Transducer structure and method for bonding a transducer to a transducer structure - Patents.com

Abstract

A transducer structure is provided having at least one mechanical limiting feature configured to receive a transducer such that the at least one mechanical limiting feature at least partially limits placement of the transducer relative to the transducer structure, the at least one mechanical limiting feature fixing at least a portion of the transducer in at least two degrees of freedom when the transducer is placed on the transducer structure.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 63 / 336,521, filed April 29, 2022, which is incorporated by reference in its entirety.

[0002] The present invention is directed to the field of transducers. More particularly, the present invention provides a transducer structure for receiving a transducer and a method for adhering a transducer to a transducer structure. [Background technology]

[0003] When attached to a body, the transducer can be used to measure a wide range of positional data of the body. The transducer can measure one or more of temperature, force application, position, deformation, and / or derivatives thereof. The accuracy of the transducer measurement depends on how the transducer is applied to the body. Often, the transducer is calibrated after being positioned on the body. Calibration adjustments are used to improve the accuracy of the measured data by compensating for errors derived from improper placement and / or machining errors of the transducer. Calibration can be time consuming and expensive. Calibrating multiple bodies and transducers can be even more time consuming and expensive, as machining and positional errors can vary between each body. Difficulties associated with calibrating transducers can be exacerbated as the number of degrees of freedom measured by the transducer increases.

[0004] Reference geometries, such as, but not limited to, fiducials and locating pins, are used to facilitate accurate and repeatable placement of transducers. However, while these reference geometries are applicable at large dimensions, they can break down when dealing with small bodies that require precisely tuned measurements. The reference geometries also have their own positional and machining errors that can exacerbate errors in the transducer readings, necessitating further calibration based on each particular transducer and body. Summary of the Invention [Means for solving the problem]

[0005] According to one aspect of the present disclosure, there is provided a transducer structure, the transducer structure comprising: at least one mechanical limiting portion configured to receive the transducer such that the at least one mechanical limiting portion at least partially limits placement of the transducer relative to the transducer structure; The at least one mechanical limiter fixes at least a portion of the transducer in at least two degrees of freedom when the transducer is disposed on the transducer structure.

[0006] In any embodiment, at least one mechanical limiter can fix the transducer in at least three degrees of freedom.

[0007] In any embodiment, at least one mechanical restraint can secure the transducer near a stress concentration zone of the transducer structure.

[0008] In any embodiment, the at least one mechanical restriction can include an elongate member.

[0009] In any embodiment, the transducer can have multiple zones and at least one mechanical limiter can fix the transducer in at least two degrees of freedom across the multiple zones.

[0010] In any embodiment, the at least one mechanical limit can include at least one corner that limits the transducer in a Cartesian plane and in a plane of rotation.

[0011] In any embodiment, the at least one mechanical restriction can include a groove having a plurality of walls extending from a base, the groove having a groove height extending from the base to a top of each of the plurality of walls.

[0012] In any embodiment, the groove height can be greater than the thickness of the transducer.

[0013] In any embodiment, the groove height may be variable.

[0014] In any embodiment, the at least one mechanical limiter can be disposed on the first surface and the transducer can extend parallel to the first surface when disposed on the transducer structure.

[0015] In any embodiment, the at least one mechanical limiter can fix the transducer in multiple degrees of freedom along the first surface when the transducer is placed on the transducer structure.

[0016] In any embodiment, the at least one mechanical limiter can include multiple mechanical limits, and the transducer structure can include multiple surfaces, and the multiple mechanical limits can fix the transducer in at least two degrees of freedom across each surface in the multiple surfaces.

[0017] In any embodiment, the at least one mechanical limiter can have at least one channel for controlling the displacement of the adhesive when the transducer is bonded to the transducer structure.

[0018] In any embodiment, at least one channel can extend along multiple surfaces.

[0019] In any embodiment, the transducer structure may further comprise a distortion controller for controlling the sensitivity of the transducer when the transducer is disposed on the transducer structure.

[0020] In any embodiment, the strain controller may be at least one kerf in the transducer structure that forms an elongated member in which the transducer can be positioned.

[0021] In any embodiment, the transducer structure may be an integrated structure.

[0022] In any embodiment, the at least one mechanical limiting portion may be matingly shaped to receive the transducer such that a shape of the at least one mechanical limiting portion substantially limits placement of the transducer relative to the transducer structure.

[0023] In any embodiment, the at least one mechanical limiter may surround at least a portion of the periphery of the transducer when the transducer is placed on the transducer structure.

[0024] In any embodiment, the transducer may be flexible so that the transducer can conform to a curved surface.

[0025] In any embodiment, the transducer may be substantially incompressible and inextensible.

[0026] In any embodiment, at least one mechanical restriction may be removable.

[0027] According to another aspect of the present disclosure, there is provided a method of adhering a transducer to a transducer structure, the transducer structure having at least one mechanical constraint, the method comprising: applying an adhesive to an area of ​​the transducer structure; positioning a portion of the transducer in a region such that at least one mechanical constraint fixes at least a portion of the transducer in at least two degrees of freedom; Includes.

[0028] In any embodiment, the region can be a first region and the portion can be a first portion, and the method can include: applying an adhesive to a second region of the transducer structure; positioning a second portion of the transducer in a second region such that at least one mechanical limiter fixes at least a portion of the transducer against movement in at least two degrees of freedom; Further includes:

[0029] In any embodiment, the method further comprises: applying an adhesive to a third region of the transducer structure; positioning a third portion of the transducer in a third region such that at least one mechanical limiter fixes at least a portion of the transducer in at least two degrees of freedom; Further includes:

[0030] In any embodiment, the method may further include applying a crimping force to a portion of the transducer at the region.

[0031] In any embodiment, the at least one mechanical restriction can comprise a plurality of mechanical restrictions.

[0032] In any embodiment, the at least one mechanical limiting member may be removable, and the method may further include removing the at least one mechanical limiting member from the transducer structure.

[0033] In any embodiment, the at least one mechanical restriction can include an elongate member.

[0034] In any embodiment, the method further comprises: applying a crimping force to a portion of the transducer at the region; Machining at least one strain controller into the transducer structure; Further includes:

[0035] In any embodiment, the crimping force can be applied until the adhesive is at least partially cured, and the step of machining the at least one strain controller can occur after the adhesive is at least partially cured.

[0036] These and other aspects and features of various embodiments will be described in further detail below.

[0037] For a better understanding of the described embodiments, and to show more clearly how they may be usefully carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: [Brief description of the drawings]

[0038] [Figure 1] FIG. 2 is a top perspective view of a transducer structure in which a transducer is disposed. [Diagram 2] FIG. 2 is a front perspective view of the transducer structure of FIG. 1. [Diagram 3] FIG. 2 is a bottom perspective view of the transducer structure of FIG. 1. [Figure 4] FIG. 2 is a front perspective view of the transducer structure of FIG. 1. [Figure 5A] FIG. 2 is a top perspective view of the transducer structure of FIG. 1. [Figure 5B] FIG. 2 is a top view of the transducer structure of FIG. 1 without the transducer. [Figure 6A] FIG. 2 is a side view of the transducer structure of FIG. 1 without the transducer. [Figure 6B] FIG. 2 is a bottom view of the transducer structure of FIG. 1 without the transducer. [Figure 7A] FIG. 2 is a front perspective view of the transducer structure of FIG. 1. [Figure 7B] FIG. 2 is a front perspective view of the transducer structure of FIG. 1. [Figure 8A] FIG. 2 is a top view of the transducer structure of FIG. 1 without the transducer. [Figure 8B] FIG. 2 is a top view of the transducer structure of FIG. 1 without the transducer. [Figure 9A] 3 is a perspective cross-sectional view of the transducer structure of FIG. 1 taken along line AA of FIG. 2. [Figure 9B] 3 is a perspective cross-sectional view of the transducer structure of FIG. 1 taken along line BB of FIG. 2. [Figure 9C] 3 is a perspective cross-sectional view of the transducer structure of FIG. 1 taken along line CC in FIG. 2. [Figure 10A]13A-13C illustrate a progressive positioning method for fixing the transducer to the transducer structure. [Figure 10B] 13A-13C illustrate a progressive positioning method for fixing the transducer to the transducer structure. [Figure 10C] 13A-13C illustrate a progressive positioning method for fixing the transducer to the transducer structure. [Figure 10D] 13A-13C illustrate a progressive positioning method for fixing the transducer to the transducer structure. [Figure 11A] FIG. 1 illustrates various escape channels for a transducer structure. [Figure 11B] FIG. 1 illustrates various escape channels for a transducer structure. [Figure 11C] FIG. 1 illustrates various escape channels for a transducer structure. [Figure 12] FIG. 13 is a top perspective view of another transducer structure and transducer. [Figure 13] FIG. 13 is a top perspective view of the transducer structure of FIG. 12. [Figure 14] FIG. 13 is a top perspective view of the transducer structure of FIG. 12 without the transducer. [Figure 15] FIG. 13 is a top view of the transducer structure of FIG. 12. [Figure 16] FIG. 13 is a perspective view of a portion of the transducer structure of FIG. [Figure 17] 15 is a perspective cross-sectional view of the transducer structure of FIG. 12 taken along line DD in FIG. [Figure 18] FIG. 18 is a top perspective view of the transducer structure of FIG. 17. [Figure 19] FIG. 18 is a bottom perspective view of the transducer structure of FIG. 17. [Figure 20] 1 is a flow diagram of a method for bonding a transducer to a transducer structure. [Figure 21A] 1A-1D are top views of a transducer structure at various stages of machining. [Figure 21C] 1A-1D are top views of a transducer structure at various stages of machining. [Figure 21E] 1A-1D are top views of a transducer structure at various stages of machining. [Figure 21B]21B is a cross-sectional view of the transducer structure of FIG. 21A taken along line EE of FIG. 21A. [Figure 21D] 21B is a cross-sectional view of the transducer structure of FIG. 21A taken along line EE of FIG. 21A. [Figure 21F] 21B is a cross-sectional view of the transducer structure of FIG. 21A taken along line EE of FIG. 21A. [Figure 22A] FIG. 13 is a top view of another transducer structure. [Figure 22B] FIG. 22B is a cross-sectional view of the transducer structure of FIG. 22A. [Figure 22C] FIG. 13 is a top view of another transducer structure. [Figure 22D] FIG. 22D is a cross-sectional view of the transducer structure of FIG. 22C. [Figure 23A] FIG. 13 is a front perspective view of another transducer structure including a transducer having alignment marks. [Figure 23B] FIG. 23B is a front perspective view of the transducer structure of FIG. 23A after machining. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0039] The drawings included herein are for the purpose of illustrating various examples of articles, methods, and apparatus in accordance with the teachings herein and are not intended to limit the scope of the teachings in any way.

[0040] Various devices, methods, and configurations are described below to provide examples of embodiments of each claimed invention. None of the embodiments described below limit the claimed invention, and any claimed invention may include devices and methods different from those described below. The claimed invention is not limited to devices, methods, and configurations having all of the features of any one device, method, or configuration described below, or to features common to many or all of the devices, methods, or configurations described below. It is possible that a device, method, or configuration described below is not an embodiment of any claimed invention. Any inventions disclosed in the devices, methods, or configurations described below that are not claimed in this document may be the subject of other means of protection, such as, for example, a continuing patent application, and the applicant, inventor, and / or owner do not intend to abandon, relinquish, or dedicate to the public any such invention by its disclosure in this document.

[0041] Terms such as "an embodiment," "embodiment," "embodiments," "the embodiment," "the embodiments," "one or more embodiments," "some embodiments," and "one embodiment" mean "one or more (but not all) embodiments of the invention," unless expressly specified otherwise.

[0042] "Including," "comprising," and variations thereof mean "including but not limited to," unless expressly specified otherwise. The listing of items does not imply that any or all of the items are mutually exclusive, unless expressly specified otherwise. The terms "a," "an," and "the" mean "one or more," unless expressly specified otherwise.

[0043] As used herein and in the claims, two or more parts are referred to as being "coupled," "connected," "attached," or "fastened" when the parts are connected or operate together directly or indirectly (i.e., through one or more intermediate parts) where a link occurs. As used herein and in the claims, two or more parts are referred to as being "directly coupled," "directly connected," "directly attached," or "directly fastened" when the parts are connected in physical contact with one another. None of the terms "coupled," "connected," "attached," and "fastened" distinguish the manner in which two or more parts are connected together.

[0044] Furthermore, it should be understood that, where considered appropriate, for simplicity and clarity of description, reference numerals may be repeated among the figures to indicate corresponding or similar elements. Additionally, numerous specific details are described to provide a thorough understanding of the exemplary embodiments described herein. However, those skilled in the art will appreciate that the exemplary embodiments described herein may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the exemplary embodiments described herein. Furthermore, this description should not be considered as limiting the scope of the exemplary embodiments described herein.

[0045] As used herein, the term "and / or" is intended to represent an inclusive or. That is, for example, "X and / or Y" is intended to mean either X or Y, or both. As a further example, "X, Y, and / or Z" is intended to mean either X or Y or Z, or any combination thereof.

[0046] As used in this specification and claims, two elements are said to be "parallel" when the elements are parallel and spaced apart, or when the elements are collinear.

[0047] A general description of the transducer structure 1, an exemplary embodiment of a transducer structure 100 is shown that includes a transducer 300. The transducer 300 is disposed on the transducer structure 100 such 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 grating, a silicon strain gauge, a metal foil strain gauge, and / or combinations thereof.

[0048] In some embodiments, the transducer 300 may have multiple strain gauges (not shown). Each strain gauge may be disposed on the measurement surface 110. In use, when the transducer structure 100 is subjected to a pressure force, deformation of the transducer structure 100 causes deformation of one or more of the measurement surfaces 110, inducing a strain in the measurement surface 110. The strain is the ratio of a measured length to an original length in a particular direction. The strain gauges operate to measure the change relative to the measurement surface 110, allowing the deformation to be calculated. For example, if the measurement surface 110 is compressed, the strain value will be less than 1. Conversely, if the measurement surface 110 is stretched, the strain value will be greater than 1.

[0049] Measuring the distortion of the measurement surface 110 caused by the application of a force to the transducer structure 100 allows a user to calculate the value of the applied force that caused the deformation of the measurement surface 110. This calculation can be determined by using known material properties of the transducer structure 100 and by using the known geometry of the transducer structure 100. Thus, by measuring the distortion with a strain gauge, the applied force can be determined.

[0050] 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 in a first direction, a second direction, and a third direction, each of which is perpendicular to one another in a Cartesian coordinate system. These directions are usually referred to as the x, y, and z directions. An exemplary coordinate system 10 is shown in FIG. 1. Each of the three directions has a translation component, a movement along that direction, and a rotation component, a rotation about an axis of that direction. The translation and rotation components produce six degrees of freedom in a Cartesian coordinate system. Thus, an applied force can have six components, namely, Fx, Fy, Fz, Mx, My, and Mz, where F=force and M=moment.

[0051] The applied force may not be applied in one direction relative to the transducer structure 100. The force may be applied at an angle in a first, second, and / or third direction relative to the structure 100, resulting in a resultant force that may be separated into an axial force applied along each direction and a rotational force that creates a moment about each axis. Thus, to measure the exact applied force, the force along each axis can be calculated from the strain values ​​measured for each measurement surface 110.

[0052] The measurement surface 110 can be an elongated member formed to receive the transducer 300. For example, the measurement surface 110 can be a thin beam. To measure force and / or torque, the transducer can be affixed to the elongated beam 112 to measure its relative strain as a result of the net force / torque on the transducer structure 100. For example, the transducer 300 can have multiple strain gauge sensors and multiple elongated beams 112, each with one or more sensors disposed on its respective elongated beam 112, as illustrated in Figures 1 to 10D.

[0053] The transducer 300 may include one or more temperature sensors. The inclusion of a temperature sensor allows for local compensation of an individual transducer. In other words, the temperature sensor may be used in combination with the deformation sensor to compensate for temperature changes and gradients, thereby improving the accuracy of the output data from the transducer 300.

[0054] 1, as shown, the transducer 300 can be a thin film transducer. As illustrated, the transducer 300 can range in thickness from about 25 microns to about 150 microns. It will be appreciated that the transducer 300 can have a thickness ranging from about 500 nanometers to about 500 microns.

[0055] The applied force may be from any application, such as the transducer structure 100 being coupled to an end effector that interacts with one or more objects that induces a deformation in the transducer structure 100. For example, the transducer structure 100 shown in Figure 1 is a finger that may be used to interact with an object and measure the applied force as a result of the interaction. As shown, the transducer structure 100 has multiple couplings 102 for attaching additional end effectors.

[0056] Transducer mounting restrictions relative to the transducer structure The accuracy of placing the transducer 300 at the desired location on the transducer structure 100 can have a large effect on the accuracy of the data measured by the transducer 300, especially if the transducer structure 100 is relatively small. For small scale applications, even if the transducer 300 is misaligned by a few millimeters, the measured data may be inaccurate and / or insensitive, perhaps even to the point where the data is unusable. To compensate for positional errors, the transducer 300 can be calibrated by various adjustments after the transducer 300 is fixed to the transducer structure 100. However, such calibrations can be very time-consuming and expensive, and cannot address the loss in sensitivity. Large scale applications still have increased errors from misalignment of the transducer 300 on the measurement surface 110, but a few millimeters often do not make a resultant data error due to the relative dimensions of the measurement surface 100 to the entire transducer structure 100. Even so, placement of the transducer 300 on the measurement surface 110 should be as accurate as possible to reduce or eliminate calibration costs after the transducer 300 is fixed to the measurement surface 110.

[0057] According to one or more embodiments herein, a transducer structure 100 is provided having at least one mechanical limiting portion 120, as illustrated in FIG. 1. The at least one mechanical limiting portion 120 at least partially limits the placement of the transducer 300 relative to the transducer structure 100. The at least one mechanical limiting portion 120 also serves to fix at least a portion of the transducer 300 in at least two degrees of freedom when the transducer 300 is placed on the transducer structure 100. In other words, the at least one mechanical limiting portion 120 can mechanically hold the transducer 300 in a fixed position, and thus the transducer 300 is restricted from moving in at least two degrees of freedom. As used herein, fixing refers to making substantially not move. By using the at least one mechanical limiting portion 120 to fix the transducer 300 in at least two degrees of freedom, the transducer 300 is made substantially not move in these two degrees of freedom.

[0058] The design of the transducer structure 100 with at least one mechanical limit 120 allows for improved and / or optimized accuracy when positioning the transducer 300 on the measurement surface 110. By optimizing the positional accuracy of the positioning of the transducer 300, subsequent calibration adjustments can be minimized or eliminated. In other words, the use of at least one mechanical limit 120 to fix at least a portion of the transducer 300 in at least two degrees of freedom serves as a form of calibration by design. The advantage of this design is that positional errors can be reduced or eliminated, thereby reducing or eliminating the need for post-application calibration adjustments, saving time and money.

[0059] Furthermore, by designing the transducer structure 100 to constrain the placement of the transducers 300, the design can be used to repeatedly fabricate multiple transducer structures 100 with nearly identical calibration by design function. Thus, the positional accuracy of the transducers 300 on the transducer structure 100 can be repeatedly improved throughout the fabrication process of multiple transducer structures 100, reducing and / or eliminating the need for calibration adjustments.

[0060] It should be understood that errors such as machining errors and accidental positional changes caused by pressing a body against an adhesive surface can result in slight positional inaccuracies of the transducer 300. In such situations, calibration adjustments can be used to adjust for such errors.

[0061] A difficulty with measuring applied forces is that a force applied in a single direction may result in strain output measurements in multiple directions across various sensors. This phenomenon is known as crosstalk. For example, a strain gauge meant to measure strain in the x-direction may be interfered with by a force applied in the y-direction, resulting in an error in the measurement of the x-direction strain gauge that obtains the strain from the applied force. This error may be introduced, for example, by imprecise application of the strain gauge to the transducer structure 100 or by machining tolerances. The transducer structure 100 may be designed to reduce the amount of crosstalk. For example, referring to FIG. 1, the transducer structure 100 has multiple elongated beams 112 designed to facilitate the transfer of forces to the strain gauge in each of the x, y, and z directions to reduce the possibility of crosstalk between two or more directions.

[0062] The at least one mechanical limiter 120 may be any mechanical mechanism that acts to limit placement of the transducer 300 relative to the transducer structure 100 and secures at least a portion of the transducer 300 in at least two degrees of freedom when placed on the transducer structure 100. For example, the at least one mechanical limiter 120 may be, but is not limited to, an elongated member, a groove, a cavity, a mold, a solder paste surface tension adhesive lock.

[0063] The mechanical limiter 120 can be a single mechanical limiter or can be multiple mechanical limiters. As illustrated in Fig. 1, the transducer structure 100 has multiple mechanical limiters 120. Each mechanical limiter 120 can act to limit the placement of the transducer 300 relative to the transducer structure 100 and can fix at least a portion of the transducer 300 in at least two degrees of freedom when placed on the structure.

[0064] The multiple mechanical limiting members 120 can be connected to each other, such as grooves, or can be separated from each other, such as grooves and elongated members. As shown in FIG. 1, the at least one mechanical limiting member 120 is a multiple of mechanical limiting members 120a, 120b, 120c, 120d, 120e. Each mechanical limiting member 120 serves to limit the placement of the transducer 300 on the transducer structure 100 and also fixes at least a portion of the transducer 300 in at least two degrees of freedom. Thus, the mechanical limiting member 120 limits where the transducer 300 can be placed on the structure 100, but also limits the mobility of the transducer 300 after it is placed on the structure 100.

[0065] At least one mechanical limit 120 can limit the placement of the transducer 300 relative to the transducer structure 100 so that the strain sensor is located within a certain tolerance of a desired location. The desired location can vary depending on the desired application of the transducer structure 100. For example, in some embodiments, properly placing the transducer 300 means that the strain sensor is located within 50 microns of the desired location. In some embodiments, the tolerance for error can be, but is not limited to, within a range of about 1 micron to about 0.5 millimeters.

[0066] In some embodiments, the at least one mechanical limiting portion 120 can fix at least a portion of the transducer 300 in at least three degrees of freedom. For example, as shown in FIG. 1, the at least one mechanical limiting portion 120a is a groove in the surface of the transducer structure 100. The groove 120a has a plurality of walls 122 extending from a base 124, and the plurality of walls 122 have a groove height extending from the base 124 to a tip of each wall. The groove 120a forms a key shape in the transducer structure 100 that receives the key portion 310 of the transducer 300. Thus, the key portion 310 can fit into the groove 120a of the transducer structure 100, and thus the placement of the transducer 300 is limited by the groove 120a. In addition, after being placed in the groove 120a, the key portion 310 of the transducer 300 is fixed by the groove 120a such that the movement of the transducer 300 cannot move in three degrees of freedom. As shown, the key portion 310 of the transducer 300 is fixed in translational degrees of freedom x and y, and in rotational degrees of freedom z. In other words, when the key portion 310 of the transducer 300 is placed in the groove 120a of the transducer structure 100, the key portion 310 of the transducer 300 cannot translate in the xy plane or rotate about the z axis. Thus, the transducer 300 is fixed in at least three degrees of freedom.

[0067] The at least one mechanical limiting portion 120 may be formed in any manner that limits the placement of the transducer 300 and fixes it in at least two degrees of freedom. As mentioned above, the groove 120a is keyed to receive the key portion 310 of the transducer 300. As illustrated in FIG. 1, the mechanical limiting portion 120 may be a groove 120b that forms a corner that fixes the transducer 300 in three degrees of freedom. As shown, the groove 120b has a first portion 140 and a second portion 142 spaced apart from the first portion. The transducer 300 is correspondingly formed such 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 against movement in the negative x-direction and the negative y-direction, and the second portion 142 fixes the transducer 300 against movement in the positive x-direction and the positive y-direction. Additionally, because the first portion 140 and the second portion 142 are separated, the two portions prevent the transducer 300 from rotating about the z-axis. Thus, the transducer 300 is fixed in three degrees of freedom.

[0068] The at least one mechanical limiting portion 120 can act to protect the transducer 300 from damage by surrounding at least a portion of the periphery of the transducer 300 when the transducer 300 is placed on the transducer structure 100. By surrounding at least a portion of the periphery of the transducer, the groove 120 can act as a shock absorber 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.

[0069] It should be understood that the groove height can be any dimension depending on the desired use of the transducer structure 100. For example, referring to FIG. 1, the mechanical limit 120e near the front end of the transducer structure 100 is a groove 120e having a larger groove height than the other mechanical limits 120 on the transducer structure 100. This larger groove height can prevent contact damage to the transducer 300 due to the transducer structure 100 intentionally or accidentally contacting a surface. Additionally, the groove can prevent delamination of the transducer 300 from the transducer structure 100.

[0070] As illustrated in Figures 12 to 19, the at least one mechanical limiter 120 is an elongated member 120. The elongated member 120 has a generally triangular cross-sectional shape. The triangular shaped elongated member 120 can thus act to fix at least a portion of the transducer 300 in three degrees of freedom, i.e. translationally in the xy plane and rotationally around the z axis. The transducer 300 has an opening 350 formed to receive the elongated member 120. In other words, as illustrated in Figures 12 to 19, the opening 350 is generally triangular. The mechanical limiter 120 acts to fix a portion of the transducer 300 in three degrees of freedom, but also limits the positioning of the remainder of the transducer 300 along the transducer structure 100. The opening 350 can be of any size and / or shape that can be received by the elongated member 120 such that at least a portion of the transducer 300 is fixed in at least two degrees of freedom.

[0071] As illustrated in Figures 12 to 19, the transducer structure 100 includes three elongated beams 112, each having two measurement surfaces 110. The measurement surfaces 110 are generally perpendicular to each other along each elongated beam 112. Each measurement surface 110 is for receiving a sensing portion 320 of the transducer 300. For example, as shown in Figure 16, each elongated beam 112 has a first measurement surface 110a and a second measurement surface 110b. Each measurement surface 110a and 110b receives a corresponding sensing portion 320a and 320b of the transducer 300, respectively. Thus, there are six sensing portions 320, which can perform measurement of data in six degrees of freedom (Fxyz and Mxyz).

[0072] In some embodiments, the at least one mechanical limiting member 120 may include multiple mechanical limiting members 120 of varying types, shapes, and / or dimensions. For example, referring to FIG. 1, as shown, a first mechanical limiting member 120 is a key-shaped groove 120a for receiving a key portion 310 of the transducer 300, and a second mechanical limiting member 120b is a groove forming a corner. In some embodiments, the transducer structure 100 may include a triangular shaped elongated member 120 and groove 120.

[0073] Response and Sensor Position Proper placement of the transducer 300 on the transducer structure 100 can vary depending on the application of the transducer structure. As previously mentioned, the transducer 300 can have at least one strain sensor. To increase the accuracy of the strain measurement, the strain sensor can be placed near a stress concentration zone on the transducer structure. The size, shape, and / or number of the stress concentration zones can be designed to maximize the dynamic range of the transducer 300 and / or minimize the noise of the output signal. For example, as shown in Figures 1 to 10D, the transducer structure 100 has three stress zones 112. Each stress concentration zone is an elongated beam 112 that forms a measurement surface 110 for receiving a strain sensor. Thus, at least one mechanical limiting member 120 can fix at least a portion of the transducer 300 in at least two degrees of freedom such that each sensor in the transducer 300 is placed near a respective stress concentration zone on its respective elongated beam 112.

[0074] The at least one mechanical limiting portion 120 can act to limit the positioning of the transducer 300 so that the mechanical limiting portion 120 does not interfere with the measurement surface 110. In other words, the fixing of the transducer 300 is performed at a location spaced apart from the measurement surface 110, but the positioning of the transducer 300 is limited so that the strain sensor is properly positioned on the measurement surface 110. For example, as shown in FIG. 1, the at least one mechanical limiting portion 120a is a groove that limits the positioning of the transducer 300 in three degrees of freedom without extending onto the measurement surface 110a located adjacent to the groove 120a. Thus, the groove limits the positioning of the transducer 300 relative to the transducer structure 100 so that the strain sensor is optimally positioned on the elongated beam 112a without compromising the structure of the elongated beam 112a. The advantage of this design is that separating the at least one mechanical limiting portion 120 from the measurement surface 110 reduces and / or prevents the creation of localized stress points on the measurement surface 110. Over time, localized stress points can exacerbate errors due to many cyclic loadings against the measurement surface. For example, if screws are used to hold the transducer 300 in place, the screws can introduce localized stress points that interfere with strain measurements of the elongated beam 112 and can reduce the life of the transducer structure 100.

[0075] In some embodiments, as illustrated in FIG. 1 through FIG. 10D, the transducer structure 100 can be formed from an integral structure. In other words, the transducer structure 100 can be formed from a single material that is machined and / or formed to facilitate placement of the transducer 300 relative to the transducer structure 100. By using an integral structure, the relative positions between the multiple sensors in the transducer 300 can be more easily maintained. The advantage of this design is that the sensitivity of each measurement surface 110 on the transducer structure 100 can be more tightly controlled. For example, referring to FIG. 1, the transducer structure 100 is of an integral structure machined to receive the transducer 300. As previously mentioned, the transducer structure 300 has three elongated beams 112. As shown, each elongated beam 112 is machined from an integral structure.

[0076] In some embodiments, structure 100 can be formed from multiple components that are fastened together to form a single structure. For example, multiple components can include, but are not limited to, being bolted together, laser welded together, and / or epoxied together to form structure 100.

[0077] The structure 100 can include one or more distortion controllers 114 to control the sensitivity of the measurement surface 110 on the structure 100. For example, each elongated beam 112 can be formed with a series of distortion controllers 114 that change the sensitivity of the elongated beam 112. As illustrated, the distortion controllers are kerfs 114 machined into the structure 100 to form the elongated beam 112. Using the kerfs 114 to control the sensitivity of the elongated beam 112 allows for a tunable approach to sensitivity control since the thickness of each kerf 114 can be varied during fabrication depending on the desired sensitivity level of the transducer 300. The sensitivity is determined by the ratio of the kerf width to the length of the elongated beam. Additionally, the distortion controllers 114 can be used to control the overload condition of each beam 112. Using the distortion controllers 114 can convert thick beam portions of the integrated structure into thin beams to increase the sensitivity of the structure 100. For example, the thin beam can range, including but not limited to, from about 300 microns to about 20 millimeters.

[0078] Thus, the transducer structure 100 can be used in applications with a wide range of sensitivities. By designing an adjustable approach to sensitivity control, the transducer structure 100 can be used to handle anything from food to steel, for example. The sensitivity control allows soft foods, such as vegetables or crab-like objects, to be handled by the same transducer structure 100 that is used to handle steel rods.

[0079] The one or more strain controllers 114 can be formed by any fabrication method capable of precision cutting, including, but not limited to, wire EDM and / or laser waterjet. In some embodiments, such as when wire EDM is used, the strain controller 114 can be formed using one or more fabrication methods to drill the starter holes 116 and form the kerfs 114. The starter holes 116 can range from about 0.7 to 1.0 mm, and the thickness of the kerfs 114 can range from about 0.025 mm to about 0.5 mm. It should be understood that the dimensions and thickness will vary with the dimensions of the transducer structure 100. After the starter holes 116 are drilled, the kerfs 114 can be formed, for example, by wire EDM. For example, wire EDM can be used when the thickness of the kerfs 114 is in the range of about 150 microns. In some embodiments, the starter holes 116 may not be necessary. For example, laser waterjet can be used without first forming the starter holes 116. A laser waterjet can be used, for example, when the thickness of the kerf 114 is in the range of less than 150 microns.

[0080] Complex Surface In some embodiments, the transducer structure 100 can be designed to accommodate the transducer 300 across multiple zones 200, and at least one mechanical limiter 120 can fix at least a portion of the transducer in two degrees of freedom across the multiple zones 200. For example, the transducer 300 can have multiple strain sensors, which can determine a known relationship between the location 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 at multiple locations across a complex surface. Additionally, the known location of the sensing portion of the transducer 300 relative to each measurement surface 110 can reduce calibration time and errors.

[0081] As mentioned above, the transducer structure 100 may have three elongated beams 112, each for receiving a strain sensor. Each elongated beam 112 includes a measurement surface 110. As illustrated in FIG. 1, the measurement surface 110a extends between a first zone 200a and a second zone 200b. Each zone 200 is designed to receive a portion of the transducer 300, and thus, when the transducer 300 is placed in a zone 200, the portion of the transducer 300 is fixed in that zone 200 with at least two degrees of freedom. Thus, when all the portions of the transducer 300 are placed on the transducer structure 100, the at least one mechanical limiting portion 120 may act to fix at least a portion of the transducer 300 with respect to each zone 200 in the plurality of zones 200. In some embodiments, the at least one mechanical limiting portion 120 is a plurality of mechanical limiting portions 120 that fix the transducer 300 with respect to each zone 200 in the plurality of zones 200. It should be understood that one or more mechanical constraints 120 can be used with the transducer 300 to measure any number of degrees of freedom. For example, this design can be used with a 3 or 4 degree of freedom robot wrist, a 3 degree of freedom joint in general, a 1 to 3 degree of freedom finger, and / or a structure with more than 4 degrees of freedom.

[0082] In some embodiments, the zones 200 can be a single surface. For example, referring to FIG. 1, the top surface 170 of the transducer structure 100 has a first zone 200a (formed by the key portion of the groove 120a) and a second zone 200b (formed by the corner 120b having the first portion 140 and the second portion 142). The two zones 200 act to fix the first sensing portion 320a therebetween in three degrees of freedom. In other words, the first sensing portion 320a is fixed in the correct position on the first elongated beam 112a so that it extends parallel to the measurement surface 110a when the transducer 300 is placed on the transducer structure 100. Fixing the transducer 300 in the zones 200a and 200b therefore results in the first sensing portion 320a being properly positioned on the measurement surface 110a.

[0083] In some embodiments, the zone 200 can traverse multiple surfaces. For example, referring to FIG. 1, the transducer structure 100 has multiple surfaces for receiving a transducer, namely, a top surface 170, a side surface 172, and a front surface 174. Each surface of the multiple surfaces has a measurement surface 110. As shown, the transducer 300 extends parallel along each surface in the multiple surfaces. To maintain the placement of the transducer 300 relative to the transducer structure 100 across the multiple surfaces, there are multiple zones 200 across the surfaces, each zone formed by one or more mechanical restraints 120. As mentioned above, the top surface 170 has a first zone 200a and a second zone 200b. As illustrated in FIGS. 1 to 7B, the side surface 172 includes a third zone 200c and a fourth zone 200d, and the front surface 174 includes a fifth zone 200e. A third zone 200c is formed by corner groove 120c and a fourth zone 200d is formed by groove 120d. A fifth zone 200e is formed by groove 120e that extends a substantial length of the front surface 174.

[0084] The second sensing portion 320b is fixed in three degrees of freedom on the second measurement surface 110b so that it extends parallel to the side surface 172 when the transducer 300 is placed on the transducer structure 100. The third sensing portion 320c is fixed in position in three degrees of freedom on the third measurement surface 110c so that it extends parallel to the front surface 174 when the transducer 300 is placed on the transducer structure 100. In other words, fixing the zone 200 formed by the multiple mechanical constraints 120 serves to fix the transducer 300 across multiple surfaces, placing each strain sensor in its proper position on its respective measurement surface. As mentioned before, the measurement surface 110 illustrated in FIG. 1 is an elongated beam 112.

[0085] Each mechanical limit 120 in the multiple mechanical limits can act to maintain fixation of the transducer 300 in three degrees of freedom. For example, as shown in Figure 1, each of the first, second, and third sensing portions of the transducer 300 are fixed in the translational x and y planes, and rotational about the z axis. Thus, fixation in three degrees of freedom is maintained across complex surface structures having multiple surfaces.

[0086] The use of multiple mechanical restraints 120 allows each portion of the transducer 300 to be locally fixed on the transducer structure 100. Localized fixation of the transducer 300 can reduce the likelihood of deformation and / or bending of the transducer 300 over large distances across the transducer structure 100. In other words, the transducer 300 can be fixed by each mechanical restraint 120 in each region in a manner that facilitates placement of the transducer 300 across an entire surface or across multiple measurement planes, but minimizes or eliminates damage to the transducer 300.

[0087] To facilitate the extension of the transducer 300 across multiple surfaces, the transducer 300 can be made from a flexible material. For example, as shown in FIG. 1, FIG. 5A, and FIG. 10A-10D, the transducer 300 is flexible to wrap around one or more contoured surfaces. In other words, the transducer 300 can be bent. The flexibility of the transducer 300 allows the transducer 300 to be fabricated on a single plane, yet still allows the transducer 300 to be wrapped around a complex transducer structure 100. Fabricating the transducer 300 on a single plane can reduce fabrication time, cost, and / or error. In some embodiments, the transducer 300 can be substantially incompressible and inextensible. In some embodiments, an extensible transducer 300 can be used to allow the extension of the transducer 300 to be controllable.

[0088] The use of a flexible transducer 300 allows for the fabrication of transducer structures 100 with complex surfaces. The shape of the transducer structure 100 can be customized depending on the desired application of the transducer structure 100. For example, referring to FIG. 1, the transducer structure 100 has multiple mechanical constraints 120 extending along multiple surfaces. The multiple surfaces include rounded edges that allow the transducer 300 to extend from one surface to the next, while minimizing the possibility of damaging the transducer 300.

[0089] Furthermore, using a flexible transducer 300 allows the transducer structure 100 to be fabricated at a range of scales. For example, large scale applications may have more distributed stress concentrations, and therefore precise alignment of the transducer 300 with respect to the stress concentration areas may be less important than small scale applications. In small scale applications, placement of the transducer 300 across multiple surfaces may be difficult and precise placement may be required to properly align the transducer 300 with the stress concentration areas. Using a flexible transducer 300 may improve accuracy, such that the transducer 300 may be placed on the transducer structure 100 across complex surfaces, but maintain the desired placement of the transducer 300 with respect to small stress concentration areas. In other words, small scale applications may inherently make multi-surface transducer applications more complex. Thus, the flexible transducer 300 may reduce errors and improve the accuracy of the transducer structure 100.

[0090] As illustrated, the at least one mechanical limiting portion 120 may be matingly shaped to receive the transducer 300 such that the shape of the at least one mechanical limiting portion 120 limits the placement of the transducer 300 relative to the transducer structure 100. As shown in FIG. 1, the mating shape of the groove 120 extends across multiple surfaces, which allows the use of a single flexible transducer 300 to extend across multiple surfaces. This flexible transducer 300 may conform to curved surfaces. This flexibility may reduce the likelihood of delamination of the transducer 300 from the transducer structure 100 and may make it easier to bond the transducer 300 to the transducer structure 100. Additionally, using curved surfaces may minimize the formation of localized stress zones and reduce the likelihood of stress concentrations in the transducer 300. Stress concentrations in the transducer 300 may result in failure of the transducer 300 due to, but not limited to, tension, bending, kinking, and / or tearing.

[0091] It will be appreciated that the corresponding mating features of the transducer 300 and the transducer structure 100 can be any shape and / or dimension that facilitates placement of the transducer 300 on the transducer structure 100. The mating features can be formed from a number of mechanical restraints 100, including, but not limited to, grooves and / or elongated members.

[0092] In some embodiments, the complex surface of the transducer structure 100 may include a single mechanical constraint 120 that acts to fix a portion of the transducer 300 in three degrees of freedom. As illustrated in Figures 12 to 19, the transducer structure has three elongated beams 112 that form six measurement planes 110. Based on the positional constraints of the elongated members 120, the sensing portions of the transducers 300 are restricted in how they can be positioned on the transducer structure 100, thereby guiding the placement of the transducers 300 relative to the transducer structure 100. In addition, the design of the transducer structure 100 allows the transducers 300 to be placed over a complex surface that includes three elongated beams 112 for sensing in six degrees of freedom.

[0093] Adhesive layer thickness control The structure 100 can be designed to control the thickness of the adhesive bond used to secure the transducer 300 to the transducer structure 100. The adhesive layer thickness refers to the thickness or height of the adhesive above the surface of the transducer structure 100 that receives the adhesive and the transducer 300. The adhesive layer thickness control can also be referred to as vertical alignment because the adhesive layer 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 adhesive layer thickness is an important feature to consider for the design of the transducer structure 100 because it has a direct impact on the response and durability of the transducer 300 when placed on the transducer structure 100. For example, if the adhesive layer thickness is too thin, there may be insufficient volume of adhesive to secure the transducer 300 to the transducer structure 100. If the adhesive bond is too thick, the adhesive may affect hysteresis and may cause a sluggish response of the transducer 300 because the transducer 300 is too far from the measurement surface 110 .

[0094] In some embodiments, at least one mechanical limiter 120 can be used to control the thickness of the adhesive layer. For example, in embodiments where the mechanical limiter is a groove, the groove 120 can be used to control the volume of adhesive that can be accommodated in the groove 120. Controlling the volume of adhesive that can be accommodated in the groove can control the position of the transducer 300 perpendicular to the surface of the transducer structure 100. For example, the groove 120 can provide a desired thickness of the adhesive layer such that when the transducer 300 is adhered to the transducer structure 100, the height of the groove can secure the transducer 300 in place with a specified volume of adhesive between the transducer structure 100 and the transducer 300. In other words, excess adhesive is squeezed out of the groove 120 so that the thickness of the adhesive layer can be within an ideal range of acceptable tolerances.

[0095] At least one mechanical limiter 120, as previously described, can be used to limit the placement of the transducer 300 relative to the transducer structure 100. For example, if an adhesive is applied to the transducer structure 100 and the transducer 300 is applied to the adhesive, the adhesive can cause the transducer 300 to slip or accidentally change position across the surface of the transducer structure 100. The mechanical limiter 120 (e.g., a groove) can reduce or eliminate positional errors caused by adhesive slippage by preventing the transducer 300 from moving within the groove 120.

[0096] The one or more mechanical restraints 120 can prevent adhesive slippage or accidental position change of the transducer 300 across multiple surfaces of the transducer structure 100. For example, when the transducer 300 is bent from one surface to another, at least one mechanical restraint 120 can limit the placement of the transducer 300 such that adhesive slippage is minimized across multiple surfaces.

[0097] It should be understood that the thickness of the adhesive layer may vary depending on the desired application of the transducer structure 100. For example, in some embodiments, the adhesive may be approximately 10 microns thick. The thickness of the adhesive layer may vary depending on factors such as, but not limited to, the viscosity of the adhesive, the surface roughness, and / or the strength of the adhesive.

[0098] In some embodiments, the height of the grooves may be constant across one or more surfaces of the transducer structure 100. For example, if it is desired that the thickness of the adhesive layer be a constant thickness value, the height of the grooves may be constant.

[0099] In some embodiments, the height of the grooves can be variable across one or more surfaces. For example, if a thicker adhesive layer thickness is desired in one or more areas on the transducer structure 100, the adhesive layer thickness in those areas can be increased. The height of the grooves can be used to control the adhesive layer thickness within a tolerance of, for example, about 10 to 50 microns. The tolerance can vary depending on the application of the transducer structure 100. The height of the grooves can be greater than the thickness of the transducer. An advantage of this design is that the grooves can protect the transducer 300 from delamination or other damage.

[0100] In some embodiments, the transducer structure 100 can include at least one channel 180 for controlling the displacement of adhesive when the transducer 300 is bonded to the transducer structure 100. As illustrated in FIG. 1 and FIG. 8A-8B, the transducer structure 100 has an escape channel 180 near the front surface 174 of the transducer structure 100. The escape channel 180 is also near the kerfs 114 that form the elongated beam 112 near the front surface 174. The location of the escape channel 180 relative to the kerfs 114 can control the squeeze-out of adhesive when the transducer 300 is pressed onto the transducer structure 100. In other words, when the transducer 300 is pressed onto the front surface 174, some adhesive can be squeezed out of the groove 120. If adhesive flows into the kerfs 114 that form the elongated beam 112c, the elongated beam 112c will not act as a thin beam since it will be bonded to the rest of the integrated structure of the transducer structure 100. Therefore, any adhesive that is squeezed out and flows into the kerf 114 can cause inaccurate measurements. For example, even a single drop of adhesive that flows into the kerf 114 can significantly affect the accuracy of the transducer measurement.

[0101] It should be understood that at least one channel 180 can extend across one surface, or can extend across multiple surfaces. In some embodiments, there may be multiple channels 180 on and / or within the transducer structure 100.

[0102] In some embodiments, the escape channel can extend completely through the transducer structure 100, as illustrated in FIG. 1. The escape channel or channels may not extend through the entire transducer structure 100, but may alternatively or additionally form pockets 182 for receiving excess adhesive, as illustrated in FIGS. 11A-11C. FIG. 11B(i) illustrates a dangerous failure scenario when adhesive 20 enters the kerfs 114. FIG. 11(ii) illustrates a dangerous failure scenario when not enough adhesive is used to secure the transducer 300 to the transducer structure 100. FIG. 11(iii) illustrates the use of an escape channel 180 that is a pocket for receiving excess adhesive 20. The escape channel or channels 180 can be of any size and / or shape that facilitates containing excess adhesive 20. As illustrated in FIG. 11C, the channel 180 can be a series of pockets for receiving adhesive 20.

[0103] Therefore, designing the transducer structure 100 to control the thickness of the adhesive layer can provide one or more advantages including, but not limited to, controlling the volume of adhesive used, controlling squeezing out during crimping, and / or eliminating fabrication drawbacks by preventing adhesive from flowing to undesirable locations on the transducer structure 100 that may be compromised by the presence of excess adhesive.

[0104] It should be understood that the adhesive can be any material capable of securing the transducer 300 to the transducer structure 100. For example, the adhesive can include, but is not limited to, semi-solid, liquid, pressure sensitive adhesives, epoxies, cyanoacrylates, acrylics, polyurethanes, silica, and / or combinations thereof. The adhesive can be a compound formulated with, but is not limited to, silica, glass, carbide, and / or combinations thereof. In some embodiments, the adhesive can be elastically reinforced. The adhesive can form an adhesive bond, such as, but is not limited to, light, moisture, and / or heat curing. In some embodiments, the adhesive can be both heat and two-part curing epoxies and cyanoacrylates.

[0105] In some embodiments, multiple adhesives can be used on the transducer structure 100. The adhesives can vary for different zones or different components of the transducer structure 100. For example, a first adhesive can be used to secure a portion of the transducer 300 to the elongated beam 112 and a second adhesive can be used to secure the remainder of the transducer 300 to the transducer structure. The first and second adhesives can be any adhesive or combination of adhesives. Using different adhesives for different components of the transducer 300 can improve the speed and repeatability of the fabrication process and can improve the fabrication of more complex, long form factor transducers 300.

[0106] Temporary Mechanical Restrictions In some embodiments, the at least one mechanical limiting member 120 can be temporarily placed on the transducer structure 100. In other words, the at least one mechanical limiting member 120 can be removable from the structure 100. For example, the at least one mechanical limiting member 120 can be an elongated member received in a slot in the transducer structure 100. The elongated member can be used to at least partially limit the placement of the transducer 300 relative to the transducer structure 100 and can fix a portion of the transducer 300 in at least two degrees of freedom when the transducer 300 is placed on the transducer structure 100. After the adhesive that fixes the transducer 300 to the transducer structure 100 has at least partially cured, the elongated member can be removed from the slot on the transducer structure 100.

[0107] As another example, the at least one mechanical limiter 120 can be a stencil placed in contact with the transducer structure 100 and can hold the transducer 300 in place while it is bonded to the structure 100. The stencil can be used to constrain the placement of the transducer 300 relative to the transducer structure 100 and can act to fix at least a portion of the transducer 300 in at least two degrees of freedom. After the adhesive has cured or is mostly cured, the stencil can be removed from the transducer structure 100. The stencil can also be used as a method of controlling the squeeze-out.

[0108] In some embodiments, there may be multiple mechanical restriction members 120, but at least one mechanical restriction member 120 forms a permanent component of the structure 100, and at least one mechanical restriction member 120 is removable from the structure 100.

[0109] Gradual restriction method The method of fixing the transducer 300 to the transducer structure 100 can be done as a progressive constraint formation. In other words, a first portion of the transducer can be fixed before the next portion of the transducer is fixed. In this way, the placement of the transducer 300 relative to the transducer structure 100 can be optimized as previously described, utilizing one or more mechanical constraints 120 to fix a portion of the transducer in place before the remainder of the transducer is fixed to ensure proper placement.

[0110] 20, there is shown a flow diagram of an exemplary method 1000 of adhering a transducer 300 to a transducer structure 100 having at least one mechanical limiter 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 placed in the first region 190 such that the at least one mechanical limiter 120 secures at least a portion of the transducer against movement in at least two degrees of freedom, as illustrated in FIG.

[0111] Optionally, at 1200, adhesive is applied to the second region 192 of the transducer structure 100. At 1210, a portion of a transducer 300 is placed in the second region 192 and at least one mechanical limiter 120 secures at least a portion of the transducer against movement in at least two degrees of freedom, as illustrated in FIG.

[0112] Optionally, at 1300, adhesive is applied to the third region 194 of the transducer structure 100. At 1310, a portion of the transducer 300 is secured to the third region 194 such that at least one mechanical limiter 120 secures at least a portion of the transducer against movement in at least two degrees of freedom, as illustrated in FIG.

[0113] It should be understood that the number of steps for the method 1000 will vary depending on the design of the transducer structure 100 and its complexity. The number of mechanical limiters 120 can also vary. For example, there can be a different mechanical limiter 120 used for each of 1100, 1200, 1300. Alternatively, a single mechanical limiter 120 can be used across multiple regions. The mechanical limiters 120 can be removed, and the method 1000 can also include removing the mechanical limiters 120 from the structure 100 after the adhesive has cured or is mostly cured.

[0114] In some embodiments, the method 1000 can include applying a compression force to one or more portions of the transducer 300 in one or more regions. The compression force can be used to apply pressure to the transducer 300 while the adhesive cures on the transducer structure 100. This compression force can vary with the adhesive material used. In some embodiments, a compression force may not be necessary to properly cure the adhesive. For example, a low viscosity adhesive such as an epoxy may require less or no compression force.

[0115] In some embodiments, the method 1000 can include using multiple adhesives. A first adhesive, such as, for example, an epoxy, can be used to secure the transducer 300 to the transducer structure 100 across the elongate member 112, and a second adhesive, such as, for example, a pressure sensitive adhesive, can be used to bond the remainder of the transducer 300 to the transducer structure 100. It will be appreciated that the multiple adhesives can be any adhesive or combination of adhesives. An advantage of this design is that the fabrication process can be fast and reproducible.

[0116] Production method The method of fabricating the transducer structure 100 and fastening 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 to have one or more strain controllers 114, also referred to as kerfs 114. The kerfs 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. After the transducer structure 100 is fully machined, the transducer 300 may be bonded to the transducer structure 100, as previously described.

[0117] In this embodiment, care must be taken when crimping the transducer 300 to the transducer structure 100 to prevent damage to the measurement surface 110, which is often very thin and can be damaged by the crimping force used to secure the transducer 300 to the transducer structure 100. The damage can be exacerbated by heat when the crimping is performed at high temperatures. The amount of damage caused by the crimping force will depend on the size and strength of the structure 100 and / or the elongated beam 112. For example, a small and / or thin beam 112 is more easily damaged by crimping than a large and / or thick beam 112. To prevent damage to the elongated beam 112, shims can be placed in the kerfs 114 to prevent warping and / or plastic deformation to the beam 112.

[0118] The sensors of the transducer 300 may be aligned to the transducer 300. Thus, if positional errors are introduced into the position of the sensor relative to the measurement surface 110, further calibration may be required to compensate for these errors.

[0119] In some embodiments, the transducer 300 can be secured to the transducer structure 100 before the kerfs 114 are machined into the transducer structure 100. After the transducer 300 is secured to the transducer structure 100, the kerfs 114 can be machined into the structure 100 to form one or more elongated beams 112. The advantage of this method is that the transducer 300 can be safely fastened to the transducer structure 100 before fragile components, such as the elongated beams 112, are machined into the structure 100. In other words, the transducer 300 can be, for example, crimped onto a surface of the transducer structure 100 while minimizing or eliminating damage to the structure 100. After the transducer 300 is safely fastened, more fragile components, such as the elongated members 112, can be machined into the transducer structure 100.

[0120] After the transducer 300 is fixed to the transducer structure 100 and the measurement surface 110 is machined into the structure 100, the position of the transducer 300 can be aligned with the actual position of the transducer 300. The advantage of this process is that the position of the transducer 300 can be aligned more accurately.

[0121] In some embodiments, a conductive machining process can be used to machine the transducer structure 100. For example, as previously mentioned, wire EDM can be used to form the kerfs 114. The conductive machining process cuts through the conductive material without completely or largely touching the non-conductive material. Thus, when the transducer 300 is secured to the transducer structure 100 before the kerfs 114 are machined, wire EDM can be used to cut the kerfs 114 while minimizing or eliminating damage to the transducer 300. Using conductive machining on the conductive surfaces of the transducer structure 100 with the non-conductive transducer 300 allows for very precise machining while avoiding damage to the transducer 300. The transducer 300 can be made from a material that can withstand autoclave sterilization, thereby further reducing damage from the machining process.

[0122] In some embodiments, the transducer 300 may include at least a portion made from a conductive material. For example, the transducer 300 may include copper traces that may guide a conductive machining process. Thus, the conductive machining process used to machine the measurement surface 110 may also be used to cut the transducer 300. The conductive components of the transducer 300 may be positioned to avoid damage to sensitive components of the transducer 300, such as sensors.

[0123] In some embodiments, alignment marks can be used to improve the tolerance of placement of the transducer 300 relative to the transducer structure 100. For example, in embodiments in which the transducer 300 is applied to the transducer structure 100 before machining the measurement surface 110, alignment marks on the transducer 300 can guide where the kerfs 114 should be machined so that the transducer 300 is aligned in the proper position on the transducer structure 100.

[0124] As mentioned before, if the kerfs 114 are machined before the transducer 300 is fixed, care can be taken to avoid adhesive contacting the kerfs 114. As illustrated in Figs. 22A and 22B, if the kerfs 114 are machined before the transducer 300 is placed on the transducer structure 100, the edges of the transducer 300 can be spaced apart from the kerfs 114. As shown, squeeze-out of the adhesive 20 extends beyond the edges of the transducer 300. Thus, the space between the kerfs 114 and the transducer 300 can be designed to reduce the chance of adhesive 20 getting into the kerfs 114. Even a single drop of adhesive in the kerfs 114 can significantly affect the performance of the transducer 300. Alternatively, the kerfs 114 can be machined after the transducer 300 is already bonded to the transducer structure 100. Therefore, by machining the kerfs 114 after the transducer 300 is bonded to the transducer structure 100, squeeze-out problems that could damage the kerfs 114 can be avoided.

[0125] In other words, when adhering the transducer 300 to the transducer structure 100, a compression force may be applied to a portion of the transducer 300 against the transducer structure 100 to apply pressure to the adhesive 20. The compression force may be applied until the adhesive 20 cures. After the adhesive 20 cures, the strain controller 114 may be machined into the structure 100. It should be understood that the level of cure prior to the machining process may vary depending on the adhesive used.

[0126] If the transducer 300 is applied to the transducer structure 100 after the kerfs 114 are machined, the relative position of the sensor on the transducer 300 with respect to the measurement surface 110 may be slightly offset, for example, due to positional errors previously discussed. Additionally, the pressure used to apply the transducer 300 to the structure 100 may damage sensitive components, such as the measurement surface 110. Thus, by fastening the transducer 300 to the transducer structure 100 before the kerfs 114 are machined, and by using a conductive machining method, the kerfs 114 may be formed with minimal or no damage to the transducer structure 100, may minimize or no damage from crimping, may improve tolerances using, for example, alignment marks on the transducer 300, and / or may further reduce and / or no calibration requirements.

[0127] 21A-21F, the transducer 300 has alignment marks 360. The alignment marks 360 can be used to identify where the sensor is to be placed in the transducer 300 and / or where the measurement surface should be placed on the structure 100 so that the kerfs 114 can be machined in the desired location. In some embodiments, the transducer 300 can have multiple alignment marks 360. The alignment marks 360 can be used to provide a visual indication of any type of machining or positioning process for the transducer 300 and / or transducer structure 100.

[0128] After the transducer 300 is secured to the surface of the transducer structure 100 (FIGS. 21C and 21D), a machining method such as wire EDM can be used to cut through the alignment marks 360 (FIGS. 21E and 21F). By indicating the desired cutting location of the kerf 114 relative to the transducer 300, positional errors can be reduced. Another advantage of this design is that it can be repeated across multiple transducer structures 100 to reduce errors.

[0129] In some embodiments, the transducer 300 can have one or more additional portions, including an alignment mark 360. The additional portion can be used to overlap an area on the transducer structure 100 to provide a visual indication of where to machine the structure 100. In other words, the transducer 300 can be designed to include a portion that specifically guides the machining of the transducer structure 100. For example, as shown in FIG. 23A, the transducer 300 has an alignment mark 360 that overlaps with the top of the transducer structure 100. The transducer 300 is placed on the side of the structure 100 with an overlapping portion that extends to the top surface. As illustrated in FIG. 23B, the alignment mark 360 is machined to form the measurement surface 110.

[0130] It should be understood that the alignment mark 360 may be partially or completely cut during the machining process. For example, in some embodiments, the alignment mark 360 may indicate where the kerf 114 should be placed, and the kerf 114 may extend only partially along the length of the alignment mark 360.

[0131] In some embodiments, the alignment marks 360 can be used to provide a visual indication of possible misalignment. As illustrated in Figures 22C and 22D, an error was introduced during machining of the kerfs 114. The error is indicated by misalignment of the alignment marks 360 with respect to the kerfs 114, whereby the alignment marks 360 were only partially cut. The error could have been introduced, for example, by machining errors, transducer fabrication errors, laser misalignment, and / or photomask misalignment, etc. The visual indication of the misalignment can be used to assist a user in calibration or can indicate that the structure 100 needs to be replaced.

[0132] Although the above description describes features of exemplary embodiments, it will be understood that some features and / or functions of the described embodiments may be modified without departing from the spirit and principles of operation of the described embodiments. For example, various features described by the illustrated embodiments or examples may be selectively combined with each other. Thus, what has been described above is intended to be illustrative and non-limiting of the claimed concepts. Those skilled in the art will appreciate that other variations and modifications may be made without departing from the scope of the invention as defined in the claims appended hereto. The claims should not be limited by the preferred embodiments and examples, but should be given the broadest interpretation consistent with this description as a whole. [Explanation of symbols]

[0133] 10 Coordinate Systems 20. Glue 100 Transducer structure 102 Coupling 110 Measurement surface 110a,b Measuring surface (1st, 2nd) 112 Slender beams, stress concentration zones 112c Narrow Beam 114 Knife, Distortion Controller 116 Starting hole 120 Mechanical Restriction Part 120a~e Mechanical restriction section 122 Wall 124 Base 140 First Part 142 Second Part 170 Top 172 Side 174 Front 180 Escape Channel 182 Pocket 190 First Area 192 Second Area 194 The Third Region 200 Zone 200a~e Zone (1st~5th) 300 Transducer 310 Key part 320 Sensing part 320a, b, c Sensing part (1st, 2nd, 3rd) 350 opening 360 Alignment Mark

Claims

1. 1. A transducer structure comprising: at least one mechanical limiting portion configured to receive the transducer such that the at least one mechanical limiting portion at least partially limits placement of the transducer relative to the transducer structure; A transducer structure, wherein the at least one mechanical limiting portion fixes at least a portion of the transducer in at least two degrees of freedom when the transducer is disposed on the transducer structure.

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

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

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

5. 10. The transducer structure of claim 1, wherein the transducer has a plurality of zones, and the at least one mechanical limiter fixes the transducer in at least two degrees of freedom across the plurality of zones.

6. 10. The transducer structure of claim 1, wherein the at least one mechanical limit comprises at least one corner that limits the transducer in a Cartesian plane and in a plane of revolution.

7. 2. The transducer structure of claim 1, wherein the at least one mechanical limiting portion includes a groove having a plurality of walls extending from a base, the groove having a groove height extending from the base to a top of each of the plurality of walls.

8. The transducer structure of claim 7 , wherein the groove height is greater than the thickness of the transducer.

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

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

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

12. 2. The transducer structure of claim 1, wherein the at least one mechanical limiting portion comprises a plurality of mechanical limiting portions, the transducer structure comprises a plurality of surfaces, and the plurality of mechanical limiting portions fix the transducer in at least two degrees of freedom across each surface of the plurality of surfaces.

13. 10. The transducer structure of claim 1, wherein the at least one mechanical limiting portion comprises at least one channel for controlling the displacement of an adhesive when the transducer is bonded to the transducer structure.

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

15. 10. The transducer structure of claim 1, further comprising a distortion controller for controlling a sensitivity of said transducer when said transducer is disposed on said transducer structure.

16. 16. The transducer structure of claim 15, wherein the strain controller is at least one kerf in the transducer structure forming an elongated member in which the transducer can be positioned.

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

18. 2. The transducer structure of claim 1, wherein the at least one mechanical limiting portion is matingly shaped to receive the transducer such that a shape of the at least one mechanical limiting portion substantially limits placement of the transducer relative to the transducer structure.

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

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

21. 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 limiting portion is removable.

23. 1. A method for bonding a transducer to a transducer structure, the transducer structure having at least one mechanical constraint, the method comprising: applying an adhesive to an area of ​​the transducer structure; positioning a portion of the transducer in the region such that the at least one mechanical limiter fixes at least a portion of the transducer in at least two degrees of freedom; A method comprising:

24. the region is a first region and the portion is a first portion, and the method further comprises: applying the adhesive to a second region of the transducer structure; positioning a second portion of the transducer in the second region such that the at least one mechanical limiter fixes at least a portion of the transducer against movement in at least two degrees of freedom; 24. The method of claim 23, further comprising:

25. applying the adhesive to a third region of the transducer structure; positioning a third portion of the transducer in the third region such that the at least one mechanical limiter fixes at least a portion of the transducer in at least two degrees of freedom; 25. The method of claim 24, further comprising:

26. 24. The method of claim 23, further comprising applying a crimping force to the portion of the transducer at the region.

27. The method of claim 23 , wherein the at least one mechanical restriction comprises a plurality of mechanical restrictions.

28. 24. The method of claim 23, wherein the at least one mechanical limiting member is removable, the method further comprising the step of detaching the at least one mechanical limiting member from the transducer structure.

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

30. applying a crimping force to the portion of the transducer at the region; machining at least one strain controller into said transducer structure; 24. The method of claim 23, further comprising:

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

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