relative to the smaller stress concentration area. In other words, smaller-scale applications may inherently make multi-surface transducer applications more complex. Therefore, the flexible transducer 300 can reduce errors and improve the accuracy of the transducer structure 100.

[0138] As illustrated, the at least one mechanical constraint 120 may be cooperatively shaped to receive the transducer 300 such that the shape of the at least one mechanical constraint 120 limits the positioning of the transducer 300 on the transducer structure 100. Figure 1As shown in , the mating shape of the groove 120 extends across multiple surfaces, which enables the use of a single flexible transducer 300 to extend across multiple surfaces. The flexible transducer 300 may be able to adapt to curved surfaces. This flexibility reduces the possibility of delamination of the transducer 300 from the transducer structure 100 and can make it easier for the transducer 300 to adhere to the transducer structure 100. In addition, the use of curved surfaces can minimize the formation of local stress areas and can reduce the possibility of stress concentration in the transducer 300. Stress concentration in the transducer 300 may cause the transducer 300 to fail due to, including but not limited to, tension, bending, kinking, and / or tearing.

[0139] It will be appreciated that the corresponding mating shapes of the transducer 300 and the transducer structure 100 may be any shape and / or size that facilitates positioning the transducer 300 on the transducer structure 100. The mating shapes may be formed by a plurality of mechanical constraints 100, including but not limited to grooves and / or elongated members.

[0140] In some embodiments, the complex surface of the transducer structure 100 may include a single mechanical restraint 120 that operates to secure a portion of the transducer 300 in three DoFs. Figure 12-19 , the transducer structure has three elongated beams 112, forming six surfaces to be measured 110. Based on the positional constraints of the elongated members 120, the sensing portion of the transducer 300 is limited in how they are positioned on the transducer structure 100, thereby guiding the placement of the transducer 300 on the transducer structure 100. Therefore, the design of the transducer structure 100 can enable the transducer 300 to be positioned across a complex surface that includes three elongated beams 112 for sensing at six DoFs.

[0141] Bond line thickness control

[0142] The structure 100 may be designed to control the bond line thickness of the adhesive used to secure the transducer 300 to the transducer structure 100. The bond line thickness refers to the thickness or height of the adhesive on the surface of the transducer structure 100 that receives the adhesive and the transducer 300. Bond line thickness control may also be referred to as vertical registration because the bond line thickness controls the separation between the transducer structure 100 and the transducer 300, which in turn controls the relative distance between the top of the transducer 300 and the top of the transducer structure 100. The bond line thickness is an important feature to consider in the design of the transducer structure 100 because it directly affects the response and durability of the transducer 300 when placed on the transducer structure 100. For example, if the bond line thickness of the adhesive is too thin, there may not be a sufficient amount of adhesive to secure the transducer 300 to the transducer structure 100. If the bond line thickness of the adhesive is too thick, the adhesive may affect hysteresis and may cause transducer 300 to respond sluggishly because transducer 300 is too far from surface 110 to be measured.

[0143] In some embodiments, the at least one mechanical constraint 120 can be used to control the bond line thickness. For example, in embodiments where the mechanical constraint is a groove, the groove 120 can be used to control the amount of adhesive that can be received in the groove 120. Controlling the amount of adhesive that can be received in the groove can control the position of the transducer 100 perpendicular to the surface of the transducer structure 100. For example, the groove 120 can provide a desired thickness of the bond line so that when the transducer 300 is adhered to the transducer structure 100, the groove height allows the transducer 300 to be fixed in place with a specified amount of adhesive between the transducer structure 100 and the transducer 300. In other words, excess adhesive can be squeezed out of the groove 120 so that the bond line thickness is within an acceptable tolerance range of the desired range.

[0144] The at least one mechanical restraint 120 may be used to limit the positioning of the transducer 300 on the transducer structure 100, as previously described. For example, when an adhesive is applied to the transducer structure 100 and the transducer 300 is applied to the adhesive, the adhesive may cause the transducer 300 to slip or change position unexpectedly on the surface of the transducer structure 100. The mechanical restraint 120 (e.g., a groove) may reduce or eliminate position errors caused by adhesive slippage by preventing the transducer 300 from moving within the groove 120.

[0145] The one or more mechanical restraints 120 can prevent adhesive slippage or unintended positional changes of the transducer 300 on the various surfaces on the transducer structure 100. For example, when the transducer 300 is bent from one surface to another, the at least one mechanical restraint 120 can limit the positioning of the transducer 300 such that adhesive slippage on the various surfaces is minimized.

[0146] It will be appreciated that the bond line thickness may vary depending on the intended use of the transducer structure 100. For example, in some embodiments, the thickness of the adhesive is approximately 10 microns. The bond line thickness may vary depending on factors including, but not limited to, adhesive viscosity, surface roughness, and / or adhesive strength.

[0147] In some embodiments, the groove height may be constant across one or more surfaces of the transducer structure 100. For example, if a constant thickness value is desired for the bond line thickness, the groove height may be constant.

[0148] In some embodiments, the groove height can be variable on one or more surfaces. For example, if a thicker bond line thickness is required in one or more areas on the transducer structure 100, the groove thickness in that area can be increased. The groove height can be used to control the bond line thickness within a tolerance of, for example, about 10 microns to about 50 microns. The tolerance can vary depending on the use of the transducer structure 100. The groove height can be greater than the thickness of the transducer. The advantage of this design is that the groove can protect the transducer 300 from delamination or other damage.

[0149] In some embodiments, the transducer structure 100 may include at least one channel 180 for controlling the displacement of the adhesive when the transducer 300 is adhered to the transducer structure 100. Figure 1 and 8A 8B, the transducer structure 100 has an overflow channel 180 near the front surface 174 of the transducer structure 100. The overflow channel 180 is also near the cutout 114, which forms the elongated beam 112 near the front surface 174. The position of the overflow channel 180 relative to the cutout 114 can control the squeeze-out of the adhesive when the transducer 300 is clamped to the transducer structure 100. In other words, when the transducer 300 is clamped to the front surface 174, some adhesive may be squeezed out of the groove 120. If the adhesive overflows into the cutout 114 forming the elongated beam 112c, the elongated beam 112c will no longer work as a thin beam because it will be adhered to the rest of the monolithic structure of the transducer structure 100. Therefore, overflowing the adhesive into the cutout 114 due to squeeze-out may cause inaccurate measurements. For example, even a drop of adhesive overflowing into the cutout 114 may greatly affect the accuracy of the transducer measurement.

[0150] It will be appreciated that the at least one channel 180 may extend across one surface or across multiple surfaces. In some embodiments, there may be multiple channels 180 on and / or in the transducer structure 100 .

[0151] In some embodiments, the overflow channel may extend completely through the transducer structure 100, such as Figure 1 One or more overflow channels may not extend through the entire transducer structure 100 and may alternatively or additionally form a notch 182 for receiving excess adhesive, such as Figures 11A-11C exemplified. Fig. 11B (i) shows a severe failure case when adhesive 20 enters cutout 114 . Fig. 11B (ii) shows a severe failure case when the adhesive used is insufficient to secure the transducer 300 to the transducer structure 100 . Fig. 11B (iii) shows the use of an overflow channel 180, which is a notch for receiving excess adhesive 20. The one or more overflow channels 180 can be any size and / or shape that is convenient for accommodating excess adhesive 20. Fig. 11C As illustrated, channel 180 may be a series of notches for receiving adhesive 20 .

[0152] Thus, designing the transducer structure 100 to control the bond line thickness may provide one or more advantages including, but not limited to, controlling the amount of adhesive used, controlling squeeze-out during clamping, and / or preventing manufacturing defects by preventing adhesive from flowing to undesirable locations on the transducer structure 100, as the transducer structure 100 may be compromised by excess adhesive.

[0153] It is understood that the adhesive can be any material capable of fixing the transducer 300 to the transducer structure 100. For example, the adhesive can be, but is not limited to, a semi-solid, liquid, pressure sensitive adhesive, epoxy, cyanoacrylate, acrylic, polyurethane, silica, and / or combinations thereof. The adhesive can be a composite material loaded with, but is not limited to, silica, glass, carbide, and / or combinations thereof. In some embodiments, the adhesive can be elastically toughened. The adhesive can form an adhesive bond by, but is not limited to, light, moisture, and / or heat curing. In some embodiments, the adhesive can use both heat curing and two-part curing epoxies and cyanoacrylates.

[0154] In some embodiments, multiple adhesives may be used on the transducer structure 300. The adhesive may differ between different regions or components of the transducer structure 100. For example, a first adhesive may be used to secure portions of the transducer 300 to the elongated beam 112, and a second adhesive may be used to secure the remainder of the transducer 300 to the transducer structure. The first adhesive and the second adhesive may be any adhesive or combination of adhesives. Using different adhesives for different components of the transducer 300 may increase the speed and repeatability of the manufacturing process, and may improve the manufacture of more complex and longer form factors of the transducer 300.

[0155] Temporary mechanical restraint

[0156] In some embodiments, the at least one mechanical restraint 120 may be temporarily positioned on the transducer structure 100. In other words, the at least one mechanical restraint 120 may be removable from the structure 100. For example, the at least one mechanical restraint 120 may be an elongated member received in a slot of the transducer structure 100. The elongated member may be used to at least partially constrain the positioning of the transducer 300 on the transducer structure 100 and may secure at least a portion of the transducer 300 in at least two DoFs while the transducer 300 is positioned on the transducer structure 100. Once the adhesive used to secure the transducer 300 to the transducer structure 100 has at least partially cured, the elongated member may be removed from the slot on the transducer structure 100.

[0157] As another example, the at least one mechanical restraint 120 can be a template that is positioned to contact the transducer structure 100 and can be held in place while the transducer 300 is adhered to the structure 100. The template can be used to constrain the positioning of the transducer 300 on the transducer structure 100 and can operate to secure at least a portion of the transducer 300 in at least two DoFs. Once the adhesive has cured or mostly cured, the template can be removed from the transducer structure 100. The template can also be used as an extrusion control method.

[0158] In some embodiments, there may be a plurality of mechanical restraints 120 , wherein at least one mechanical restraint 120 forms a permanent component of structure 100 , and wherein at least one mechanical restraint 120 is removable from structure 100 .

[0159] Progressive Registration Method

[0160] The method of securing the transducer 300 to the transducer structure 100 may occur in the form of progressive registration. In other words, a first portion of the transducer may be secured, and then a next portion of the transducer may be secured. In this manner, the positioning of the transducer 300 on the transducer structure 100 may be optimized, as previously described, by securing portions of the transducer in place using one or more mechanical restraints 120 prior to securing the remainder of the transducer to ensure proper positioning.

[0161] See also Fig. 20, which shows a flow chart of an exemplary method 1000 of adhering a transducer 300 to a transducer structure 100 having at least one mechanical restraint 120. At 1100, an adhesive is applied to a first region 190 of the transducer structure. At 1110, a portion of the transducer 300 is positioned in the first region 190 such that the at least one mechanical restraint 120 secures at least a portion of the transducer in at least two DoFs, as shown. Fig. 10B exemplified in .

[0162] Optionally, at 1200, an adhesive is applied to the second region 192 of the transducer structure 100. At 1210, a portion of the transducer 300 is positioned in the second region 192 such that the at least one mechanical restraint 120 secures at least a portion of the transducer to prevent movement in at least two DoFs, such as Fig. 10C exemplified in .

[0163] Optionally, at 1300, an adhesive is applied to the third region 194 of the transducer structure 100. At 1310, a portion of the transducer 300 is positioned in the third region 194 such that the at least one mechanical restraint 120 secures at least a portion of the transducer to prevent movement in at least two DoFs, such as Fig. 10D exemplified in .

[0164] It will be appreciated that the number of steps of method 1000 will vary depending on the design of transducer structure 100 and its complexity. The number of mechanical restraints 120 may vary. For example, there may be a different mechanical restraint 120 for each of 1100, 1200, 1300. Alternatively, a single mechanical restraint 120 may be used on multiple areas. Mechanical restraint 120 may be removable, and method 1000 may include removing mechanical restraint 120 from structure 100 after the adhesive has cured or substantially cured.

[0165] In some embodiments, the method 1000 may include applying a clamping force to one or more portions of the transducer 300 in one or more regions. The clamping force may be used to apply pressure to the transducer 300 while the adhesive is curing on the transducer structure 100. The clamping force may vary depending on the adhesive material used. In some embodiments, the adhesive may not require a clamping force to cure properly. For example, an adhesive with a lower viscosity (e.g., epoxy) may require less clamping force or no clamping force.

[0166] In some embodiments, method 1000 may include using multiple adhesives. For example, a first adhesive (e.g., epoxy) may be used to secure transducer 300 to transducer structure 100 across elongated member 112, and a second adhesive (e.g., pressure sensitive adhesive) may be used to adhere the remainder of transducer 300 to transducer structure 100. It is understood that the multiple adhesives may be any adhesive or combination of adhesives. An advantage of this design is that the manufacturing process may be faster and more repeatable.

[0167] Manufacturing method

[0168] The methods of manufacturing the transducer structure 100 and securing the transducer 300 to the transducer structure 100 may vary depending on the design of the transducer structure 100. For example, in some embodiments, the transducer structure 100 may be machined with one or more strain controllers 114, otherwise referred to as cutouts 114. The cutouts 114 may be used to create one or more elongated beams 112, as previously described. One or more mechanical restraints 120 may be machined into one or more surfaces on the transducer structure 100. Once the transducer structure 100 is fully machined, the transducer 300 may be adhered to the transducer structure 100, as previously described.

[0169] In this embodiment, care must be taken when clamping the transducer 300 to the transducer structure 100 to prevent damage to the surface to be measured 110. The surface to be measured 110 is typically very thin and may be damaged by the clamping force used to secure the transducer 300 to the transducer structure 100. When clamping occurs at higher temperatures, the heat may exacerbate the damage. The amount of damage caused by the clamping force may depend on the size and strength of the structure 100 and / or the elongated beam 112. For example, a smaller and / or thinner beam 112 may be more easily damaged by clamping than a larger and / or thicker beam 112. To prevent damage to the elongated beam 112, a shim may be placed in the cutout 114 to prevent the beam 112 from warping and / or plastic deformation.

[0170] The sensors in the transducer 300 may be registered to the transducer 300. Therefore, if position errors are introduced in the position of the sensors relative to the surface 110 to be measured, additional calibration may be required to compensate for these errors.

[0171] In some embodiments, the transducer 300 may be secured to the transducer structure 100 prior to machining the cutouts 114 into the transducer structure 100. Once the transducer 300 has been secured to the transducer structure 100, the cutouts 114 may be machined into the structure 100 to form one or more elongated beams 112. An advantage of this approach is that the transducer 300 may be securely secured to the transducer structure 100 prior to machining fragile components such as the elongated beams 112 into the structure 100. In other words, the transducer 300 may be clamped, for example, to a surface of the transducer structure 100 while minimizing or eliminating damage to the structure 100. Once the transducer 300 is securely secured, more fragile components such as the elongated beams 112 may be machined into the transducer structure 100.

[0172] Once the transducer 300 has been secured to the transducer structure 100, and the surface to be measured 110 has been machined into the structure 100, the actual position of the transducer 300 may be used to register the position of the transducer 300. This process has the advantage that the position of the transducer 300 may be registered more accurately.

[0173] In some embodiments, the transducer structure 100 may be machined using a conductive machining process. For example, as previously described, the cutout 114 may be formed using a wire EDM. The conductive machining process cuts conductive material while leaving non-conductive material completely or barely touched. Thus, when the transducer 300 is secured to the transducer structure 100 prior to machining the cutout 114, the cutout 114 may be cut using a wire EDM while minimizing or eliminating damage to the transducer 300. Using a conductive machining process on a conductive surface of the transducer structure 100 with a non-conductive transducer 300 may allow very fine machining while avoiding damage to the transducer 300. The transducer 300 may be made of a material that can withstand autoclaving, further reducing damage from machining.

[0174] In some embodiments, the transducer 300 may include at least a portion made of a conductive material. For example, the transducer 300 may include copper traces that may guide a conductive machining process. Thus, a conductive machining process used to machine the surface 110 to be measured may also be used to cut the transducer 300. The conductive components of the transducer 300 may be positioned in such a way as to avoid damaging sensitive components of the transducer 300, such as a sensor.

[0175] In some embodiments, alignment marks may be used to improve the tolerance of placing the transducer 300 on the transducer structure 100. For example, in embodiments where the transducer 300 is applied to the transducer structure 100 prior to machining the surface 100 to be measured, the alignment marks on the transducer 300 may guide where the cutout 114 should be machined so that the transducer 300 is registered to the proper location on the transducer structure 100.

[0176] As previously mentioned, when machining the cutout 114 prior to securing the transducer 300, care should be taken to avoid the adhesive from contacting the cutout 114. Fig.22A and 22B , when the cutout 114 is machined before the transducer 300 is positioned on the transducer structure 300, the edge of the transducer 300 can be positioned at a distance from the cutout 114. As shown, the squeeze-out from the adhesive 20 extends beyond the edge of the transducer 300. Therefore, the space between the cutout 114 and the transducer 300 can be designed to reduce the possibility of the adhesive 20 entering the cutout 114. Even just one drop of adhesive in the cutout 114 may significantly affect the performance of the transducer 300. Alternatively, the cutout 114 can be machined after the transducer 300 has been adhered to the transducer structure 300. Therefore, by machining the cutout 114 after the transducer 300 has been adhered to the transducer structure 100, the problem of extrusion damaging the cutout 114 can be avoided.

[0177] In other words, when adhering the transducer 300 to the transducer structure 100, a clamping force may be applied to the portion of the transducer 300 on the transducer structure 100 to provide pressure to the adhesive 20. The clamping force may be applied until the adhesive 20 cures. Once the adhesive 20 cures, the strain controller 114 may be machined into the structure 100. It will be appreciated that the degree of cure prior to the machining process may vary depending on the adhesive used.

[0178] When the transducer 300 is applied to the transducer structure 100 after the cutout 114 has been machined, the relative position of the sensor on the transducer 300 with respect to the surface to be measured 110 may be slightly offset, for example, due to the position errors described above. In addition, the pressure used to apply the transducer 300 to the structure 100 may damage sensitive components, such as the surface to be measured 110. Therefore, by fixing the transducer 300 to the transducer structure 100 before machining the cutout 114, and by using conductive machining methods, the cutout 114 can be formed while minimizing or eliminating damage to the transducer structure 100, damage caused by clamping can be minimized or eliminated, alignment marks, such as on the transducer 300, can be used to improve tolerances, and / or calibration requirements can be further reduced and / or eliminated.

[0179] like Figures 21A-21F As illustrated in FIG. 1 , transducer 300 has alignment marks 360. Alignment marks 360 can be used to identify where the sensor is located in transducer 300 and / or where the surface to be measured should be located in structure 100 so that the cutout 114 can be machined in the desired location. In some embodiments, transducer 300 can have multiple alignment marks 360. Alignment marks 360 can be used to provide a visual indication of any type of machining or positioning process associated with transducer 300 and / or transducer structure 100.

[0180] Once the transducer 300 is fixed to the surface of the transducer structure 100 ( Fig. 21C and 21D ), a machining method such as wire cutting EDM can be used to cut the alignment mark 360 ( Fig.21E and 21F ). By indicating the desired cutting position of the cutout 114 relative to the transducer 300, positional errors can be reduced. Another advantage of this design is that errors can be repeatedly reduced across multiple transducer structures 100.

[0181] In some embodiments, transducer 300 may have one or more additional portions that include alignment marks 360. These additional portions may be used to overlap certain areas on transducer structure 100 to provide a visual indication of where to machine structure 100. In other words, transducer 300 may be designed to include portions that specifically guide the machining of transducer structure 100. For example, Fig.23A As shown in FIG. 1 , the transducer 300 has an alignment mark 360 that overlaps a top portion of the transducer structure 100. The transducer 300 is located on the side of the structure 100 with an overlapping portion extending to the top surface. Fig. 23B As illustrated in FIG. 3 , the alignment mark 360 has been machined to form the surface 110 to be measured.

[0182] It is understood that alignment mark 360 may be partially or fully cut during the machining process. For example, in some embodiments, alignment mark 360 may indicate where cutout 114 should be located, and cutout 114 may extend only partially along the length of alignment mark 360.

[0183] In some embodiments, alignment marks 360 may be used to provide a visual indication of possible misalignment. Fig. 22C and 22D , an error is introduced during the machining of the cutout 114. This error is indicated by the misalignment of the alignment mark 360 from the cutout 114, whereby the alignment mark 360 is only partially cut. The error may be caused by, for example, machining errors, transducer manufacturing errors, laser misalignment, and / or photomask misalignment. This visual indication of misalignment may be used to assist the user in calibration, or may indicate that the structure 100 may need to be replaced.

[0184] Although the above content describes the features of the example embodiments, it is understood that some features and / or functions of the described embodiments are susceptible to modification without departing from the spirit and operating principles of the described embodiments. For example, the various features described by the given embodiments or examples may be selectively combined with each other. Therefore, the above description is intended to illustrate the claimed concept and is non-restrictive. It will be appreciated by those skilled in the art that other variations and modifications may be made without departing from the scope of the invention as defined in the appended claims. The scope of the claims should not be limited by the preferred embodiments and examples, but should be given the broadest interpretation consistent with the specification as a whole.

Claims

1. A transducer structure, comprising: at least one mechanical constraint shaped to receive a transducer such that the at least one mechanical constraint at least partially limits the positioning of the transducer on the transducer structure, Wherein, when the transducer is positioned on the transducer structure, the at least one mechanical constraint fixes at least a portion of the transducer in at least two degrees of freedom.

2. The transducer structure of claim 1, wherein the at least one mechanical constraint secures the transducer in at least three degrees of freedom.

3. The transducer structure of claim 1, wherein the at least one mechanical restraint secures the transducer near a stress concentration region of the transducer structure.

4. The transducer structure of claim 1, wherein the at least one mechanical constraint comprises an elongated member.

5. The transducer structure of claim 1, wherein the transducer has a plurality of regions and the at least one mechanical constraint secures the transducer in at least two degrees of freedom across the plurality of regions.

6. The transducer structure of claim 1, wherein the at least one mechanical constraint comprises at least one corner, the at least one corner constraining the transducer in a Cartesian plane and a rotational plane.

7. The transducer structure of claim 1, wherein the at least one mechanical constraint comprises a groove having a plurality of walls extending from a base, and the groove has a groove height extending from the base to a top of each of the plurality of walls. The transducer structure according to claim 7 , wherein the groove height is greater than the thickness of the transducer.

9. The transducer structure of claim 8, wherein the groove height is variable.

10. The transducer structure of claim 1, wherein the at least one mechanical constraint is positioned on a first surface, and the transducer extends parallel to the first surface when the transducer is positioned on the transducer structure.

11. The transducer structure of claim 10, wherein the at least one mechanical constraint secures the transducer in multiple degrees of freedom along the first surface when the transducer is positioned on the transducer structure.

12. The transducer structure of claim 1, wherein the at least one mechanical constraint comprises a plurality of mechanical constraints, the transducer structure comprises a plurality of surfaces, and wherein the plurality of mechanical constraints secure the transducer in at least two degrees of freedom across each of the plurality of surfaces.

13. The transducer structure of claim 1, wherein the at least one mechanical constraint has at least one channel for controlling displacement of an adhesive when the transducer is adhered to the transducer structure.

14. The transducer structure of claim 13, wherein the at least one channel extends along a plurality of surfaces.

15. The transducer structure of claim 1, further comprising a strain controller for controlling the sensitivity of the transducer when the transducer is positioned on the transducer structure.

16. The transducer of claim 15, wherein the strain controller is at least one cutout in the transducer structure, the at least one cutout forming an elongate member on which the transducer is positionable.

17. The transducer structure of claim 1, wherein the transducer structure is a monolithic structure.

18. The transducer structure of claim 1, wherein the at least one mechanical constraint is shape matched to receive the transducer such that a shape of the at least one mechanical constraint substantially limits positioning of the transducer on the transducer structure.

19. The transducer structure of claim 1, wherein the at least one mechanical constraint surrounds at least a portion of a periphery of the transducer when the transducer is positioned on the transducer structure.

20. The transducer structure of claim 1, wherein the transducer is flexible such that the transducer can conform to a curved surface.

21. The transducer structure of claim 20, wherein the transducer is substantially incompressible and inextensible.

22. The transducer structure of claim 1, wherein the at least one mechanical restraint is removable.

23. A method of adhering a transducer to a transducer structure having at least one mechanical restraint, the method comprising: applying an adhesive to an area of ​​the transducer structure; as well as A portion of the transducer is positioned in the region such that the at least one mechanical constraint secures at least a portion of the transducer in at least two degrees of freedom.

24. The method of claim 23, wherein the region is a first region and the portion is a first portion, the method further comprising: applying the adhesive to a second area of ​​the transducer structure; as well as A second portion of the transducer is positioned in the second region such that the at least one mechanical constraint secures at least a portion of the transducer from moving in at least two degrees of freedom.

25. The method according to claim 24, further comprising: applying the adhesive to a third region of the transducer structure; as well as A third portion of the transducer is positioned in the third region such that the at least one mechanical constraint secures at least a portion of the transducer in at least two degrees of freedom.

26. The method of claim 23, further comprising applying a clamping force to the portion of the transducer in the region.

27. The method of claim 23, wherein the at least one mechanical restraint device comprises a plurality of mechanical restraint devices.

28. The method of claim 23, wherein the at least one mechanical restraint is removable, and the method further comprises removing the at least one mechanical restraint from the transducer structure.

29. The method of claim 23, wherein the at least one mechanical restraint comprises an elongated member.

30. The method of claim 23, further comprising: applying a clamping force to the portion of the transducer in the region; as well as At least one strain controller is machined into the transducer structure.

31. The method of claim 30, wherein the clamping force is applied until the adhesive is at least partially cured, and the at least one strain controller is machined after the adhesive is at least partially cured.

Images