Multi-level tactile feedback transducer and tactile feedback interface Multi-level tactile feedback transducer

Abstract

The present invention relates to a multi-level tactile feedback transducer and a tactile feedback interface multi-level tactile feedback transducer. One aspect relates to a tactile feedback transducer comprising an electroactive material (EAM) film arranged on a substrate, wherein the EAM film comprises an EAM layer configured to provide a mechanical response in response to an electrical drive signal. The tactile feedback transducer also includes an air pump configured to control the pressure of a gas applied to a side of the EAM film facing the substrate. In addition, a tactile feedback interface comprising one or two or more tactile feedback transducers is provided, and wherein the substrate is common to each tactile feedback transducer. In addition, a tactile feedback interface comprising an electrical drive circuit for driving a tactile feedback transducer is provided, wherein the electrical drive circuit is configured to: provide a first EAM electrical drive signal to the EAM layer, and / or provide a first air pump electrical drive signal to the air pump.

Description

Technical Field

[0001] The present disclosure relates to a multi-level tactile feedback transducer and a multi-level tactile feedback transducer for a tactile feedback interface. The present invention also relates to a multi-level tactile feedback interface including an electrical drive circuit. Background Art

[0002] Haptic applications are growing for handheld touch-sensitive interfaces (such as consumer electronics) and customizable dashboards and screens for automotive applications. Haptic feedback recreates the sense of touch in user interface devices by transmitting mechanical force, pressure, or vibration to convey information to the user. In particular, haptic actuators are the main components of the haptic system that provide mechanical actuation to transmit tactile sensations to the user.

[0003] Today's haptic touch interfaces are primarily characterized by vibrotactile feedback driven by inertial-type actuators, such as eccentric rotating mass (ERM) and linear resonant actuators (LRA). These actuators have individual limitations, particularly large size, lack of real feedback, and complex mechanical design. These actuators also do not provide the static forces or deformations required for handheld touch interfaces. Piezoelectric ceramic-based actuators based on vibrotactile feedback are also used in consumer electronics. However, the lack of physically large strain responses and real tactile feedback in these actuators limits the further deployment of such actuators in handheld touch-sensitive interfaces.

[0004] Therefore, there is a need for improved haptic actuators, and in particular, a need for haptic actuators with multi-level haptic feedback modulation. Summary of the invention

[0005] It is therefore an object of the present invention to provide an improved multi-level tactile feedback transducer.It is a further object of the present invention to provide a tactile feedback interface comprising a multi-level tactile feedback transducer.

[0006] A plurality of embodiments may provide a tactile feedback transducer. The tactile feedback transducer may include an electroactive material (EAM) film that may be arranged on a substrate. The EAM film may include an EAM layer that may be configured to provide a mechanical response in response to an electrical drive signal. The tactile feedback transducer may also include an air pump that may be configured to control the pressure of a gas. The air pump may be configured to apply the pressure of the gas to a side of the EAM film that may face the substrate.

[0007] Various embodiments may provide a tactile feedback interface that may include one tactile feedback transducer, or two or more tactile feedback transducers.The tactile feedback transducers on the tactile feedback interface may share a common substrate.

[0008] Various embodiments may provide a tactile feedback interface that may include an electrical drive circuit. The electrical drive circuit may be configured to drive the tactile feedback transducer and may provide a first EAM electrical drive signal to the EAM layer. The electrical drive circuit may also be configured to provide a first air pump electrical drive signal to the air pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The invention will be better understood with reference to the detailed description when considered in conjunction with the non-limiting examples and accompanying drawings, in which:

[0010] Figure 1 Schematic diagram of a tactile feedback transducer 10 according to various embodiments is shown, the tactile feedback transducer 10 comprising an air pump 14, an EAM membrane 11 comprising an EAM layer 12 disposed on a substrate 13, and an elastic cover layer 18 disposed on the EAM membrane 11;

[0011] Figure 2A and Figure 2B A schematic diagram showing the working mechanism of the tactile feedback transducer 10 according to multiple embodiments;

[0012] Figure 3 shows a schematic diagram of a tactile feedback transducer 30 according to various embodiments, wherein the air pump 14 includes a stack of micro-blowers 16;

[0013] Figure 4 Schematic diagram of a tactile feedback transducer 40 according to various embodiments is shown, the tactile feedback transducer 40 further comprising a center piece 17 stacked on the EAM layer 12;

[0014] Figure 5A and Figure 5B A schematic diagram showing the working mechanism of the tactile feedback transducer 40 according to multiple embodiments;

[0015] Figure 6 A schematic diagram showing a top view of the EAM layer 12 of the tactile feedback transducer 10 according to various embodiments;

[0016] Fig. 7A and Figure 7B Schematic diagrams showing a top view and a cross-sectional view of the EAM layer 12 of the tactile feedback transducer 10 according to various embodiments, wherein the EAM layer 12 includes a slit 72 provided as a through opening or a recessed portion 73 in a concave configuration along a direction perpendicular to the top surface of the EAM layer 12;

[0017] Fig. 8A A schematic diagram showing a cross-sectional view of the EAM layer 12 of the tactile feedback transducer 10 according to various embodiments, wherein the thickness of the EAM layer 12 decreases from the outer portion of the EAM layer 64 to the inner portion of the EAM layer 65;

[0018] Figure 8B A schematic diagram showing a top view of the EAM layer 12 of the tactile feedback transducer 10 further comprising an open window 81 according to various embodiments;

[0019] Fig.9A and Fig. 9B shows a schematic diagram of a tactile feedback transducer 10 according to various embodiments, wherein an EAM layer 12 is mechanically attached to a substrate 13 by a fastener 90;

[0020] Fig.10 Schematic diagram of a tactile feedback interface 100 according to various embodiments is shown, the tactile feedback interface 100 further comprising a plurality of tactile feedback transducers 10;

[0021] Fig.11 1 shows a schematic diagram of a tactile feedback interface 110 according to various embodiments, the tactile feedback interface 110 further comprising an air channel 112, a valve 113, and one or more additional tactile feedback transducers 111 without an air pump;

[0022] Fig. 12A shows a graph illustrating the force generated from the air pump 14 without actuation of the EAM layer 12 according to various embodiments;

[0023] Fig. 12B shows a graph illustrating the force generated from the air pump 14 in conjunction with actuation of the EAM layer 12 according to various embodiments; and

[0024] Fig.13 A graph is shown illustrating various multi-level feedback forces generated by the air pump 14 and / or the EAM layer 12 according to various embodiments. DETAILED DESCRIPTION

[0025] The following detailed description refers to the accompanying drawings, which show by way of illustration specific details and embodiments in which the present disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the present disclosure. Other embodiments may be utilized, and structural and logical changes may be made without departing from the scope of the present disclosure. Multiple embodiments need not be mutually exclusive, as some embodiments may be combined with one or more other embodiments to form new embodiments.

[0026] A feature described in the context of one embodiment may be applicable to the same or similar features in other embodiments accordingly. Features described in the context of one embodiment may be applicable to other embodiments accordingly even if not explicitly described in these other embodiments. In addition, additions and / or combinations and / or substitutions described for a feature in the context of one embodiment may be applicable to the same or similar features in other embodiments accordingly.

[0027] The disclosure described illustratively herein can be appropriately practiced in the absence of any one or more elements, one or more limitations not specifically disclosed herein. Therefore, for example, the terms "including", "comprising", etc. should be understood broadly and without restriction. The expression "including" will therefore be understood to imply the inclusion of the stated whole or groups of wholes, but does not exclude any other whole or groups of wholes. In addition, the terms and expressions adopted herein have been used as terms of description rather than limitation, and it is not intended to use such terms and expressions to exclude any equivalent form of the features shown and described or parts thereof, but it should be recognized that various modifications can be made within the scope of the present disclosure. Therefore, it should be understood that although the present disclosure has been specifically disclosed by exemplary embodiments and optional features, those skilled in the art can modify and change the present disclosure embodied herein.

[0028] In the context of multiple embodiments, the quantifiers "a", "an" and "the" used with respect to a feature or element include reference to one or more features or elements. As used herein, the term "and / or" includes any and all combinations of one or more associated listed items.

[0029] Reference numerals included in parentheses in the claims are for easy understanding of the present invention and have no limiting effect on the scope of the claims.

[0030] According to various embodiments, the term "electroactive material (EAM) film" may refer to a film that can provide a mechanical response in response to an applied electric field. The EAM film may include an EAM layer, such as an electroactive polymer (EAP), for example an ionic EAP (iEAP) layer. In the context of the present disclosure and according to various embodiments, the EAM layer may include an iEAP that can provide a mechanical response in response to an applied electrical drive signal.

[0031] According to various embodiments, when describing an element, such as a segment, comprising an EAM layer, the term "mechanical response" may refer to, for example, a displacement force, which may include bending, a change in at least one dimension (such as length), a volume change, a conformational change, or a combination thereof. For example, the mechanical response of one of the multiple segments may represent that the segment displaces or bends to one side.

[0032] According to a number of embodiments, the term "air pump" may refer to a pump that is used to compress air to generate a pressure difference between the two sides of the pump, such as generating a net positive pressure on one side of the pump. For example, the air pump may include at least one micro-blower, and may be configured to drive an airflow and thereby control the pressure of the gas applied to another device. As another example, the air pump may provide a static pressure of the gas to the EAM membrane. In the context of the present disclosure and according to a number of embodiments, the air pump may be configured to control the pressure of the gas applied to the side of the EAM membrane facing the substrate.

[0033] According to a number of embodiments, the term "pressure of a gas" may refer to a force per unit area applied perpendicular to the surface of an object, which is distributed on the surface. For example, the pressure of a gas may be applied by a gas flow applied to any surface in contact with the gas. In the context of the present disclosure and according to a number of embodiments, the application of the pressure of a gas may include applying a gas flow to one side of the EAM film facing the substrate. Since the film is at least partially movable and / or at least partially elastically deformable, the film may extend and / or move according to a displacement force, which is a net force caused by a pressure difference on both sides of the film.

[0034] Figure 1 A schematic diagram of a tactile feedback transducer 10 according to multiple embodiments is provided. The tactile feedback transducer 10 may include a substrate 13. The tactile feedback transducer 10 may include an EAM membrane 11 disposed on the substrate 13. The EAM membrane 11 includes an EAM layer 12 configured to provide a mechanical response in response to an electrical drive signal. For example, the EAM membrane 11 may include a segment of the EAM layer 12 disposed on the substrate 13. The tactile feedback transducer 10 may also include an air pump 14. The substrate 13 may be disposed between the EAM membrane 11 and the air pump 14, so that the air pump 14 may be configured to control the pressure of a gas 15 applied to a side of the EAM membrane 11 that may face the substrate 13.

[0035] According to various embodiments, the tactile feedback transducer 10 may further include an elastic cover layer 18 that may be disposed on the EAM membrane 11. The elastic cover layer 18 may be provided as a separate layer. For example, the elastic cover layer 18 may be disconnected from the EAM membrane 11. The elastic cover layer 18 may encapsulate and seal the tactile feedback transducer 10. For example, the elastic cover layer 18 may seal the pressure of the gas 15 applied to the EAM membrane 11.

[0036] According to various embodiments, the elastic cover layer 18 may include an elastic material. The elastic cover layer 18 may include or consist of a thin elastic layer, such as a double-sided acrylic foam tape or an acrylic elastomer. An example of a double-sided acrylic foam tape may be 3M TM VHB TM (very high adhesion) film. Examples of acrylic elastomers can be 3MTM VHB TM As another example, the elastic cover layer 18 may include or comprise a silicone rubber film such as a polydimethylsiloxane (PDMS) film, or a Cross-linked silicone rubber of the membrane. According to various embodiments, the elastic cover layer 18 may exhibit an elastic modulus between 0.1 MPa and 10 MPa.

[0037] According to various embodiments, the EAM film 11 may further include other components. For example, the EAM film 11 may include components such as electrodes disposed on the EAM film 11 .

[0038] According to multiple embodiments, the EAM layer 12 may include an electroactive polymer (EAP), for example, an iEAP, which can be used to generate large bending deformations at low driving voltages (such as 5V or lower). EAP-based actuators have been used as tactile actuators for handheld touch-sensitive interfaces. Examples of EAPs may include: ferroelectric electroactive polymers, conductive polymers, and iEAPs. There are still some limitations to the use of ferroelectric electroactive polymers or conductive polymers in these actuators, because such actuators are more useful for vibration tactile feedback rather than for static deformation applications, which are required for handheld touch-sensitive interfaces. iEAP is a subclass of EAP and can be used to generate larger bending deformations at low driving voltages, and is therefore a good soft actuator technology, particularly suitable for next-generation surface-covered tactile actuator applications. The advantages of iEAP include low-voltage drive mechanisms, large bendable actuation deformations, and out-of-plane (protruding) deformations. However, there are still some performance issues with using iEAPs in conventional actuators, such as small displacement, slow response time, poor material properties, poor durability, high power consumption, and low holding and actuation forces due to high post-relaxation problems, resulting in a lack of perceptible tactile feedback force. For example, some iEAP actuators for generating large holding forces require continuous power, resulting in high power consumption. Thus, for surface-covered tactile applications that require large protruding deformation motions and surface frequency modulation, such as shape-retaining touch button interfaces with multi-level surface frequency modulation, the use of iEAPs in conventional actuators has not yet been fully realized.

[0039] like Figure 1 The tactile feedback transducer 10 shown is provided for illustrative purposes, and the present disclosure is not limited thereto. The tactile feedback transducer may also include a channel between the substrate and the EAM membrane. Alternatively or additionally, the tactile transducer may include a channel integrated into the substrate and may be placed between the substrate and the EAM membrane. The channel may provide a channel for air to flow along it. For example, the channel may direct the pressure of the gas from the air pump to the EAM membrane. The tactile feedback transducer may also include a housing module to seal the individual components of the tactile feedback transducer.

[0040] Figure 2A and 2B Schematic diagram showing the working mechanism of the tactile feedback transducer 10. The tactile feedback transducer 10 may include a first configuration (eg Figure 2A As shown), the second configuration (as Figure 2B As shown) and other optional configurations. For example, in the first configuration, as Figure 2A As shown, even when the air pump 14 is turned off, the tactile feedback transducer 10 can generate a first displacement force in response to the electric drive signal provided to the EAM film 11. For example, when the electric drive signal of the first voltage is applied, the horizontal height and / or shape can be changed by actuation of the EAM film 12. In another example, a mechanical periodic protruding deformation motion can be generated, wherein optionally, the periodic protruding deformation motion can be controlled, for example, using an electric drive signal including a first frequency. The electric drive signal can be further modulated. Alternatively and according to multiple embodiments, the tactile feedback transducer 10 can have a configuration in which the displacement force generated by the tactile feedback transducer 10 responds to the pressure of the gas 15 applied by the air pump 14. For example, the electric drive signal may not be provided to the EAM film 11, so that the tactile feedback transducer 10 only receives the static pressure of the gas from the air pump 14. Therefore, a steady-state holding force can be generated by the tactile feedback transducer 10. In addition, the elastic cover layer 18 can be elastically deformed when the pressure of the gas 15 is applied to the EAM film 11. For example, the elastic cover layer 18 may seal the pressure of the gas 15 applied to the EAM membrane 11 .

[0041] Figure 2B A schematic diagram of a second displacement force generated in a second configuration according to various embodiments is provided. Figure 2BAs shown, when the air pump 14 can be turned on to provide the pressure of the gas 15 to the EAM film 11, the second displacement force can be generated in response to the electrical drive signal applied to the EAM film 11. For example, the electrical drive signal applied to the EAM film 11 can be synchronized with the pressure of the gas 15 provided by the air pump 14. As a result, the tactile feedback transducer 10 can generate a second displacement force greater than the first displacement force. For example, the second displacement force can be a greater actuation and retention force than the first displacement force. As another example, the second displacement force can be greater than the displacement force generated when only the air pump 14 is in operation. In other words, due to the actuation of the EAM film 11 and the air pump 14, the second displacement force generated by the tactile feedback transducer 10 can be an improved displacement force with a large deformation. The second displacement force can be substantially equal to the sum of the displacement force generated when only the air pump 14 is in operation and the first displacement force generated when the electrical drive signal is only applied to the EAM film 11. For example, the second displacement force may be beneficial because it can provide an enhanced tactile perception to a user operating the tactile feedback transducer. As another example, the second displacement force may be a realistic and perceptible tactile feedback force provided to the user.

[0042] Figure 3 A schematic diagram of a tactile feedback transducer 30 according to multiple embodiments is shown. The tactile feedback transducer 30 may include an air pump 14, which also includes at least one micro-blower 16. For example, the air pump 14 may include a plurality of micro-blowers 16, such as a stack of micro-blowers 16. As another example, the air pump 14 may include a stack of three micro-blowers 16, which are stacked (on top of each other) in a series connection. The micro-blower 16 in the air pump 14 can provide the pressure of the gas 15 (e.g., the static pressure of the gas 15) to the EAM film 11. Depending on the user's preference, the following properties of the air pump 14 can be adjusted by configuring the design parameters: the number of micro-blowers and the type of series connection of the micro-blowers. The design parameters of the micro-blower 16 in the air pump 14 can also be adjusted, for example, one or more of the maximum voltage, maximum flow rate, maximum pressure, and size can be selected according to the needs of the application. In this way, the resulting displacement and holding force can be easily adjusted. For example, a greater displacement force may be generated by increasing the number of micro-blowers 16 in the air pump 14. As another example, a greater displacement force may be generated by increasing the maximum voltage, flow rate, and / or pressure provided to the micro-blower 16.

[0043] According to multiple embodiments, the micro-blower may include a piezoelectric motor based on the change in shape of a piezoelectric material when an electric field is applied. For example, the micro-blower can be designed as a blower by applying ultrasonic vibrations of a piezoelectric material as a driving source. As another example, the micro-blower may include a piezoelectric micro-blower. The piezoelectric micro-blower can be thin, compact, lightweight and quiet, and can provide a high air flow rate. In addition, the piezoelectric micro-blower can be easily mounted to a tactile feedback transducer, for example, to a substrate.

[0044] Figure 4 Schematic diagrams of tactile feedback transducers 40 according to various embodiments are shown. The tactile feedback transducer 40 may also include a center piece 17 superimposed on the EAM membrane 11 including the EAM layer 12. For example, the center piece 17 may partially cover a portion of the EAM layer 12 and may partially cover a portion of the EAM membrane 11. The center piece 17 may be configured to be deformable upon actuation of the EAM membrane 11 and / or application of pressure of the gas 15 provided by the gas pump 14 (e.g., the static pressure of the gas).

[0045] Figure 5A and 5B FIG. 4 is a schematic diagram showing the working mechanism of the tactile feedback transducer 40 according to multiple embodiments. The tactile feedback transducer 40 may include a first configuration (eg Figure 5A As shown), the second configuration (as Figure 5B As shown) and other optional configurations. For example, in the first configuration, as Figure 5A As shown, the center piece 17 has a first height, so that the center piece 17 is in a first position relative to the EAM layer 12. According to various embodiments and in the context of the present disclosure, the term "height" may refer to the height difference between a portion closer to the substrate (proximal end) and a portion farther from the substrate (distal end). For example, an electrical drive signal may be applied to the EAM membrane 11, and the air pump 14 may not be operated in the first configuration. Therefore, the center piece 17 may be in the first position only due to the actuation of the EAM membrane 11. As shown in FIG. Figure 5B As shown, in the second configuration, the center piece 17 can protrude above the EAM layer 12 so that the center piece has a second height and can be in a second position relative to the EAM layer 12. The second height at the second position can be greater than the first height of the center piece 17 in the first position. For example, the second configuration can be a configuration that causes a large protruding deformation movement of the EAM layer 12 and the center piece 17, which can be responsive to the actuation of the EAM membrane 11 and the operation of the air pump 14. As another example, the center piece 17 can play an important role in allowing the deformation movement to produce sharp edge deformations.

[0046] According to various embodiments, the center piece may include a lightweight hard material. The center piece may include a lightweight preformed layer having non-elastic properties. For example, the center piece may include or include a plastic layer having a thickness in the range of 0.5 mm to 1.0 mm, an elastic modulus greater than 2 GPa, and less than 1.5 g / cm 3 As another example, the center piece may include materials such as polymethyl methacrylate, polycarbonate, polyethylene terephthalate, and acrylic sheet. The center piece may be at least partially superimposed on the EAM film. The center piece may be used as a passive layer for vertical movement and thus may achieve mechanical deformation with sharp edges. For example, the sharp edge deformation may include a second configuration in which the center piece 17 protrudes above the EAM layer 12 so that the center piece is at a second height and a second position relative to the EAM layer 12. The second height may be greater than the first height. The sharp edge may be conceptually proven by the vertical movement of the center piece, which is caused by the deformation movement of the actuating section below the EAM layer. This sharp edge deformation is beneficial because it further enhances the tactile perception of the user operating the tactile feedback transducer.

[0047] Figure 6 Schematic diagrams showing a top view of an EAM layer 12 according to various embodiments. For illustrative purposes, the top view may be compared to Figure 1 The top view of the EAM layer 12 of the tactile feedback transducer 10 is the same. The EAM layer 12 may include a center 62, and a plurality of radial cuts 61 may extend radially from the center 62. The portion between two adjacent cuts may define a plurality of segments 63. For example, the segment 63 may be petal-shaped and may include the EAM layer 12. Figure 6 In the embodiment, only one of the plurality of cutouts and the plurality of segments is indicated by a reference numeral, but it should be understood that the term "plurality" within the meaning of various embodiments may represent 2 or more, such as all cutouts and / or all segments. According to various embodiments, a segment 63 of the plurality of segments may also include: a first portion 64, such as an end far from (outside) the center 62; and a second portion 65, such as an end close to (inside) the center 62. In the context of the present invention, the segment 63 of the EAM layer 12 may be referred to as an EAM cantilever beam.

[0048] According to various embodiments, the term "cut" may refer to a break in an EAM layer. For example, a break or discontinuity may be provided within the EAM layer such that the portion between two adjacent breaks may define a segment. In the context of the present disclosure and according to various embodiments, the term "cut" refers to an open EAM layer and is not limited to an opening provided by cutting an EAM layer.

[0049] Fig. 7ASchematic diagrams of EAM layer 12 according to multiple embodiments are shown. The left view is a top view of EAM layer 12. The upper right view 70 is a top view of segment 63, and the lower right view is a cross-sectional view of segment AA' through segment 63. With reference to the upper right view 70 and the lower right view, segment 63 may include a plurality of slits 72. For example, a plurality of slits 72 may be arranged and extend from a first portion 64 of segment 63 to a second portion 65 of segment 63. As another example, slits 72 may form a through opening through the thickness direction of EAM layer 12. The through opening may be elongated. In some embodiments, the through opening may be limited to within segment 63.

[0050] According to various embodiments, the term "thickness" may refer to the distance between two opposite sides of an EAM layer. In the context of the present disclosure and according to various embodiments, the thickness of an EAM layer may include the distance from the top surface to the bottom surface of the EAM layer.

[0051] Figure 7B Schematic diagrams of an EAM layer 12 according to various embodiments are shown. The left view is a top view of the EAM layer 12. The upper right view 71 is a top view of the segment 63, and the lower right view is a cross-sectional view of a portion BB' through the segment 63. Referring to the upper right view 71 and the lower right view, the segment 63 may include a plurality of recesses 73. For example, the plurality of recesses 73 may be arranged and extend from a first portion 64 of the segment 63 to a second portion 65 of the segment 63. For example, the recesses 73 may form recesses or depressions through the thickness of the EAM layer 12, and may be cut or opened in a manner that does not pass through the entire thickness of the EAM layer 12. As another example, the recesses 73 may be partially cut through the thickness of the EAM layer 12.

[0052] According to various embodiments, the orientation, size (width, length), number, and position of the plurality of slits and / or the plurality of recesses may affect the actuation performance of the improved tactile feedback transducer. For example, the slits and / or recesses may be in an arcuate configuration or a radial configuration. For example, in an arcuate configuration, the slits and / or recesses may form an arc with a common concentric center, wherein the common center may be at the center of the EAM layer. Alternatively, in a radial configuration, the slits and / or recesses may be radial segments with a radius originating from the center of the actuator.

[0053] Fig. 8A Schematic diagrams of EAM layer 12 according to various embodiments are shown. The left view is a top view of the EAM layer, and the right view 80 is a cross-sectional view of section CC' through segment 63. The thickness of segment 63 can decrease from first portion 64 to second portion 65. For example, the EAM layer 12 at the first (outer) portion 64 can be thicker than the EAM layer 12 at the second (inner) portion 65. In the context of the present disclosure, according to Fig. 8AThe section 63 may be referred to as having an elongated beam configuration.

[0054] According to various embodiments, segments including multiple slits, recesses, and / or reduced thickness of the EAM layer may help reduce the bending stiffness of the EAM cantilever structure, resulting in greater displacement force and faster actuation response of an improved haptic feedback transducer.

[0055] Figure 8B Schematic diagrams of EAM layer 12 according to various embodiments are shown. The left view is a top view of EAM layer 12, and the right view 82 is a top view of segment 63. Segment 63 may include an open window 81. For example, an opening or space may be provided through the thickness of segment 63. The open window 81 may provide a partial opening on segment 63. For example, the open window 81 may occupy a portion of the total surface area of ​​segment 63.

[0056] According to various embodiments, the open windows allow protrusions to be formed within the segments and allow for better modulated surface motion (surface frequency modulation) to be generated. For example, a tactile feedback transducer including an open window on the EAM layer can provide a larger and more perceptible displacement and thus can enhance the tactile perception of a user operating the tactile feedback transducer.

[0057] Fig.9A and 9B A schematic diagram of an EAM layer 12 that can be mechanically attached to a substrate 13 by a fastener 90 is shown. For illustrative purposes, the left view is a top view of the EAM layer 12. The right views 91 and 93 are cross-sectional views of the D-D' and E-E' sections through the first (outer) portion 64 of the segment 63. The segment of the EAM layer 12 can be mechanically attached to an underlying substrate 13 (not shown) by the fastener 90.

[0058] According to a number of embodiments, a fastener may include a device for mechanically joining and / or fixing two or more objects. The fastening mechanism may be permanent, and the fastener may be used to create an immovable joint. For example, a fastener may include a device for mechanically joining or fixing an EAM layer to a substrate. As another example, a fastener may include a concave or convex clamping part. For example, a concave or convex EAM cantilever beam may be provided by utilizing a concave or convex clamping part to generate a larger, more stable and repeatable displacement motion as a result of the bistable motion of the curved EAM cantilever structure, compared to an EAM cantilever beam without a fastener.

[0059] refer to Fig.9A, the fastener may include a preformed clamping device, such as a simple support. The simple support may include a pin or roller support 92, which may include fasteners such as screws and / or rivets to mechanically clamp the EAM layer 12 to the substrate 13. Alternatively and with reference to Fig. 9B , the fastener may include a portion of the clamp. For example, the portion of the clamp may include a wave spring 94 that may be embedded within the clamp. For example, the wave spring 94 may be superior to conventional coil springs because they provide a lower action height with the same force, thereby providing a smaller component that uses less material and results in a lower production cost. In addition, the use of the wave spring 94 may provide a stronger displacement force and enhance the tactile sensation provided to the user. For example, the wave spring 94 may reduce the contact area of ​​the clamping area. As a result, the EAM cantilever beam including the wave spring 94 may produce an improved deformation motion with a greater degree of freedom of deformation motion, even at low drive voltages.

[0060] According to various embodiments, the term "multiple tactile feedback transducers" may represent two or more tactile feedback transducers. For example, a tactile feedback interface may include three, four, or five or more tactile feedback transducers. In the context of the present disclosure and according to various embodiments, the term "multiple" defines two or more tactile feedback transducers.

[0061] Fig.10 A schematic diagram of a tactile feedback interface 100 according to multiple embodiments is shown. The tactile feedback interface 100 may include one or more tactile feedback transducers 10. For example, the tactile feedback interface 100 may include one tactile feedback transducer 10, or two or more tactile feedback transducers 10. Multiple tactile feedback transducers 10 may be arranged according to a predefined pattern (e.g., a matrix structure). Multiple tactile feedback transducers 10 may be arranged on a common substrate 130. For example, multiple tactile feedback transducers 10 may share a common substrate 130. The tactile feedback interface 100 may be a touch-sensitive interface, such as a keyboard, a keypad, a portion of a touch screen, or a portion of a display. The tactile feedback interface 100 may include a multi-level button array, and each button of the array includes a tactile feedback transducer according to multiple embodiments of the present disclosure. One or more feedback transducers 10 may be located, for example, above or below a display layer.

[0062] According to various embodiments, a tactile feedback interface including one or more tactile feedback transducers can be electrically coupled to an electrical drive circuit such that an electrical drive signal can be applied to each tactile feedback transducer independently or to the plurality of tactile feedback transducers as a whole through the electrical drive circuit. For example, the electrical drive circuit can provide an EAM electrical drive signal to the EAM layer. As another example, the electrical drive circuit can provide an air pump electrical drive signal to an air pump (e.g., a micro-blower within the air pump).

[0063] Fig.11 Schematic diagram of a tactile feedback interface 110 according to various embodiments is shown. The tactile feedback interface 110 may include one or more tactile feedback transducers 10 according to various embodiments of the present disclosure. In addition, the tactile feedback interface 110 may include one or more tactile feedback transducers 111 without air pumps. For example, the tactile feedback transducers 111 without air pumps may not include individual air pumps within the tactile feedback transducers (compare Figure 1 , Figure 1 A diagram of a tactile feedback transducer with an air pump 14 is provided). The tactile feedback transducer 111 without an air pump may include an EAM film disposed on a common substrate 130. The tactile feedback interface 110 may also include one or more air channels 112. The air channels 112 may provide a connection between at least one tactile feedback transducer 10 and at least one tactile feedback transducer 111 without an air pump. For example, the air channels 112 may provide a channel for transmitting gas pressure from the air pump of at least one tactile feedback transducer 10 to at least one tactile feedback transducer 111 without an air pump.

[0064] According to various embodiments, the air channel 112 may further include a valve 113 or multiple valves 113. For example, the valve 113 may include a device for directing or controlling the air flow through the air channel 112 by opening, closing, or partially blocking the air channel 112. For example, the valve 113 may be in an open configuration to allow the pressure of the gas to flow from the air pump of at least one tactile feedback transducer 10 to at least one tactile feedback transducer 111 without an air pump. Alternatively or additionally, the valve 113 may be in a closed or partially blocked configuration to reduce or block the pressure of the gas from the air pump of at least one tactile feedback transducer 10 to at least one tactile feedback transducer 111 without an air pump. The valve 113 may be configured to control the pressure of the gas provided to one or more (e.g., each) tactile feedback transducer 111 without an air pump. As a result, the number of air pumps required in the tactile feedback interface 110 may be reduced, thereby reducing power consumption.

[0065] According to various embodiments, a tactile feedback transducer may be a multi-level tactile feedback transducer. A tactile feedback interface including one or more tactile feedback transducers may be a multi-level tactile feedback interface.

[0066] Fig. 12AA graph 120 is shown according to multiple embodiments, which shows the relationship between the force generated by the tactile feedback transducer 10 and the time signal 121 in the absence of actuation of the EAM membrane. For example, the graph 120 may show the displacement force generated by the tactile feedback transducer 10 when the air pump is operating. The air pump in operation may represent that the air pump is controlled by an air pump electrical drive signal provided to the air pump. The signal 121 may include a first state A (represented by time frame "A") and a second state B (represented by time frame "B"). The first state A may be a state when the air pump can be turned off, and therefore, the tactile feedback transducer may not generate force. The second state B may be a state where the air pump can be turned on to provide gas pressure to the EAM membrane. For example, the air pump can control the static pressure of the gas applied to the side of the EAM membrane facing the substrate. As Fig. 12A As shown, 1.5×10 -2 In other words, when the air pump is operating and when no electric drive signal is applied to the EAM film, the tactile feedback transducer 10 can generate a steady-state holding force of 1.5×10 -2 N steady-state force.

[0067] Fig. 12B Graph 122 is shown, which shows the relationship between the force generated by the actuation of the EAM membrane 123 and the time signal (represented by the dashed line), and the relationship between the force generated by the actuation of the EAM membrane and the operation of the air pump 124 and the time signal (represented by the solid line). Signal 123 shows that the displacement force generated by the tactile feedback transducer 10 (only the EAM membrane 12) can be periodic, with a maximum displacement force of 0.5×10 -2 N. Signal 124 shows that the displacement force generated by the tactile feedback transducer 10 (actuation of the EAM film 12 in combination with the air pump 14) can be increased four times to a maximum of 2.0×10 -2 N. The displacement force generated (as shown by signal 124) may include two feedback levels, namely, 1.5×10 -2 Static protrusion deformation force (N) Fig. 12A The signal in 121) and 1.0×10 -2 N peak-to-peak modulation ( Fig. 12B123 in FIG. 1 ), thereby achieving two feedback levels, as shown by signal 124. The tactile feedback transducer 10 can be used as a multi-level tactile feedback transducer because the user can adjust the displacement force generated by the tactile feedback transducer 10 by modulating the EAM electrical drive signal and / or adjusting the driving parameters of the air pump electrical drive signal (e.g., by adjusting the driving frequency, voltage, and waveform). For example, the user can increase the initial displacement force generated by the tactile feedback transducer 10 by increasing the driving voltage of the air pump electrical drive signal and / or increasing the driving voltage of the EAM electrical drive signal, thereby increasing the resulting displacement force generated by the tactile feedback transducer 10.

[0068] According to a plurality of embodiments, the displacement force generated by the tactile feedback transducer 10 may be caused by the actuation of one or more sections of the EAM film. For example, the displacement force may be in response to an electrical drive signal applied to the EAM film. By controlling the driving parameters of the electrical drive signal applied to the EAM film, the tactile feedback transducer 10 may generate various displacement forces. For example, the electrical drive signal applied to the EAM film may be modulated based on the driving voltage, waveform or frequency of the EAM electrical drive signal. Alternatively and additionally, the displacement force generated by the tactile feedback transducer 10 may also be caused by the operation of one or more micro-blowers of the air pump, which provide the pressure of the gas applied to one side of the EAM film. By controlling the driving parameters of one or more micro-blowers, the tactile feedback transducer 10 may generate various displacement forces. For example, the tactile feedback transducer 10 may generate various deformation levels. Since the user can modulate the electrical drive signal applied to the EAM film and / or adjust the driving parameters of the micro-blowers, the deformation level generated by the tactile feedback transducer 10 may be controllable.

[0069] Fig.13A graph 132 is shown, which illustrates various multi-level feedback forces that can be generated by the tactile feedback transducer. For example, various displacement forces can be generated by adjusting the driving parameters of the air pump electric drive signal applied to the air pump and by modulating the electric drive signal applied to the EAM film. For the purpose of illustration, the graph 132 can be the relationship between the force and the time signal sampled at different time points. For example, when the micro-blower can be turned on and no EAM electric drive signal is applied to the EAM film, the time point "A" can represent the first event. The tactile feedback transducer 10 can generate a steady-state holding force only due to the operation of the micro-blower. For example, when the micro-blower can be turned off and no EAM electric drive signal is applied to the EAM film, the time point "B" can represent the second event. As a result, the tactile feedback transducer 10 may not generate a displacement force. For example, when the electric drive circuit is configured to provide a first air pump electric drive signal to the air pump and provide a first EAM electric drive signal to the EAM film, the time point "C" can represent the third event. A first displacement force that is periodic in nature and has a first frequency and amplitude level can be generated. When the micro-blower is turned off and no EAM electrical drive signal is provided to the EAM film, therefore, the tactile feedback transducer 10 may not generate force, and time point "D" may represent a fourth event (similar to time point "B", the second event). For example, when the user provides the first air pump electrical drive signal to the air pump, time point "E" may represent a fifth event. The first air pump electrical drive signal may be the same as the signal applied during time point "C". The second EAM electrical drive signal may be applied to the EAM film. A second displacement force that is periodic in nature and has a second frequency and amplitude level can be generated. The second displacement force may be less than the first displacement force. For example, the second frequency and amplitude level may be lower than the first frequency and amplitude level (during time point "C"). For example, the user may modulate the EAM electrical drive signal applied to the EAM film. For example, when the user turns off the micro-blower but continues to provide the EAM electrical drive signal to the EAM film, time point "F" may represent a sixth event. When the micro-blower is not operating, the displacement force generated by the tactile feedback transducer 10 can be significantly reduced. For example, when the user provides a second air pump electrical drive signal to the air pump and a third EAM electrical drive signal to the EAM membrane, time point "G" can represent a seventh event. A third displacement force that is periodic in nature and has a third frequency and amplitude level can be generated. It can be seen that the third displacement force can be greater than the first displacement force and the second displacement force. For example, the third frequency can be higher than the first frequency of the first displacement force and the second frequency of the second displacement force, but the third amplitude level can be lower than the first amplitude level of the first displacement force and the second amplitude level of the second displacement force. As a result, the third displacement force can be higher than the first displacement force and the second displacement force (during time points "C" and "E", respectively).For example, the user can adjust the driving parameters (e.g., waveform, voltage, and frequency level) of the air pump electrical drive signal, and / or modulate the EAM electrical drive signal applied to the EAM membrane. As a result, by adjusting the driving parameters of the air pump electrical drive signal, and / or by modulating the EAM electrical drive signal applied to the EAM membrane, the tactile feedback transducer 10 can generate a displacement force with varying amplitudes and frequency levels.

[0070] According to various embodiments, a multi-level haptic feedback transducer may thus be provided.Furthermore, a multi-level haptic feedback interface comprising one or more haptic feedback transducers may also be provided.

[0071] Advantageously, a tactile feedback transducer including an air pump can provide a controllable gas pressure to the EAM film, because the drive parameters (e.g., drive voltage, amplitude, and frequency) supplied to the air pump can be modulated by the user. Alternatively or additionally, the electrical drive signal applied to the EAM film can be modulated by the user. As a result, the displacement force and deformation level of the tactile feedback transducer are highly controllable. In addition, the tactile feedback transducer according to multiple embodiments of the present disclosure may require lower power consumption, because the air pump is incorporated, so the EAM film does not need to be continuously excited. For example, the air pump can provide a steady-state holding force, and therefore, the EAM film does not need to be continuously excited to generate a tactile feedback force that the user can perceive.

[0072] The multi-stage tactile feedback transducer and the multi-stage tactile feedback interface according to multiple embodiments can provide a multi-stage shape change and / or hold touch interface. The interface can generate a large protrusion force and can include a tactile feedback effect of surface frequency modulation. As a result, the user can experience a significant enhancement of perceptible feedback and holding force, as well as an improvement in post-relaxation problems. In addition, the tactile feedback transducer can provide a fast response time with low power consumption.

[0073] Although the present disclosure has been specifically shown and described with reference to specific embodiments, it will be appreciated by those skilled in the art that various changes may be made in form and detail without departing from the spirit and scope of the present invention as defined by the appended claims. Therefore, the scope of the present invention is indicated by the appended claims, and therefore it is intended to include all changes within the equivalent meaning and scope of the claims.

Claims

1. A tactile feedback transducer (10), comprising: An electroactive material (EAM) film (11) is disposed on a substrate (13), wherein the EAM film comprises an EAM layer (12) configured to provide a mechanical response in response to an electrical drive signal; and a gas pump (14) configured to control the pressure of a gas (15) applied to the side of the EAM film facing the substrate, The tactile feedback transducer (10) provides multi-level tactile feedback by modulating the electrical drive signal provided to the EAM film (11) and combining the control of the pressure of the gas (15) provided by the gas pump.

2. The tactile feedback transducer (10) according to claim 1, further comprising an elastic cover layer (18) arranged on the EAM film (11).

3. The tactile feedback transducer (30) of claim 1, wherein the air pump (14) comprises a stack of micro-blowers (16).

4. The tactile feedback transducer (40) according to any one of claims 1 to 3, wherein the EAM film comprises a center piece (17) superimposed on the EAM layer (12), The center piece (17) is configured to deform when pressure from the gas (15) applied to the EAM membrane (11) is applied.

5. The tactile feedback transducer (10) according to any one of claims 1 to 3, wherein the EAM layer (12) comprises one or more slits (72) providing openings through the thickness of the EAM layer (12), and / or The EAM layer (12) includes one or more open windows (81), wherein the open windows provide openings through the thickness direction of the EAM layer (12).

6. The tactile feedback transducer (10) according to any one of claims 1 to 3, The EAM layer (12) includes one or more recessed portions (73) extending through a thickness direction of the EAM layer (12).

7. The tactile feedback transducer (10) according to any one of claims 1 to 3, The thickness of the EAM layer (12) decreases from the outer portion of the EAM layer (64) to the inner portion of the EAM layer (65).

8. The tactile feedback transducer (10) according to claim 7, further comprising a fastener (90), wherein the EAM layer (12) is mechanically attached to the substrate (13) by the fastener (90).

9. The tactile feedback transducer (10) according to claim 8, wherein the fastener (90) comprises at least one of a pin, a roller support (92) or a wave spring (94), and / or The fastener (90) comprises a female or male clamping member.

10. The tactile feedback transducer (10) according to any one of claims 1 to 3, The EAM layer (12) includes a plurality of segments (91) extending radially from a center (62).

11. The tactile feedback transducer (10) according to claim 10, wherein the segments (63) are separated from each other in the radial direction by a plurality of cutouts.

12. A tactile feedback interface (100), comprising: A tactile feedback transducer (10) according to any one of claims 1 to 11, or Two or more tactile feedback transducers (10) according to any one of claims 1 to 11 sharing a common substrate (130).

13. The tactile feedback interface (110) of claim 12, further comprising: An additional tactile feedback transducer (111) without an air pump; as well as an air channel (112) for air flow from at least one of the air pumps of one or more of the tactile feedback sensors (10), The air passage (112) comprises a corresponding valve (113) configured to control the air flow.

14. The tactile feedback interface of claim 12, further comprising an electrical drive circuit, wherein the electrical drive circuit is configured to provide a first EAM electrical drive signal to the EAM layer, The electric drive circuit is configured to provide a first air pump electric drive signal to the air pump.

15. The tactile feedback interface of claim 14, wherein the electrical drive circuit is configured to provide: a second EAM electrical drive signal having a different amplitude than the first EAM electrical drive signal, and / or A second air pump electrical drive signal having a different amplitude than the first air pump electrical drive signal.

16. The tactile feedback interface of claim 15, wherein the first EAM electrical drive signal or the second EAM electrical drive signal can be modulated based on the drive voltage, waveform or frequency of the EAM electrical drive signal, and / or The first air pump electric drive signal or the second air pump electric drive signal can be modulated based on the drive voltage, waveform or frequency of the air pump electric drive signal.

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