Three-dimensional flexible compliant array tactile sensor with multimodal sensing and scalable manufacturing method

Abstract

This invention provides a three-dimensional (3D) tactile sensor and a method for manufacturing the same. [Solution] The method includes the steps of: preparing a first substrate material for a 3D tactile sensor; defining a set of first conductive regions for the 3D tactile sensor on the first substrate material; forming a stack by bonding a separator layer between the first substrate material containing the set of first conductive regions and a second substrate material having a set of second conductive regions; and forming the stack according to a desired 3D structure. The substrate material may include a flexible polymer, and the conductive regions may be defined by processes such as screen printing, etching, laser direct structuring, pad printing, or 3D adhesion. The separator layer may include a dielectric material or a piezoresistive material. The 3D tactile sensor can conform to curved geometric shapes and may be used to measure surface force, contact, and pressure.

Description

Technical Field

[0001] [Cross-Reference to Related Patent Applications] This application claims priority to U.S. Provisional Application No. 63 / 783,580 filed on April 4, 2025, the entire contents of which are incorporated herein by reference for all purposes.

[0002] The present disclosure relates to tactile sensing systems, and specifically to three-dimensional (3D) soft compliant tactile sensors capable of measuring surface forces, contact and pressure over curved geometries.

Background Art

[0003] Tactile sensors are used to detect physical interactions such as contact, force and pressure in various environments. Achieving high spatial resolution and mechanical compliance in tactile sensing remains challenging.

[0004] Conventional rigid two-dimensional (2D) tactile sensors lack the ability to conform to curved or irregular geometries, which may result in reduced sensitivity or unreliable detection of contact, force or pressure in various applications. For example, as autonomous robotic systems become more widespread, tactile sensors need to conform to the contours or geometries of robotic devices.

Summary of the Invention

Means for Solving the Problems

[0005] The technology described herein provides a three-dimensional (3D) tactile sensor capable of measuring surface forces, contact, and pressure across an entire curved geometry. Such sensors can be used in a variety of applications, including but not limited to robotic systems or automation systems. For example, the 3D tactile sensors described herein may be used in fingertips, palms, end effectors, or other parts of a robot that enable the robot to sense the world around it. The sensors may be defined using flexible or moldable materials such as thermoplastics and can support the detection of resistance or capacitance. The 3D tactile sensors described herein can be manufactured using a variety of methods. One exemplary method involves defining an array of sensing elements in a substrate material using screen printing or substrate etching. Further methods include the use of 3D distribution (e.g., 3D printing) technology, pad printing technology, or electroplating technology. The substrate may be formed into a target 3D geometry using any suitable technology, in particular thermoforming, injection molding, or compression molding.

[0006] At least one embodiment relates to a method that includes the step of preparing a first substrate material for a three-dimensional tactile sensor. The method may include the step of defining a set of first conductive regions for the three-dimensional tactile sensor on the first substrate material. The method may include the step of bonding a separator layer between a first substrate material containing a set of first conductive regions and a second substrate material having a set of second conductive regions in order to generate a stack. The method may include the step of forming the stack into a desired three-dimensional structure.

[0007] In some implementations, the step of preparing a first substrate material may include the step of selecting a first substrate material from thermoplastic polyurethane, polyethylene terephthalate, or polyimide. In some implementations, the step of defining a set of first conductive regions may include the step of placing conductive ink on the surface of the first substrate material, the conductive ink forming a set of first conductive regions. In some implementations, the step of placing the conductive ink may include the step of using a screen printing process and stencils to define the trace pattern for the three-dimensional tactile sensor.

[0008] In some implementations, the step of defining a pair of first conductive regions may include etching channels in a first substrate material corresponding to a wiring pattern for a three-dimensional tactile sensor, and providing conductive material within the channels. In some implementations, the step of etching channels may include cutting a portion of the first substrate material using a laser. In some implementations, the method may further include providing a cover layer on the conductive material, wherein the cover layer exposes at least a portion of the conductive material. In some implementations, the method may further include merging a flexible printed circuit board to at least a portion of a pair of first conductive regions. In some implementations, the step of forming a stack into a target three-dimensional structure may include thermoforming the stack using a mold for the target three-dimensional structure.

[0009] At least one other embodiment relates to a method that can be performed, for example, by one or more processors connected to non-temporary memory. The method may include the step of forming a first substrate material according to a target three-dimensional structure for a three-dimensional tactile sensor. The method may include the step of defining a set of first conductive regions for a three-dimensional tactile sensor on the first substrate material. The method may include the step of providing a separator material on at least a portion of the set of first conductive regions. The method may include the step of bonding a second substrate material having a set of second conductive regions to a separator material, wherein the second substrate material conforms to the three-dimensional structure of the first substrate material.

[0010] In some implementations, the step of forming a first substrate material according to a target three-dimensional structure may include the step of thermoforming a layer of the first substrate material using a mold corresponding to the target three-dimensional structure of the three-dimensional tactile sensor. In some implementations, the step of defining a set of first conductive regions may include the step of depositing one or more conductive wirings onto the surface of the first substrate material using a three-dimensional distribution process. In some implementations, the step of defining a set of first conductive regions may include the step of defining one or more activated regions on the surface of the first substrate material and the step of plating one or more activated regions with a conductive material.

[0011] In some implementations, the step of defining one or more activation regions may include using a laser according to a wiring pattern for a three-dimensional tactile sensor. In some implementations, the step of defining a pair of first conductive regions may include providing one or more conductive wirings on the surface of a first substrate material using a pad printing process. In some implementations, the step of providing separator material may include attaching separator material to a portion of a pair of first conductive regions using a three-dimensional distribution process. In some implementations, the step of providing separator material may include bonding a layer of dielectric material to the first substrate material to cover a pair of first conductive regions. In some implementations, the method may further include attaching either the first or second substrate material to a backing material.

[0012] At least one embodiment relates to a three-dimensional tactile sensor that may include a stacked body comprising a first layer of a substrate material having a pair of first conductive regions, a separator material bonded to the first layer of the substrate material, and a second layer of the substrate material having a pair of second conductive regions separated from the pair of first conductive regions by the separator material. The stacked body is thermoformed to conform to the desired three-dimensional structure.

[0013] In some implementations, the separator material includes either a dielectric material or a piezoresistive material.

[0014] These and other embodiments and implementations are described in detail below. The information above and the detailed description below, including illustrative examples of various embodiments and implementations, provide an overview or framework for understanding the nature and features of the claimed embodiments and implementations. The drawings, which illustrate and further illustrate various embodiments and implementations, are incorporated herein and constitute part of this specification. The embodiments can be combined, and it will be readily apparent that features described in the context of one embodiment of the invention can be combined with those of other embodiments. Where used herein and in the claims, the singular “a,” “an,” and “the” refer to multiple subjects unless otherwise explicitly indicated in the context. [Brief explanation of the drawing]

[0015] Non-limiting embodiments of this disclosure are described as examples relating to the accompanying drawings, which are schematic and not intended to be drawn to scale. Unless otherwise indicated as representing the background art, the drawings represent aspects of this disclosure.

[0016] [Figure 1] This is a diagram showing a robot hand equipped with a 3D soft compliant array tactile sensor according to one embodiment.

[0017] [Figure 2] This is a perspective view showing a 3D tactile sensor attached to a support material according to one embodiment.

[0018] [Figure 3] This flowchart shows a method for manufacturing a 3D tactile sensor by generating a layered body and applying a thermoforming process thereto, according to one embodiment.

[0019] [Figure 4A] This is a diagram illustrating a 3D screen printing process for defining conductive ink on a substrate material used to generate the 3D tactile sensor described herein, according to one embodiment. [Figure 4B] Diagram illustrating, according to one embodiment, a 3D screen printing process for defining conductive ink on a substrate material used to produce the 3D tactile sensor described herein. [Figure 4C] Diagram illustrating, according to one embodiment, a 3D screen printing process for defining conductive ink on a substrate material used to produce the 3D tactile sensor described herein.

[0020] [Figure 4D] Top view showing a substrate having screen-printed conductive regions for a 3D tactile sensor formed using the techniques shown in Figure 4A, Figure 4B and Figure 4C, according to one embodiment.

[0021] [Figure 4E] Cross-sectional view of a layer stack comprising a substrate material and the conductive regions of Figure 4D bonded to a separator material, according to one embodiment.

[0022] [Figure 5A] Diagram illustrating an exemplary process for forming a layer stack using an etching process, according to one embodiment. [Figure 5B] Diagram illustrating an exemplary process for forming a layer stack using an etching process, according to one embodiment. [Figure 5C] Diagram illustrating an exemplary process for forming a layer stack using an etching process, according to one embodiment. [Figure 5D] Diagram illustrating an exemplary process for forming a layer stack using an etching process, according to one embodiment. [Figure 5E] Diagram illustrating an exemplary process for forming a layer stack using an etching process, according to one embodiment.

[0023] [Figure 6]This is a diagram showing a thermoforming process for forming a layered body formed by the technology described herein, according to one embodiment.

[0024] [Figure 7] This is a cross-sectional view showing a 3D tactile sensor after the thermoforming process shown in Figure 6, according to one embodiment.

[0025] [Figure 8] This flowchart shows a method for manufacturing a 3D tactile sensor according to one embodiment, by forming a conformal base substrate and attaching conductive wiring and separator material thereon.

[0026] [Figure 9] This is a diagram showing a 3D distribution process for forming conductive wiring on a formed substrate material according to one embodiment.

[0027] [Figure 10A] This is a diagram illustrating a process for defining a conductive region on a substrate material formed using a laser, according to one embodiment. [Figure 10B] This is a diagram illustrating a process for defining a conductive region on a substrate material formed using a laser, according to one embodiment.

[0028] [Figure 11A] This is a diagram illustrating a process for defining a conductive region on a substrate material formed using a pad printing process, according to one embodiment. [Figure 11B] This is a diagram illustrating a process for defining a conductive region on a substrate material formed using a pad printing process, according to one embodiment.

[0029] [Figure 12A] This is a diagram illustrating a 3D distribution process for forming a separator material on a defined conductive region on a substrate material, according to one embodiment.

[0030] [Figure 12B] This is a diagram showing a 3D tactile sensor formed after the attachment of a separator material, as shown in Figure 12A, according to one embodiment. [Modes for carrying out the invention]

[0031] Next, with reference to the exemplary embodiments shown in the drawings, and using specific terminology in this specification to describe them, however, it will be understood that no limitation of the claims or the scope of this disclosure is intended thereto. Any changes and further modifications to the features of the invention shown herein, as well as any further applications of the principles of the subject matter shown herein, that a person skilled in the art who owns this disclosure would conceive, should be considered within the scope of the subject matter disclosed herein. Other embodiments may be used and / or other modifications may be made without departing from the spirit or scope of this disclosure. The exemplary embodiments described in the detailed description are not intended to limit the subject matter presented.

[0032] Tactile sensing systems, such as those in robotic systems, may use force or pressure sensors to measure contact with the physical environment. For example, tactile sensing can be used in robotic end effectors, wearable devices, or other aspects of automated systems that interact with physical objects or the environment. Existing tactile sensors are limited to two-dimensional (2D) flat configurations that do not mechanically conform to 3D geometry. Therefore, such rigid 2D sensors cannot be used in a variety of robotics applications, including end effectors, robotic hands, or those requiring sensors on other curved surfaces. Existing flexible tactile sensors lack mechanical stability and are unsuitable for many applications.

[0033] The techniques described herein may be used to manufacture 3D tactile sensors, not limited to rigid 2D geometry, while providing mechanical stability suitable for robots or automation systems. Tactile sensors manufactured using such techniques may include both resistive and capacitive sensors. To manufacture such sensors, a flexible array of conductive regions may be defined on a moldable substrate material. The conductive regions may be defined using any suitable technique, but are not limited to screen printing, conductive paste deposition, laser direct structuring, or pad printing. The moldable substrate material may be bonded to a separator material which may include a dielectric material for capacitive sensors or a piezoresistive material for resistive sensors. The separator material may separate complementary layers of the substrate material, each defined according to the desired capabilities and area of ​​the sensor.

[0034] A 3D tactile sensor may be defined as a capacitive sensor or a resistive sensor. A capacitive sensor may include conductive regions located on a substrate layer separated by a dielectric separator material. The substrate and dielectric separator material may be flexible (conformable) so that, in response to an applied force, the dielectric separator material can compress and reduce the distance between conductive regions on the substrate layer. A change in distance results in a change in capacitance. A resistive sensor operates similarly using a piezoresistive separator material. A piezoresistive separator material can change resistance in response to mechanical deformation. In response to an applied force, the piezoresistive separator material can deform so that the electrical resistance between conductive regions on the substrate layer decreases. Changes in resistance or capacitance can be detected by a readout circuit electrically coupled to the conductive regions of the sensor.

[0035] Thermoforming may be used to conform layers of substrate and separator material to a desired 3D geometry. The desired 3D geometry may be a desired shape or contour of a robot or automation system. For example, the layered structure constituting a tactile sensor may be formed according to the 3D geometry of a robot's palm, fingers, or end effector. The layered structure constituting the 3D sensor may be formed to conform to the outer layer of a robot housing, for example, to act as a tactile "skin" for a humanoid robot. Using any suitable technique, the sensors described herein can be formed into any geometry suitable for any application, including tactile sensors.

[0036] In some implementations, the 3D tactile sensors described herein may be formed to the desired 3D geometry before defining conductive regions in the substrate material. For example, a layer of substrate material may first be defined by thermoforming, molding, or other means to conform to the desired 3D geometry of the tactile sensor. Plating (e.g., electroplating) or deposition (or deposition, coating, or coating) techniques may be used to define conductive regions for the sensor on the surface of the formed substrate material. A separator material, which may contain a dielectric material or a piezoresistive material, can then be defined on the conductive regions (e.g., as a layer, by deposition, etc.). Another layer of substrate material, which may have a corresponding pair of conductive regions, may be bonded to the separator material or defined on the separator material to form the sensor. Additional layers of substrate material may be formed or deposited according to any of the techniques described herein.

[0037] The sensors described herein include connectors coupled to conductive regions formed on a layer of substrate material, and the sensors may be manufactured to connect to appropriate circuits that detect changes in the electrical properties of the sensors and detect contact, pressure, or force applied to the sensors. Such connectors may include zero-insertion-force (ZIF) connectors, an anisotropic conductive film coupled to the sensor, or solder that bonds the sensor to a flexible printed circuit board (PCB). In some implementations, the connectors may be coupled to one or more conductive regions using a lamination process, or may be partially formed while defining conductive regions on the substrate material.

[0038] A 3D tactile sensor manufactured according to the technology described herein may be mounted on a support material. In some mounting configurations, the 3D tactile sensor may be mounted on a rigid substrate with a plastic or metal base. In some mounting configurations, the 3D tactile sensor may be mounted on a soft substrate such as foam, thermoplastic elastomer, or silicone material by overmolding or bonding, so that the 3D tactile sensor maintains mechanical compliance. One or more protective layers may be applied over the 3D tactile sensor after it has been mounted on the support material. The protective layer may be made of a flexible or pliable material such as foam, and can protect the sensor from environmental factors, mechanical wear, or impact.

[0039] Referring to Figure 1, a diagram is shown illustrating a robot hand 100 including a set of 3D tactile sensors 102A, 102B, and 102C (sometimes collectively referred to as "3D tactile sensors 102") in one or more implementation configurations. In this example, the first tactile sensor 102A is positioned along the thumb area of ​​the robot hand 100. The first tactile sensor 102A conforms to the geometry of the thumb, as shown in the figure. The second tactile sensor 102B is positioned in the palm area of ​​the robot hand 100. The second tactile sensor 102B may be positioned to cover a substantial portion of the palm surface so as to be able to detect tactile interactions occurring in the palm.

[0040] The third 3D tactile sensor 102C is shown as being positioned on the index finger of the robot hand 100. Additional sensors similar to the 3D tactile sensor 102 can be positioned on any part of the robot hand 100. While this example shows the 3D tactile sensor 102 being provided on the robot hand 100, it should be understood that the various sensors described herein may be positioned on any type of surface for any suitable application. The 3D tactile sensor 102 may include one or more connectors, contacts, or connections to a circuit used to monitor the electrical characteristics of the circuit (e.g., capacitance, resistance, etc.). Each of the 3D tactile sensors 102 may include any number of “pixels” or regions that can independently detect physical contact.

[0041] In some implementations, the 3D tactile sensor 102 may be incorporated into a flexible “skin” layer covering a robot, an autonomous vehicle, or any other type of system operating in an environment to detect physical contact or pressure events. The 3D tactile sensor 102 may be manufactured according to the techniques described herein so as to conform to the 3D structure on which it is mounted, while occupying any suitable area. The 3D tactile sensor 102 may be coupled to one or more support materials that provide the structure of the 3D tactile sensor 102. Further details of exemplary support materials for the 3D tactile sensor described herein will be discussed in reference to Figure 2.

[0042] Referring to Figure 2, a perspective view 200 is shown of an exemplary 3D tactile sensor 202 mounted on a support material 204 in one or more mounting configurations. The 3D tactile sensor 202 may be manufactured using any of the techniques described herein, including the techniques described in relation to method 300 in Figure 3 and method 800 in Figure 8. The 3D tactile sensor 202 may be similar to the 3D tactile sensors 102A, 102B, or 102C of Figure 1, and may include any of their structures or implement any of their functions. The 3D tactile sensor 202 may be one or more capacitive sensors or resistive sensors, or may include them.

[0043] As shown in the figure, the 3D tactile sensor 202 has a curved shape that conforms to the geometry of the support material 204. In some implementations, the 3D tactile sensor 202 may be bonded to the support material 204 by methods such as bonding, overmolding, or mechanical fastening. For example, the 3D tactile sensor 202 may be bonded to the support material 204 using a suitable layer of adhesive. In another example, the 3D tactile sensor 202 may be placed on the support material 204 and overmolded (e.g., using thermoforming or a similar method) to conform the 3D tactile sensor 202 to the support material 204 and bond it there. In some implementations, the 3D tactile sensor 202 may be attached to the support material 204 by mechanical fasteners.

[0044] The support material 204 may include materials selected based on desired mechanical properties or application requirements. In some implementations, the support material 204 may be formed from a rigid material such as rigid plastic or metal. In some implementations, the support material 204 may be formed from a soft or flexible material, in particular, such as foam, thermoplastic elastomer (TPE), or silicone. When using a rigid material, the support material 204 may be manufactured by molding, thermoforming, or machining processes. When using a soft or flexible material, the support material 204 may be manufactured by injection molding (casting), molding, or molding processes (e.g., thermoforming).

[0045] The 3D tactile sensor 202 is shown bonded to a protective layer 206. The protective layer 206 may include, in particular, materials such as foam, thermoplastic polyurethane (TPU), silicone, or TPE. The protective layer 206 may be formed by any suitable process, including, but not limited to, overmolding, bonding, injection molding, or attachment via one or more connectors or fasteners. In some implementations, the protective layer 206 may be attached as a conformal coating or laminated as a material layer. The protective layer 206 may or may not have a constant thickness. In some implementations, the protective layer 206 can provide a barrier against moisture, dust, mechanical wear, or other external factors that may affect the operation of the 3D tactile sensor 202. The material of the protective layer 206 may be selected so as to maintain the mechanical compliance of the 3D tactile sensor 202. In some implementations, the protective layer 206 may be patterned to expose a selected area of ​​the 3D tactile sensor 202 for an electrical interface or to allow direct contact with the target surface.

[0046] Referring to Figure 3, a flowchart of Method 300 for manufacturing one or more 3D tactile sensors in one or more mounting configurations is shown. Method 300 may be performed to generate a layered structure in which layers of substrate material containing conductive regions defining detection positions are separated by separator material. The layered structure may then be molded or otherwise formed to conform to the desired 3D geometry of the 3D tactile sensor. Method 300 may be performed to generate any of the 3D tactile sensors described herein, including but not limited to the 3D tactile sensors 102A, 102B, and 102C in Figure 1 and the 3D tactile sensor 202 in Figure 2. To briefly outline Method 300, Method 300 may include the steps of: preparing a first substrate for a sensor (step 305); defining a set of first conductive regions for a sensor on the first substrate (step 310); bonding a separator layer between the first substrate and a second substrate having a set of second conductive regions (step 315); and forming the first substrate, the second substrate and the separator layer into a desired structure (step 320).

[0047] Method 300 may include, in step 305, preparing a first substrate for the sensor. In some implementations, the first substrate may be provided as a layer that can serve as a basis for defining conductive regions. The first substrate material may be selected from a group of flexible or moldable materials, particularly thermoplastic materials, such as TPU, polyethylene terephthalate (PET), or polyimide. The first substrate may be provided in the form of a sheet or film so that the surface of the first substrate can receive conductive ink, conductive paste, or other conductive material in subsequent processing steps. In some implementations, the first substrate may be subjected to a surface treatment, such as plasma treatment or corona treatment, to modify the surface adhesion properties before defining the conductive regions.

[0048] In some implementations, a layer or film of the first substrate material may be cut or etched to predetermined dimensions before a conductive area is defined thereon in a subsequent step. For example, the first substrate material may be cut by mechanical cutting, die cutting, chemical etching, or laser cutting, among other cutting methods. The predetermined dimensions may be determined according to the desired 3D geometry of the 3D tactile sensor. The layer or film of the first substrate material may be cut to a shape corresponding to the 3D structure it conforms to. In some implementations, the first substrate may be cut or otherwise modified, in particular to include alignment holes, channels, or notches, in order to facilitate subsequent assembly steps or attachment or mounting to other substrates, components, or structures.

[0049] Method 300 may include, in step 310, defining a pair of first conductive regions for a sensor on a first substrate. The pair of first conductive regions may include wiring or patterned features that define the sensing area of ​​the 3D tactile sensor. In a subsequent step of Method 300, the conductive regions defined on the first substrate may be aligned with corresponding conductive regions on a second substrate layer, and the first and second substrate layers are separated by a separator material. In some implementations, the separator material may include a dielectric material, which can create a capacitance sensor between the conductive regions on the first and second layers of the substrate material. In some implementations, the separator material may include a piezoresistive material, which can create a resistance sensor between the conductive regions on the first and second layers of the substrate material. In some implementations, a pair of first conductive regions can be defined on the first substrate using any of the techniques described in relation to step 810 of Method 800 in Figure 8.

[0050] The first conductive region may be positioned to coincide with a location on a first substrate material where tactile sensing is to be performed. In some implementations, the first conductive region may include wiring to connect to one or more external circuits or connectors so that electrical signals can be transmitted to a circuit capable of detecting force, contact, or pressure events based on changes in the electrical properties of the sensing region (e.g., other parts of the conductive region). In some implementations, a set of first conductive regions may be defined by depositing conductive ink onto the surface of the first substrate using a screen printing process. The conductive ink may be deposited using other types of printing processes, such as 3D printing / deposition techniques. Exemplary processes for defining conductive regions using a screen printing process are shown in Figures 4A, 4B, 4C, and 4D.

[0051] Referring to Figures 4A, 4B, 4C, and 4D, diagrams 400A, 400B, 400C, and 400D are shown illustrating exemplary 3D screen printing processes for defining conductive inks on a substrate material used to produce the 3D tactile sensors described herein in one or more mounting configurations. In Figure 4A, diagram 400A is shown as comprising a screen printing system having a printing chuck 402, a screen mesh 406, a screen frame 408, at least one conductive ink 410, a blade, and a stencil film 414. The screen printing process may be used to define one or more areas of the conductive ink 410 on the substrate material 404.

[0052] To perform screen printing, a layer of substrate material 404 for a 3D tactile sensor may be placed on a printing chuck 402 in a screen printing system. As described herein, the substrate material 404 may include a polymer such as TPU, PET, or polyimide. The substrate material 404 may be provided on a flat sheet that can be cut or etched to a predetermined size or shape. The layer of substrate material 404 may be positioned such that the top surface of the substrate material 404 faces the screen mesh 406. A stencil film 414 may be placed between the screen mesh 406 and the layer of substrate material 404. The stencil film 414 may include a pattern of openings corresponding to a desired arrangement of conductive areas on the substrate material 404. The stencil film 414 may include openings or holes that define the geometry, position, or dimensions of conductive wiring and sensing elements formed on the substrate material 404.

[0053] The screen printing process may include applying one or more types of conductive inks 410. The conductive ink 410 may be any type of ink capable of conducting electricity (e.g., having a conductivity of the desired magnitude), and non-limiting examples of conductive inks 410 include silver nanoparticle inks, silver flake inks, carbon inks, copper inks, etc. In some implementations, the conductive ink 410 may be formulated to provide a desired viscosity, particle size distribution, or conductivity suitable for screen printing on a substrate material 404. First, the conductive ink 410 may be distributed onto the upper surface of the screen mesh 406 so that the conductive ink can be transferred through patterned openings in a stencil film 414 using a blade 412. The blade 412 may be used to spread the conductive ink 410 across the entire screen mesh 406 so that the conductive ink 410 is extruded through the stencil film 414 and adhered onto the substrate material 404 in a pattern defined by the stencil film 414.

[0054] Figure 4B shows the next stage of the screen printing process, where a blade 412 is used to extrude conductive ink 410 through patterned openings in the stencil film 414. In some implementations, the blade 412 may be moved on the screen mesh 406 at a predetermined angle to the substrate material 404 so that the conductive ink 410 passes uniformly through the stencil pattern. The blade 412 may be moved on the screen mesh 406 while maintaining a constant downward pressure so that the conductive ink 410 adheres to the substrate material 404 according to the geometry defined by the stencil film 414. In some implementations, the blade 412 may be reciprocated or moved in a nonlinear motion to facilitate the transfer of conductive ink 410 through the openings in the screen mesh 406 and the stencil film 414. The blade 412 may be moved using an actuator, manual force, or a combination thereof.

[0055] In Figure 4C, diagram 400C shows the arrangement of the components of Figures 4A and 4B after the screen printing process for defining conductive regions 416 on the surface of the substrate material 404. As shown, after the conductive ink 410 has passed through the screen mesh 406, the screen frame 408 can be lifted upward and removed from the surface of the printing chuck 402. The resulting conductive regions 416 can form wiring and sensing elements on the top surface of the substrate material 404 so that the substrate material 404 can be used in subsequent assembly steps for the manufacture of a 3D tactile sensor. Any number or pattern of conductive regions 416 can be defined on the surface of the substrate material 404. In some mounting configurations, the conductive regions may define connection regions for one or more connectors that will be coupled to the substrate material 404. An exemplary top view of the substrate material 404 is shown in Figure 4D.

[0056] In Figure 4D, diagram 400D shows a top view of the substrate material 404 on which the conductive regions 416 are arranged. In this example, the conductive regions 416 are arranged as a set of elongated wires extending parallel to each other across the entire surface of the substrate material 404. The conductive regions 416 may be arranged to correspond to the sensing positions of a three-dimensional tactile sensor so that each conductive region 416 can function as an electrode or sensing element. In some implementations, the arrangement of the conductive regions 416 may be determined according to the target spatial resolution or sensing geometry of the 3D tactile sensor. Conductive regions 416 corresponding to different sensing elements or wires may be electrically insulated from each other on the surface of the substrate material 404 so that each conductive region 416 can be monitored by an external circuit. Although parallel conductive regions 416 are shown in Figure 4D, it should be understood that any number, arrangement, or pattern of conductive regions 416 can be provided on the surface of the substrate material 404.

[0057] Referring back to step 310 of method 300 in Figure 3, in some implementations, a set of first conductive regions may be defined by etching or cutting one or more channels into a first substrate using a laser beam or mechanical cutting process. A conductive paste can be deposited into the channels using a suitable distribution process. The conductive paste may be a silver-derived paste and may be cured or dried to form conductive regions on the substrate material. In some implementations, the channels defined in the substrate material may correspond to a desired pattern of wiring or sensor regions. In some implementations, one or more portions of the substrate material may be processed to facilitate bonding with the conductive paste. Connectors or exposed pads may be bonded to the conductive regions or formed as part of the conductive regions to facilitate connection to one or more external sensing circuits. Exemplary processes for defining conductive regions using conductive paste are shown in Figures 5A, 5B, 5C, 5D, and 5E.

[0058] Referring to Figures 5A, 5B, 5C, 5D, and 5E, diagrams 500A, 500B, 500C, 500D, and 500E are shown illustrating exemplary processes for fabricating one or more layers of a 3D tactile sensor. In Figure 5A, diagram 500A shows a layer of substrate material 502 and a corresponding cover layer 504. As described herein, the substrate material 502 may include, in particular, polymers such as TPU, PET, or polyimide. The substrate material 502 may be supplied in the form of a sheet or layer and may be cut to the desired shape or dimensions of the 3D tactile sensor. In some implementations, the cover layer 504 may contain the same material as the substrate material 502 or may contain a different flexible material (e.g., a polymer). The cover layer 504 may be cut or formed to match the dimensions or geometry of the substrate material 502 so that it may be laminated onto the substrate material 502 or otherwise bonded in a subsequent process step.

[0059] In Figure 5B, diagram 500B shows the formation of channels 510 in the substrate material 502. In some implementations, the laser device 506 may include, but is not limited to, a carbon dioxide laser, a fiber laser, or a diode-pumped solid-state laser. The laser device 506 can deliver a focused laser beam 508 controlled to etch the channels 510 in the substrate material 502 according to the wiring pattern for the 3D tactile sensor. The laser beam 508 may be guided along a predetermined path specified by a control command. The path may indicate coordinate and depth information for etching one or more channels 510 in the substrate material 502. In some implementations, the laser device 506 can automatically adjust the output, pulse duration, and / or scanning speed based on the thickness or type of the substrate material 502. For example, certain substrate materials 502 may require additional cutting time or energy to form channels 510 compared to other substrate materials 502. A channel 510 may be formed by cutting an opening through a sheet of substrate material 502 with a laser beam, and then laminating the sheet of substrate material 502 onto a solid sheet of the same substrate material 502.

[0060] In some implementations, channels 510 can be formed in the substrate material 502 using other etching or cutting techniques. For example, a chemical etching process can be performed by attaching a patterned mask to the substrate material 502 and exposing selected areas to a chemical etchant. In some implementations, a mechanical cutting process can be performed using a blade or rotary tool to define the channels 510. For example, a computer numerical control (CNC) cutting machine with an appropriate number of degrees of freedom may be used to mechanically cut out one or more of the channels 510 from the substrate material 502. The cover layer 504 can be etched or cut using similar techniques to provide one or more openings to expose one or more portions of conductive areas to be formed in subsequent process steps. In this example, the openings in the cover layer 504 are shown to be cut using a laser device 506 having a corresponding laser beam 508. The openings can correspond to the electrical contact areas of a 3D tactile sensor.

[0061] In Figure 5C, diagram 500C shows the adhesion of conductive paste 512 (sometimes referred to as “conductive material 512”) within channels 510 defined in a substrate material 502. In some implementations, the substrate material 502 may undergo a surface treatment process after the creation of the channels 510 but before the conductive paste 512 is adhered. The surface treatment may include, in particular, plasma treatment, corona discharge, or chemical priming so that the substrate material 502 is modified to improve adhesion before the conductive paste 512 is adhered. In some implementations, the substrate material 502 may be heated or exposed to ultraviolet light to further alter the surface energy of the channels 510. The type of surface treatment used may depend on the type of substrate material 502 used to generate the 3D tactile sensor, if any.

[0062] The conductive paste 512 may include any type of conductive material that can be spread within the channel 510 or otherwise provided. Non-limiting examples of the conductive paste 512 include, in particular, a gallium-indium alloy, a silver nanoparticle dispersion, a carbon-based paste, or a copper-based paste. The conductive paste 512 may be applied to the channel 510 and spread through the channel using a nozzle distribution system, a spray system, or a blade / squeegee. For example, a nozzle distribution system can supply a controlled amount of conductive paste 512 into the channel 510 according to a predetermined path. The nozzle distribution system may include a 3D printer or similar device that can distribute material to specified locations. In another example, a spray system can apply droplets of conductive paste 512 in a pattern that conforms to the geometry of the channel 510. Similarly, a squeegee may be used to push the conductive paste 512 into the channel 510 by applying pressure along the length of the channel 510, using a technique similar to that described in relation to Figure 4B. Next, in order to define a conductive area on the surface of the substrate material 502, the conductive paste 512 may be dried or cured using an appropriate curing process.

[0063] In Figure 5D, diagram 500D shows a cover layer 504 aligned on the surface of the substrate material 502. In some mounting configurations, the cover layer 504 may be laminated onto the substrate material 502 using a process such as bonding or pressure lamination. The cover layer 504 may be positioned such that one or more openings etched / cut through the cover layer 504 are aligned portions of the conductive material 512 placed on the substrate material 502 to be exposed. The lamination process may be performed under controlled temperature and pressure conditions so that the cover layer 504 adheres to the substrate material 502 without moving the conductive material 512. The cover layer 504 may be aligned with the top surface of the substrate material 502 using one or more mounting brackets or fixtures.

[0064] In some implementations, additional conductive material 512 can be distributed to openings in the cover layer 504 before or after the lamination process. The additional conductive material 512 may be deposited to fill exposed areas and provide electrical conductivity between conductive channels in the substrate and any external components, which can be bonded to the cover layer 504 in subsequent process steps. Deposition of the additional conductive material 512 may be performed using any of the dispensing processes described herein. In some implementations, the surface of the additional conductive material 512 may be treated after curing to facilitate bonding to other components in subsequent process steps.

[0065] In Figure 5E, diagram 500E shows a flexible PCB bonded to the surface of a cover layer 504 in contact with an exposed portion of the conductive paste 512. The flexible PCB 514 may include exposed wiring or pads aligned with the exposed portion of the conductive material 512. The exposed wiring or pads can make electrical contact with the conductive material 512. The flexible PCB 514 may be placed on top of the cover layer 504 and, in particular, may be bonded to the cover layer 504 using adhesives, lamination processes, or mechanical fasteners. In some mounting configurations, as shown, an additional substrate material layer 516 may be provided above the flexible PCB 514 to encapsulate or protect the flexible PCB 514 and at least a portion of the substrate material 502.

[0066] In some implementations, exposed wiring on the flexible PCB 514 can be aligned with the exposed portions of the conductive material 512 based on the geometry of the openings in the cover layer 504 and the layout of the conductive material 512 within the substrate material 502. Alignment can be performed using an optical alignment system or a mechanical alignment bracket / jig. The flexible PCB 514 can be electrically coupled to an external circuit that can monitor or detect changes in the conductivity or capacitance of the conductive material 512 within the 3D tactile sensor. In some implementations, the flexible PCB 514 may include one or more connectors that can be coupled to wires or cables connected to additional control circuits for the 3D tactile sensor.

[0067] Referring back to Figure 3, Method 300 may include, in step 315, bonding a separator layer between a first substrate and a second substrate having a second set of conductive regions. In some mounting configurations, steps 305 and 310 of Method 300 may be repeated to define conductive regions on two layers of substrate material. The second substrate may be similar to the first substrate and may be formed according to any of the techniques described herein. In some mounting configurations, the first and second layers of the substrate (having corresponding conductive regions) may be formed using different techniques (e.g., screen printing, adhesion of conductive paste, etc.). The first and second substrates may be aligned so as to form sensing elements when the conductive regions on each substrate layer are separated by the separator layer. Sensing elements (e.g., pixels) may be portions of the conductive regions of the overlapping substrate layers.

[0068] In some implementations, when the tactile sensor operates in capacitive sensing mode, the separator layer may include a dielectric material. The dielectric material can be any type of flexible dielectric that provides electrical insulation between conductive regions of the substrate layer. In implementations where the 3D tactile sensor is a resistive sensor, the separator layer may include a piezoresistive material. The piezoresistive material may include, but is not limited to, flexible materials such as carbon-containing silicone, conductive elastomer, or conductive foam. The resistance of the piezoresistive material can vary depending on the applied force. The separator layer may be bonded between the first and second substrates by adhesive, lamination, thermal bonding, or any other bonding technique to form a layered structure. An exemplary outline of such a layered structure is described in relation to Figure 4E.

[0069] Referring to Figure 4E, a cross-section 400E of the 3D tactile sensor is shown from the viewpoint of line segment AA' shown in Figure 4D. In this example, the upper substrate material 404 can be a substrate constructed according to the techniques described in relation to Figures 4A to 4E. A conductive region 416 may be placed on the surface of the substrate material 404 and can define sensing electrodes and / or wiring for the 3D tactile sensor. A separator material 422 is shown as being placed between the substrate material 404 and the lower substrate material 418. The separator material 422 may include a dielectric material or a piezoresistive material, as described herein. The thickness of the separator material 422 (e.g., the distance between the upper substrate material 404 and the lower substrate material 418) may be selected to obtain a target reference capacitance or reference resistance in the 3D tactile sensor.

[0070] The lower substrate material 418 may be constructed using techniques similar to those used to construct the upper substrate material 404. The lower substrate material 418 is shown to include one or more lower conductive regions 420 that may be positioned to correspond to conductive regions 416 on the substrate material 404. The upper conductive region 416 and the lower conductive region 420 are shown to be in contact with the separator material 422, but in some configurations, the upper conductive region 416 and the lower conductive region 420 may be defined within the upper substrate material 404 and the lower substrate material 418, respectively, and may not necessarily be in contact with the separator material 422. In some configurations, the separator material 422 may electrically insulate the conductive region 416 from the lower conductive region 420. The stack formed by the substrate material 404, conductive region 416, separator material 422, lower substrate material 418, and lower conductive region 420 may be formed to conform to the desired 3D geometry, as will be described in more detail herein.

[0071] Referring back to Figure 3, Method 300 may include a step in step 320 of forming a stack of a first substrate, a second substrate, and a separator layer, the stack being formed into a desired structure. In one example, the stack can be formed into a desired 3D geometry by applying a thermoforming process, in which the stack is heated to a temperature higher than the glass transition temperature of the substrate material and pressed into a mold defining the desired 3D shape. In another example, the stack may be formed by compression molding, in which the stack is placed between two mold surfaces and subjected to pressure and heat to conform to the contour of the mold. In yet another example, the stack may be formed by vacuum forming, in which the stack is heated and attracted to the mold surface by applying vacuum pressure to conform to the geometry of the mold. An exemplary diagram of the thermoforming process is shown in Figure 6. A 3D tactile sensor obtained from an exemplary thermoforming process is shown in Figure 7.

[0072] Referring to Figure 6, a diagram of a thermoforming system 600 for molding a 3D compliant tactile sensor is shown. The thermoforming system 600 may include a heater housing 604, a heat source 606, a sensor mold 608, or a mold base 610. As shown, the laminated body 602 (e.g., the material laminate shown in Figure 4E) is coupled to the heater housing 604 and can receive heat generated by the heat source 606. The sensor mold 608 is positioned within the mold base 610 such that the sensor mold 608 defines a surface contour corresponding to the desired 3D geometry of the laminated body 602. The mold base 610 may be coupled to the sensor mold 608 so that the sensor mold 608 is fixed in place. As shown, openings may be provided in one or more parts of the sensor mold 608 or the mold base 610 to facilitate the thermoforming process.

[0073] To thermoform the stacked mass 602, heat from a heat source 606 may be applied to the stacked mass 602. In some implementations, the heat source 606 may apply positive air pressure to the top of the stacked mass 602 to facilitate the thermoforming process. To press the heated stacked mass 602 against the sensor mold 608, the heater housing 604 may be lowered or the mold base may be raised. The stacked mass 602 may be heated to its glass transition temperature so that it conforms to the geometry of the sensor mold 608. The heat source 606 may be stopped and the stacked mass 602 may be cooled on the sensor mold 608. The formed stacked mass 602 may then be removed from the sensor mold 608. When cooled below the threshold temperature, the resulting layered body 602 can retain the 3D shape defined by the sensor mold 608, which corresponds to the target 3D structure of the 3D tactile sensor. A 3D tactile sensor formed using the technique described herein is shown in Figure 7.

[0074] Referring to Figure 7, a cross-section of an exemplary 3D tactile sensor 700 is shown. The 3D tactile sensor 700 can be formed into a layered structure similar to the layered structure shown in Figure 4E after the thermoforming process. The 3D tactile sensor 700 includes a lower substrate material 702, a lower conductive region 704, an upper substrate material 706, an upper conductive region 708, and a separator material 710. In this example, the 3D tactile sensor 700 is formed into a curved structure. Following thermoforming, the arrangement of the lower conductive region 704 and the upper conductive region 708 defined in the lower substrate material 702 and upper substrate material 706 is maintained so as to face each other and separated by the separator material 710. This makes it possible to operate the 3D tactile sensor after it has been formed into the desired 3D geometry.

[0075] In some implementations, the 3D tactile sensor 700 may be cut or etched into the desired shape after a thermoforming process. For example, the 3D tactile sensor 700 may be shaped using a mechanical cutting tool, die-cutting apparatus, or laser cutting system to define an outer profile that conforms to the desired geometry. After the cutting or etching process, the 3D tactile sensor 700 may be mounted on a support material (e.g., support material 204 in Figure 2). The mounting process may include bonding, overmolding, or mechanical fastening to secure the 3D tactile sensor to a rigid or flexible support, as described in relation to Figure 2. In some implementations, one or more layers of protective material (e.g., protective layer 206) may be provided on top of the 3D tactile sensor 700.

[0076] Referring to Figure 8, a method 800 for manufacturing a 3D tactile sensor is shown. Method 800 may be performed to generate a 3D tactile sensor on a substrate pre-formed to a desired 3D geometry. Various techniques may be used to define conductive regions on the surface of the formed substrate. Method 800 may be performed to generate any of the 3D tactile sensors described herein, including but not limited to the 3D tactile sensors 102A, 102B, and 102C in Figure 1 and the 3D tactile sensor 202 in Figure 2. Briefly outlining Method 800, it may include the steps of: forming a first substrate according to a desired structure for the sensor (step 805); defining a first conductive region for the sensor on the first substrate (step 810); providing a separator material on at least a portion of the first conductive region (step 815); and bonding a second substrate having a second conductive region to the separator material (step 820).

[0077] Method 800 may include, in step 805, forming a first substrate according to a desired structure for a sensor. The first substrate may be selected using a method similar to that described in step 305 of Method 300 in Figure 3, where a flexible or moldable substrate material can be provided in the form of a sheet or film. In one example, the first substrate may be formed into a desired 3D structure for a 3D tactile sensor by subjecting the substrate material to a thermoforming process. The thermoforming process may include heating the substrate material to a temperature above its glass transition temperature and injecting the substrate material into a mold defining the desired 3D geometry. The substrate material may be cooled so that the substrate maintains its formed shape. In some implementations, the first substrate may be formed into a desired 3D structure by using a molding process such as injection molding or compression molding. In another exemplary implementation, the first substrate may be formed by injecting a liquid precursor of the substrate material into a mold and curing the material to obtain the desired geometry. Mechanical forming techniques may be used to form the substrate material. For example, the first substrate may be formed by machining or cutting a bulk material into a desired 3D shape.

[0078] Method 800 may include defining a pair of first conductive regions for a sensor on a first substrate in step 810. As described herein, the first conductive regions may include patterned wiring or electrodes that can function as sensing elements for a 3D tactile sensor. The first conductive regions may be used to detect changes in the electrical properties (e.g., resistance or capacitance) of the 3D tactile sensor in response to contact, force, or pressure applied to the 3D tactile sensor. In some implementations, a pair of first conductive regions can be defined on a first substrate using any of the techniques described in relation to step 310 of Method 300 in Figure 3. In one example, the first conductive regions may be defined by depositing a conductive material onto the surface of the formed substrate using a 3D dispensing technique. The 3D dispensing technique may include dispensing a conductive ink or paste along a predetermined pattern on a curved surface of the substrate. An exemplary diagram showing 3D dispensing for forming a conductive region is shown in Figure 9.

[0079] Referring to Figure 9, a diagram 900 is shown illustrating a 3D distribution process for forming conductive wiring on a formed substrate material in one or more mounting configurations. Diagram 900 shows a distribution head 906 that forms a set of conductive regions 904 on the formed substrate material 902. The distribution head 906 may include any type of distribution device. For example, the distribution head 906 may include a nozzle-type dispenser or syringe pump. In some mounting configurations, the distribution head 906 may be part of a CNC system or gantry system (e.g., a 3D printer) that can operate according to control signals specifying the distribution path and distribution speed. The conductive regions 904 may be formed using conductive inks or pastes such as silver nanoparticle ink, silver flake ink, carbon-based ink, or gallium-indium alloy paste.

[0080] The conductive ink or paste may be dispensed in a liquid or semi-liquid state and, after being deposited onto the formed substrate material 902, may undergo a curing or sintering process. In some configurations, a dispensing head 906 can be moved over the formed substrate material 902 based on a predetermined pattern so that conductive regions 904 are deposited on the surface of the formed substrate material 902 in a specified arrangement. In some configurations, the predetermined pattern may correspond to any suitable electrode layout for a grid, array, or tactile sensor array. The dispensing process may be repeated over multiple regions of the formed substrate material 902 to generate multiple isolated conductive regions 904 corresponding to different wiring or sensing elements.

[0081] Referring back to step 810 of method 800 in Figure 8, in another example, a first conductive region may be defined by activating a selected area of ​​the substrate using a laser in a laser-direct structuring process. The laser-direct structuring process may include scanning a laser beam across the substrate to activate portions of the substrate material, followed by plating the activated regions with a conductive metal such as copper, nickel, or gold. To activate portions of the substrate material, the laser beam can be directed along a predetermined pattern so that the substrate material is selectively activated in areas corresponding to the desired conductive regions. The activated substrate may be immersed in a plating bath containing a metal salt solution. An exemplary laser-direct structuring process for forming a conductive region is shown in Figures 10A and 10B.

[0082] Referring to Figures 10A and 10B, diagrams 1000A and 1000B are shown illustrating a laser direct structuring process for forming conductive regions on a formed substrate material 1002. In Figure 10A, diagram 1000A shows a laser 1006 that forms one or more activated regions 1004 on the formed substrate material 1002. The formed substrate material 1002 may contain one or more additives to facilitate laser direct structuring. For example, the substrate material 1002 may contain one or more metal-organic compounds. In some implementations, the formed substrate material 1002 may be surface-treated before laser activation. The laser 1006 can include any type of laser capable of activating additives in the substrate material 1002. The laser 1006 can generate a laser beam 1008 having a predetermined wavelength that can be directed onto the formed substrate material 1002 to activate regions for subsequent plating. The laser beam 1008 can be scanned across the entire surface of a substrate material 1002 that is formed according to a predetermined pattern such that the activated region 1004 corresponds to the layout of conductive wiring or electrodes for a three-dimensional tactile sensor.

[0083] In Figure 10B, diagram 1000B shows the substrate material 1002 after a plating process, where the activated regions 1004 are plated with metal to form conductive regions 1010. In one example, the plating process may include immersing the activated substrate material 1002 in a metal plating bath (e.g., copper, nickel, or gold salt solution). When the activated regions 1004 are exposed to the plating bath, metal ions are selectively deposited on the activated regions 1004. In another example, the plating process may include electroplating, in which case a potential may be applied between the activated substrate material 1002 and a counter electrode so that metal ions from the plating bath can adhere to the activated regions 1004. In some implementations, a combination of chemical plating and electroplating may be used, in which case an initial metal layer can be chemically deposited on the activated regions 1004, and then the metal layer can be thickened using electroplating. The resulting conductive regions 1010 may correspond to a pattern of activated regions 1004 on the surface of the activated substrate material 1002.

[0084] Referring back to step 810 of method 800 in Figure 8, in some implementation configurations, a first conductive region can be defined by using a pad printing process to transfer a conductive ink or paste onto a formed substrate material. The pad printing process may include transferring a patterned layer of conductive ink from an etched printing plate to the 3D surface of the substrate material using a silicone pad that can conform to the geometry of the substrate. The pad printing process may be used to apply a conductive pattern to a curved, concave, or irregular surface of the formed substrate material. Conductive inks used in the pad printing process may include, in particular, silver nanoparticle inks, silver flake inks, or carbon inks. In some implementation configurations, the pad printing process may be repeated to deposit multiple layers of conductive ink or to form different electrode patterns on the three-dimensional surface of the substrate material. An exemplary pad printing process for forming a conductive region is shown in Figures 11A and 11B.

[0085] Referring to Figures 11A and 11B, diagrams 1100A and 1100B are shown illustrating the demarcation of conductive regions on a formed substrate material 1106 using a pad printing process. In Figure 11A, diagram 1100A shows a pad printer 1102 having a print head 1104 which can be used to apply conductive ink 1108 onto the surface of the formed substrate material 1106. In some configurations, the conductive ink 1108 may include silver nanoparticles, silver flake-based inks, or carbon-based inks, as described herein. In some configurations, the patterned conductive ink of the pad printer 1102 may be applied from an etched printing plate to the print head 1104. The print head 1104 can transfer the conductive ink 1108 onto the formed substrate material 1106 so that the conductive regions conform to the 3D geometry of the substrate.

[0086] In Figure 11B, diagram 1100B shows the formed substrate material 1106 after the transfer of the conductive ink 1108. As shown, the conductive ink 1108 can conform to the three-dimensional geometry of the formed substrate material 1106. In some implementations, after the transfer of the conductive ink 1108, a curing process can be carried out to adhere the conductive ink 1108 to the surface of the formed substrate material 1106. The resulting structure may include conductive regions for forming wiring or sensing elements on the curved or irregular surface of the formed substrate material 1106. As will be described in more detail herein, additional layers can be bonded to the surface of the substrate material 1106 to form a 3D tactile sensor.

[0087] Referring back to Figure 8, Method 800 may include, in step 815, providing a separator material on at least a portion of the first conductive region. The separator material may include a dielectric material for a capacitive sensor, or a piezoresistive material in the case of a resistive sensor. In one example, the separator material may be defined using a 3D distribution process. In some implementations, the separator material may be deposited as a continuous layer over the entire substrate material using, for example, a thermoforming process or similar forming technique. The thickness and coverage of the separator material may be controlled according to the desired electrical properties of the 3D tactile sensor. An exemplary process for forming the separator material using a 3D distribution technique is shown in Figure 12A.

[0088] Figure 12A shows diagram 1200A of a 3D distribution process for forming separator material on a conductive region of a substrate material. Diagram 1200A shows a distribution head 1206 adhering a region of separator material 1208 to the surface of the substrate material 1202 and the conductive region 1204. In some implementations, the distribution head 1206 may include a nozzle-type dispenser, a syringe pump, or any other type of printing system. The distribution head 1206 may be coupled to and positioned by a CNC system, a robotic arm, or a gantry-type positioning system. The distribution head 1206 may receive a control signal specifying the distribution speed or distribution pressure to adhering a predetermined amount of separator material 1208. Different distribution parameters may be used for different types of separator material 1208.

[0089] Regions of separator material 1208 may be positioned in predetermined locations on the surface of substrate material 1202 and on at least a portion of the conductive region 1204 to define a sensing element. In some mounting configurations, the distribution head may be fixed in place, and the substrate material 1202 may be coupled to a gantry or other positioning system to move the substrate material 1202 to a predetermined position under the distribution head 1206. In this example, the separator material 1208 is shown as being attached to various spots on the surface of the conductive region. As will be described in more detail herein, electrodes may be defined by coupling a second substrate having other conductive regions on the opposite side of the separator material 1208. The separator material 1208 may include a dielectric material for a capacitive sensor or a piezoresistive material for a resistive sensor. Any suitable pattern or amount of separator material 1208 may be attached to the surfaces of the conductive region 1204 and the substrate material 1202.

[0090] In some implementations, the separator material 1208 may include an adhesive material so that the separator material 1208 can be bonded to the substrate material 1202. For example, the separator material 1208 may be provided as a pressure-sensitive adhesive or a heat-activated adhesive. In some implementations, the separator material 1208 may be attached as a film. In some implementations, the adhesive material may be first attached to the substrate material 1202, and then the separator material 1208 may be attached or bonded to the substrate material 1202 via the adhesive material. In another example, the separator material 1208 may be laminated on the substrate material 1202 (for example, in the form of layers or sheets). A combination of multiple methods may be used to bond the separator material 1208.

[0091] Referring back to Figure 8, method 800 may include, in step 820, bonding a second substrate having a second conductive region to a separator material. In some configurations, the second substrate may be positioned such that the separator material is placed between the first and second substrates and bonded to them. The separator material can electrically insulate a first conductive region defined on the first substrate from a second conductive region defined on the second substrate. The second conductive region may correspond to and overlap the first conductive region, where the overlapping conductive regions (separated by the separator material) can form a sensing element. The sensing element may be a capacitive sensor structure or a resistive sensor structure, as described herein. In some implementation configurations, the separator material may be an adhesive material such as a pressure-sensitive adhesive or a heat-activated adhesive, or may include such an adhesive material, which can join the first substrate and the second substrate while maintaining electrical insulation between the conductive regions of the first substrate and the second substrate.

[0092] The second substrate may be manufactured using techniques similar to those described in relation to steps 305 and 310 of method 300 in Figure 3. For example, the second substrate may be provided as a flexible film of TPU, PET, or polyimide, and the second conductive region may be defined on the second substrate using a screen printing process or a process that includes the deposition of conductive ink within channels (e.g., those described in relation to Figures 5A to 5E). In some mounting configurations, the second substrate may be formed into the desired 3D structure, for example by thermoforming or compression molding, before being bonded to the separator material. For example, techniques similar to those described in relation to steps 805 and 810 (e.g., laser direct structuring process, pad printing process, etc.) may be used to form the second substrate material and define the second conductive region thereon. To bond the second substrate to the separator material, the second substrate may be aligned and bonded to the separator material or at least one of the first substrate material using appropriate adhesive or bonding techniques. Figure 12B shows an example of a 3D tactile sensor formed using this technology.

[0093] Referring to Figure 12B, a diagram 1200B of a 3D tactile sensor formed by fixing a layer of a second substrate material 1210 onto the surface of a substrate material 1202 is shown. The layer of the second substrate material 1210 may be attached following the attachment of a separator material, as shown in Figure 12A. As described herein, the second substrate material 1210 may include conductive regions corresponding to conductive regions 1204 shown in Figure 12A. The conductive regions of the second substrate material 1210 may be positioned such that they are separated by a separator material (e.g., separator material 1208 in Figure 12A) and are arranged to overlap or align with conductive regions 1204 shown in Figure 12A. Any suitable method may be used to bond the second substrate material 1210 to the substrate material 1202, including but not limited to adhesive bonding, thermal lamination, or mechanical fastening. In some implementation configurations, a protective layer (e.g., foam, dielectric material, etc.) may be attached to or bonded to the outer surface of the second substrate material 1210.

[0094] Where used herein in relation to numerical ranges, the terms “approximately,” “about,” “substantially,” and similar terms generally mean + / - 10% of the disclosed value. Where the terms “approximately,” “about,” “substantially,” and similar terms are applied to structural features (e.g., to describe their shape, size, orientation, direction, etc.), these terms are intended to have a broad meaning in harmony with the general and acceptable usage by those skilled in the art to which the subject matter of this disclosure relates, and mean, for example, small variations in the structure that may arise from a manufacturing or assembly process. Accordingly, these terms should be interpreted as indicating that any substantial or insignificant modification or alteration of the subject matter described and claimed is deemed to fall within the scope of the disclosure set forth in the appended claims.

[0095] It should be noted that the term “exemplary” and its variations used herein to describe various embodiments are intended to indicate that such embodiments are examples, representations, or illustrations of possible embodiments (and that such terms are not intended to imply that such embodiments necessarily represent extraordinary or best examples).

[0096] As used herein, the term “coupled” and its derivatives mean joining two members directly or indirectly to one another. Such joining may be fixed (e.g., permanent or fixed) or movable (e.g., removable or detachable). Such joining may be achieved by the two members being directly coupled to one another, by the two members being coupled to one another using separate intervening members and / or additional intermediate members, or by the two members being coupled to one another using an intervening member integrally formed with one of the two members as a single, integrated body. When “coupled” or its derivatives are modified by additional terms (e.g., directly coupled), the general definition of “coupled” given above is modified by the plain language meaning of the additional term (e.g., “directly coupled” means joining two members without separate intervening members) and becomes a narrower definition than the general definition of “coupled” given above. Such joining may be mechanical, electrical, or fluid.

[0097] References to the position of elements in this specification (e.g., “top,” “bottom,” “above,” “below”) are used solely to describe the orientation of various elements in the figures. Note that the orientation of various elements may differ depending on other exemplary embodiments, and such variations are intended to be included in this disclosure.

[0098] Any implementation disclosed herein can be combined with any other implementation, and references such as “one implementation,” “several implementations,” “alternative implementations,” “various implementations,” and “one implementation” are not necessarily mutually exclusive and are intended to indicate that certain features, structures, or characteristics described in relation to an implementation may be included in at least one implementation. Such terms used herein do not necessarily all refer to the same implementation. Any implementation can be combined with any other implementation, comprehensively or exclusively, in any way consistent with the aspects and implementations disclosed herein.

[0099] A reference to "or" may be interpreted as inclusive, such that any term written using "or" may refer to one, two or more, or all of the terms written.

[0100] The drawings and descriptions may illustrate a specific order of method steps, but such order of steps may differ from that illustrated and described unless otherwise specified above. Also, unless otherwise specified above, two or more steps may be performed simultaneously or in partial agreement. Such variations may depend, for example, on the selected software and hardware system and the designer's choice. All such variations are within the scope of this disclosure. Similarly, any software implementation of the described method can be achieved using standard programming techniques having rule-based logic and other logic for achieving various connection steps, processing steps, comparison steps, and decision steps.

[0101] The foregoing description of the disclosed embodiments is provided to enable those skilled in the art to construct or use the embodiments and variations thereof described herein. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the principles defined herein may be applied to other embodiments without departing from the spirit or scope of the subject matter disclosed herein. Accordingly, this disclosure is not intended to be limited to the embodiments shown herein, but should be given the broadest scope consistent with the appended claims and the principles and novel features disclosed herein.

[0102] While various aspects and embodiments are disclosed, other aspects and embodiments are also contemplated. The various aspects and embodiments disclosed are for illustrative purposes only and are not intended to limit, and the true scope and spirit are indicated by the following claims.

Claims

1. A method for forming a three-dimensional (3D) tactile sensor, The steps include preparing a first substrate material for the 3D tactile sensor, The steps include defining a set of first conductive regions for the 3D tactile sensor on the first substrate material, The steps include forming a stacked body by bonding a separator layer between a first substrate material having a set of first conductive regions and a second substrate material having a set of second conductive regions, The steps include forming the aforementioned stacked material into a desired 3D structure, Methods that include...

2. The step of preparing the first substrate material is: Thermoplastic polyurethane, Polyethylene terephthalate, and The method according to claim 1, comprising the step of selecting the first substrate material from the group consisting of polyimide.

3. The step of defining the set of first conductive regions is: The method according to claim 1, comprising the step of arranging a conductive ink on the surface of the first substrate material, wherein the conductive ink forms a set of first conductive regions.

4. The method according to claim 3, further comprising a screen printing process for defining a wiring pattern for the 3D tactile sensor and a step of arranging the conductive ink using a stencil.

5. The step of defining the set of first conductive regions is: The steps include etching channels into the first substrate material corresponding to the wiring pattern for the 3D tactile sensor, The method according to claim 1, comprising the step of providing a conductive material in the channel.

6. The method according to claim 5, wherein the step of etching the channel includes the step of cutting a portion of the first substrate material using a laser.

7. The method according to claim 5, further comprising the step of providing a cover layer on the conductive material, wherein the cover layer exposes at least a portion of the conductive material.

8. The method according to claim 1, further comprising the step of bonding a flexible printed circuit board (PCB) to at least a portion of the set of first conductive regions.

9. The method according to claim 1, wherein the step of forming the stacked material into a target 3D structure includes the step of thermoforming the stacked material using a mold for the target 3D structure.

10. A method for forming a three-dimensional (3D) tactile sensor, The steps include forming a first substrate material according to the desired 3D structure for the 3D tactile sensor, The steps include defining a set of first conductive regions for the 3D tactile sensor on the first substrate material, The steps include providing a separator material on at least a portion of the set of first conductive regions, A step of bonding a second substrate material having a set of second conductive regions to the separator material, wherein the second substrate material conforms to the 3D structure of the first substrate material. Methods that include...

11. The step of forming the first substrate material according to the aforementioned target 3D structure is: The method according to claim 10, comprising the step of thermoforming a layer of the first substrate material using a mold corresponding to the target 3D structure of the 3D tactile sensor.

12. The step of defining the set of first conductive regions is: The method according to claim 10, comprising the step of depositing one or more conductive wirings onto the surface of the first substrate material using a 3D distribution process.

13. The step of defining the set of first conductive regions is: The steps include defining one or more activation regions on the surface of the first substrate material, The method according to claim 10, comprising the step of plating one or more of the activated regions with a conductive material.

14. The method according to claim 13, further comprising the step of defining one or more activation regions using a laser according to a wiring pattern for the 3D tactile sensor.

15. The step of defining the set of first conductive regions is: The method according to claim 10, further comprising the step of providing one or more conductive wirings on the surface of the first substrate material using a pad printing process.

16. The step of providing the separator material is: The method according to claim 10, comprising the step of attaching the separator material to a portion of the set of first conductive regions using a 3D distribution process.

17. The step of providing the separator material is: The method according to claim 10, comprising the step of bonding a layer of dielectric material to the first substrate material to cover the set of first conductive regions.

18. The method according to claim 10, further comprising the step of attaching one of the first substrate material or the second substrate material to a support material.

19. A three-dimensional (3D) tactile sensor, The stacked body comprises, A first layer of a substrate material having a set of first conductive regions, A separator material bonded to the first layer of the substrate material, The substrate material comprises a second layer having a set of second conductive regions separated from the set of first conductive regions by the separator material, A three-dimensional (3D) tactile sensor in which the stacked body is thermoformed to conform to the desired 3D structure.

20. The 3D tactile sensor according to claim 19, wherein the separator material includes one of a dielectric material or a piezoresistive material.

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