TECHNICAL FIELD

[0001] The present disclosure relates to a device for receiving a tactile input from a user. The present disclosure further relates to a system for receiving a tactile input from a user.

BACKGROUND

[0002] The following discussion of the background art is intended to facilitate an understanding of the present disclosure only. It should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was published, known or is part of the common general knowledge of the person skilled in the art in any jurisdiction as of the priority date of the disclosure.

[0003] Tactile-enabled devices often include a number of control elements, each associated with a command signal for executing a user’s desired function. Recently, intuitive tactile- enabled devices have been manufactured, where the control elements remain invisible to the user until demanded. This is enabled by actuators which control the morphing of the control elements from the device.

[0004] Such conventional intuitive devices often include a large number of actuators, since each control element is controlled by one or more actuators. Depending on a user’s requirements, multiple control elements may need to be visible to the user, and accordingly, multiple actuators are activated to control the morphing of the control elements from the device. This results in high power consumption and energy wastage, in particular, if the control element has to morph out from the device for an extended duration.

[0005] In addition, due to the large number of actuators, conventional intuitive devices may be large and bulky, and may therefore be aesthetically unappealing to the user.

[0006] Accordingly, there exists a need for an improved device for receiving a tactile input from a user, that seeks to address at least one of the aforementioned issues.

SUMMARY

[0007] The disclosure was conceptualized to provide an improved device for receiving a tactile input from a user, where a plurality of input members is designed to morph from the device when demanded. To this end, the improved device enables the control of multiple input members with a reduced number of actuators, due to the use to electroactive polymer actuators. In particular, a single actuator may control the morphing of more than one input member, leading to reduced power consumption and energy savings. Furthermore, the reduced number of actuators and the use of electroactive polymer actuators (which are small in size) in the improved device allows for miniaturization of the device, which may be aesthetically appealing to the user. The disclosure therefore provides a smaller intuitive “function-on-demand” device with improved energy efficiency. According to an aspect of the disclosure, a device for receiving a tactile input from a user according to claim 1 is provided. Exemplary embodiments of the device are described in the dependent claims.

[0008] According to one aspect of the disclosure, there is provided a device for receiving a tactile input from a user, the device comprising: an input pad comprising a plurality of input members extendable from the input pad along a first direction; at least one actuator arranged to contact at least one of the plurality of input members in a manner such that an application of an electrical voltage to the at least one actuator generates an electrostatic compressive force which urges the at least one of the plurality of input members along the first direction; a first sensor arranged to detect an approaching tactile input from the user; and a controller arranged in signal communication with the first sensor and the at least one actuator and configured to generate the electrical voltage when the approaching tactile input is detected.

[0009] In various embodiments, the urging of the at least one of the plurality of input members along the first direction causes the at least one of the plurality of input members to move in a manner which opposes the electrostatic compressive force.

[0010] In various embodiments, the device further comprises a frame comprising a plurality of openings arranged in a matrix arrangement, in a second direction perpendicular to the first direction and in a third direction perpendicular to the first direction and the second direction, each one of the plurality of input members arranged to be in alignment with a respective one of the plurality of openings, along the first direction, the second direction and the third direction, wherein the urging of the at least one of the plurality of input members along the first direction, causes the at least one of the plurality of input members to protrude from the respective one of the plurality of openings.

[0011] In various embodiments, the device further comprises a second sensor arranged to measure a force of the tactile input and/or a duration of the tactile input.

[0012] In various embodiments, the controller is in signal communication with the second sensor, and configured to determine if the measured force is greater than a predefined threshold force; and/or determine if the duration of the tactile input is greater than a predefined threshold duration.

[0013] In various embodiments, the second sensor is further configured to provide a haptic feedback, if it is determined that the measured force is greater than the predefined threshold force and/or the duration is greater than the predefined threshold duration.

[0014] In various embodiments, the input pad comprising the plurality of input members comprises a rigid material having a flexural modulus ranging from 1.0 GPa to 10.0 GPa.

[0015] In various embodiments, the at least one actuator comprises an electroactive polymer.

[0016] In various embodiments, the at least one actuator comprises a dielectric elastomer.

[0017] In various embodiments, the controller is configured to generate the electrical voltage based on an input voltage, wherein the input voltage comprises an AC power or a DC power.

[0018] In various embodiments, the controller is further configured to modify a waveform of the input voltage.

[0019] According to another aspect of the disclosure, there is provided a system for receiving a tactile input from a user, the system comprising: an input pad comprising a plurality of input members extendable from the input pad along a first direction; at least one actuator arranged to contact at least one of the plurality of input members in a manner such that an application of an electrical voltage to the at least one actuator generates an electrostatic compressive force which urges the at least one of the plurality of input members along the first direction; a first sensor arranged to detect an approaching tactile input from the user; and a controller arranged in signal communication with the first sensor and the at least one actuator, and configured to generate the electrical voltage when the approaching tactile input is detected. [0020] According to another aspect of the disclosure, there is provided a method for manufacturing a device for receiving a tactile input from a user, the method comprising: providing an input pad comprising a plurality of input members extendable from the input pad along a first direction; providing at least one actuator arranged to contact at least one of the plurality of input members in a manner such that an application of an electrical voltage to the at least one actuator generates an electrostatic compressive force which urges the at least one of the plurality of input members along the first direction; providing a first sensor arranged to detect an approaching tactile input from the user; and providing a controller arranged in signal communication with the first sensor and the at least one actuator, and configured to generate the electrical voltage when the approaching tactile input is detected. [0021] According to various embodiments, the device may be a tactile-enabled device such as but not limited to user interfaces or control panels.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The disclosure will be better understood with reference to the detailed description when considered in conjunction with the non-limiting examples and the accompanying drawings, in which:

- FIG. 1 shows a perspective view of a device 100 for receiving an input from a user, in a disassembled configuration, wherein inset (A) shows an exploded view of the assembly of an actuator 140 and an input pad 150 of the device 100;

- FIG. 2 shows the same perspective view of the device 100 for receiving an input from a user in an assembled configuration, and a corresponding cross-sectional view of the arrangement of the actuator 140 and a plurality of input members 152 of the input pad 150, in the (A) inactivated (OFF) state, and in the (B) activated (ON) state; and

- FIG. 3 shows a method 300 for manufacturing a device for receiving a tactile input from a user.

DETAILED DESCRIPTION

[0023] The following detailed description refers to the accompanying drawings that show, by way of illustration, specific details and embodiments in which the disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure. Other embodiments may be utilized and structural, and logical changes may be made without departing from the scope of the disclosure. The various embodiments are not necessarily mutually exclusive, as some embodiments can be combined with one or more other embodiments to form new embodiments.

[0024] Features that are described in the context of an embodiment may correspondingly be applicable to the same or similar features in the other embodiments. Features that are described in the context of an embodiment may correspondingly be applicable to the other embodiments, even if not explicitly described in these other embodiments. Furthermore, additions and/or combinations and/or alternatives as described for a feature in the context of an embodiment may correspondingly be applicable to the same or similar feature in the other embodiments.

[0025] In the context of various embodiments, the articles “a”, “an” and “the” as used with regard to a feature or element include a reference to one or more of the features or elements. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

[0026] While terms such as “first”, “second” etc., may be used to describe various directions, such directions are not limited by the above terms. The above terms are used only to distinguish one direction from another, and do not define an order and/or significance of the directions.

[0027] Throughout the description, the term “tactile input”, as used herein, may refer to a pressure or force applied on an input member, due to the touch of the user. Accordingly, the term “approaching tactile input” may refer to an approaching or incoming input due to the touch of the user, for example, when the user’s hand is moving towards or is near, e.g. within a range to less than 10cm or less than 5 cm from the device.

[0028] Throughout the description, the term “input members”, as used herein, may refer to tactile-enabled control elements, e.g. keys, buttons or switches. Each input member may be associated with a command signal for executing a desired function. For example, as a nonlimiting example, one input member may be associated with the command signal of a “volume increase”, while another input member may be associated with the command signal of a “volume decrease”.

[0029] Throughout the description, the term “actuator”, as used herein, may refer to a component of the device that transforms an electrical voltage into a mechanical electrostatic compressive force. In various embodiments, the actuator may comprise an electroactive polymer, such as but not limited to dielectric elastomers or piezoelectric active polymers. In some embodiments, the actuator may be a dielectric elastomer actuator (DEA), comprising a dielectric elastomer which has both elastic (“rubber-like elasticity”) and viscosity properties. Non-limiting examples of dielectric elastomers include acrylic elastomers, silicone elastomers, fluoro-elastomers, polyurethane, natural / synthetic rubbers.

[0030] Throughout the description, the term “electrostatic compressive force”, as used herein, may refer to the compression of the actuator in response to the applied electrical voltage, for example, applied via electrodes arranged on opposing sides of the actuator.

[0031] Throughout the description, the term “urged”, as used herein, may refer to the exertion of the electrostatic compressive force that drives, impels or pushes the input member to move, e.g. extend or protrude, along a first direction.

[0032] Throughout the description, the term “controller”, as used herein, may refer to a circuit, including analog circuits or components, digital circuits or components, or hybrid circuits or components. Any other kind of implementation of the respective functions which will be described in more detail below may also be understood as a "circuit" in accordance with an alternative embodiment. A digital circuit may be understood as any kind of a logic implementing entity, which may be special purpose circuitry or a processor executing software stored in a memory, firmware, or any combination thereof.

[0033] FIG. 1 shows a perspective view of a device 100 for receiving an input from a user, in a disassembled configuration, wherein inset (A) shows an exploded view of the assembly of an actuator 140 and an input pad 150 of the device 100. FIG. 2 shows the same perspective view of the device 100 for receiving an input from a user in an assembled configuration, and a corresponding cross-sectional view of the arrangement of the actuator 140 and a plurality of input members 152 of the input pad 150, in the (A) inactivated (OFF) state, and in the (B) activated (ON) state. As shown in FIG. 2(A), in the inactivated (OFF) state, the plurality of input members 152 may be invisible to the user; and as shown in FIG. 2(B), the plurality of input members 152 may be visible to the user and may take their shape as control elements in the activated (ON) state. The various components of device 100 may be assembled in a first direction DI as shown in FIG. 1, to form the device 100 as shown in FIG. 2(A) and 2(B).

[0034] Referring to FIGS. 1 , 2(A) and 2(B), the device 100 for receiving a tactile input from a user 102, for example, from a user’s finger includes, an input pad 150 including a plurality of input members 152 extendable from the input pad 150 along the first direction DI. The first direction D 1 may be perpendicular to a principal surface of the device 100 facing the user 102. The input pad 150 and each input member 152 may be made of a rigid, e.g. hard material having a flexural modulus ranging from 1.0 GPa to 10.0 GPa. In other words, the rigid, e.g. hard material has a stiffness that allows for motion (e.g., extension) of input members 152 along the first direction DI, thereby enabling the input members 152 to be urged upon application of the electrostatic compressive force. In various embodiments, the input members 152 may be urged in the range of 1 mm to 10 mm, e.g. 5 mm to 10 mm, to morph out of the device 100 in the activated state (see FIG. 2(B)). In some embodiments, the input pad 150 and each of the input members 152 may include a rigid, e.g. hard thermoplastic.

[0035] Device 100 includes at least one actuator 140, arranged to contact at least one of the plurality of input members 152. In the non-limiting example as shown in inset (A) in FIG. 1, the at least one actuator 140 may be placed on the input pad 150, adjacent to and in contact with the at least one of the plurality of input members 152 (as denoted by the dashed arrows), but other arrangements, for example, between the input members 152 may be contemplated. FIG. 1 shows four actuators 140 as a non -limiting example, however the number of actuators 140 may be smaller or greater than four. The at least one actuator 140 may comprise an electroactive polymer, such as a dielectric elastomer. The at least one actuator 140 may therefore be a DEA with high elasticity, and may have a Young’s modulus ranging from 0.001 GPa to 0.1 GPa, allowing the actuator 140 to withstand large compressive forces without deformation. Due to the elastic behavior of the DEA, a compressive force F applied on the actuator 140 causes a reduction in the height (from hl to h2) of the actuator 140, which in turn causes the expansion of a width (from wl to w2) of the actuator 140 (see FIG. 2(A) and 2(B)), as will be explained below.

[0036] The device 100 further includes a controller 160 in signal communication with, i.e. electrically connected to, the first sensor 134 and the at least one actuator 140 (via one or more electrodes), which is configured to generate an electrical voltage when the approaching tactile input is detected. In some embodiments, the controller 160 may be a printed circuit board.

[0037] In use, device 100 transitions between the inactivated state (FIG. 2(A)) and the activated state (FIG. 2(B)), where the plurality of input members 152 take shape as they morph from the frame 130 of the device 100, to provide a topographic surface. As shown in FIG. 2(A), in the inactivated state, the at least one actuator 140 (e.g., the actuators 140 shown in FIG. 1) may have a first height hl in the first direction DI, and a first width wl in the second direction D2 which is perpendicular to the first direction DI. In operation, as the hand of the user 102 nears the device 100, the first sensor 134 generates a signal in response to the detection of the approaching tactile input, and the controller 160 generates an electrical voltage upon the receival of said signal. The electrical voltage is applied to the at least one actuator 140 which causes the at least one actuator 140 to generate an electrostatic compressive force F. As shown in FIG. 2(B), said electrostatic compressive force F causes the compression of the actuator 140 in the first direction DI and expansion of the actuator in the second direction D2, such that a height of the actuator 140 decreases from the first height hl to a second height h2, and the width increases from the first width wl to the second width w2, due to the elastic nature of the actuator 140.

[0038] The expansion of the width to the second width w2 of the actuator 140 in the activated state, urges, e.g. pushes, at least one of the plurality of input members 152 along the first direction DI. In various embodiments, the urging of the at least one of the plurality of input members 152 causes the at least one of the plurality of input members 152 to move (e.g., expand) in a manner which opposes the electrostatic compression force F. As shown in FIG. 2(B), the electrostatic compressive force F may cause compression (reduction in height to the second height h2) of the at least one actuator 140, which causes the at least one of the plurality of input members 152 to extend in the opposing manner (see dashed arrows), to morph out of the device 100. In other words, the at least one of the plurality of input members 152 has an increased height when urged by the electrostatic compressive force F.

[0039] Due to the arrangement and use of materials for the at least one actuator 140, e.g. DEA, and plurality of input members 152, e.g. rigid thermoplastic, a reduced number of actuators 140 is required to activate multiple input members 152 in the improved device 100, leading to reduced power consumption and energy savings, in particular if multiple input members 152 are activated for an extended duration. Furthermore, the reduced number of actuators and the use of DEA which are small in size, allows for miniaturization of the device, which may be aesthetically appealing to the user. Although the use of DEA is disclosed in the improved device 100, the at least one actuator 140 may include piezoelectric actuators as an alternative.

[0040] Device 100 may further include a frame 130 having a first surface 130a arranged to face the user 102, and an opposing second surface 130b. The first direction DI may be perpendicular to the first surface 130a. The frame 130 includes a plurality of openings 132 arranged in a matrix arrangement, in a second direction D2, perpendicular to the first direction DI, and a third direction D3, perpendicular to the first direction DI and the second direction D2. The frame 130 may house the at least one actuator 140 and the input pad 150 in the arrangement as shown in inset (A) of FIG. 1. The frame 130 may cooperate with a rear cover 170 to secure the at least one actuator 140, the input pad 150, and the controller 160 within the frame 130 of device 100. Alternatively, it is contemplated that the controller 160 may be external to the frame 130.

[0041] In various embodiments, each one of the plurality of input members 152 may be in alignment with a respective one of the plurality of openings 132, along the first direction (DI), the second direction (D2), and the third direction (D3), such that the urging of the at least one of the plurality of input members 152 along the first direction DI causes the at least one of the plurality of input members 152 to protrude from the respective one of the plurality of openings 132. Therefore, the plurality of openings 132 guides and controls the urging of the plurality of input members 152 along the first direction DI. In particular, the plurality of openings 132 allows each input member 152 to move, e.g. protrude (in the activated state) and retract (in the inactivated state) only along the first direction DI, in other words the input members 152 have freedom of motion only along the first direction DI due to the openings 132.

[0042] Device 100 may further include a second sensor 120 arranged to measure a force of the tactile input from the user 102 and/or a duration of the tactile input from the user 102. In various embodiments, the second sensor 120 may include a piezoelectric sensor, such as but not limited to polyvinylidene fluoride (PVDF) piezoelectric sensors, poly-L-lactic acid (PLLA) piezoelectric sensors, lead zirconate titanate (PZT) piezoelectric sensors. In some embodiments, the second sensor 120 may comprise a sensor array incorporated into a PVDF polymer layer. The sensor array may include at least one of: a force or pressure sensor, and/or a clock. In various embodiments, the second sensor 120 may be flexible and may be stretched reversibly along the first direction DI as the device 100 transitions between the inactivated (see FIG. 2(A)) and activated states (see FIG. 2(B)). That is, the second sensor 120 accommodates the morphing of the plurality of input members 152, upon demand of the user 102, e.g. approaching tactile input of the user 102.

[0043] In various embodiments, the second sensor 120 may be in signal communication with, i.e. electrically connected to, the controller 160, and may transmit signals corresponding to the measured force or pressure of the tactile input and/or the duration of the tactile input, to the controller 160. The controller 160 may determine, (i.) if the measured force is greater than a predefined threshold force; and/or (ii.) if the duration of the tactile input is greater than a predefined threshold duration. In some embodiments, the predefined threshold force may be greater than or equal to 0.1 N, preferably within the range of 0.1 N to 1 N; and the predefined threshold may be at least 10 milliseconds, preferably within the range of 10 milliseconds to 500 milliseconds. The second sensor 120 may therefore determine that a tactile input from the user 102 is a definitive desire to execute a user 102’s desired function and is not a mistake, if said measurements are above the predefined threshold levels.

[0044] In various embodiments, the second sensor 120 may be further configured to generate a haptic feedback (e.g., in the form of a brief pulse), if it is determined that the measured force is greater than the predefined threshold force and/or the duration is greater than the predefined threshold duration. The haptic feedback may serve as an acknowledgment to the tactile input of the user 102, which may be particularly beneficial for visually-impaired users. [0045] As shown in FIG. 1, in some embodiments, the second sensor 120 may be arranged between a skin layer 110 and the first surface 130a of the frame 130. In some other embodiments, the second sensor 120 may be arranged between the second surface 130b of the frame 130 and the at least one actuator 140 and input pad 150.

[0046] Device 100 may further include the skin layer 110, which may form the interface layer that is configured to contact a user 102’s finger to receive the tactile input from the user 102. The skin layer 110 may include a flexible material such as a flexible polymer and / or textile, which may be stretched reversibly along the first direction DI as the device 100 transitions between the inactivated (see FIG. 2(A)) and activated (see FIG. 2(B)) states. The skin layer 110 may have a flexural modulus within a range of 5 MPa to 50 MPa. The skin layer 110 therefore is able to accommodate the morphing of the plurality of input members 152.

[0047] In various embodiments, the morphing pattern of the plurality of input members 152 from the device 100, specifically, from the plurality of openings 132 of the frame 130, may be adapted based on an input voltage.

[0048] In some embodiments, the input voltage may be a direct current (DC) power supplied from DC power sources, e.g. batteries to provide a constant voltage to the device 100, to allow the device 100 to operate between the inactivated and activated states.

[0049] In some other embodiments, the input voltage may be an alternating current (AC) power providing an input voltage which exhibits periodic changes in current direction, and may for example have a sinusoidal waveform. When the input voltage comprises an AC power, the at least one actuator 140 may transition between inactivated (where the at least one actuator 140 is uncompressed) and activated (where the at least one actuator 140 is electrostatically compressed) states within a short duration, e.g. in accordance with the period of the sinusoidal waveform. As such, the plurality of input members 152 may be seen to have a vibrational motion as it protrudes (activated) and retracts (inactivated) from the device 100.

[0050] The controller 160 may be configured to modify, e.g. modulate a waveform of input voltage. In some embodiments, the DC power may be modified to form a pulse-width modulated (pulse-duration modulated) waveform to regulate the voltage supplied to the device 100. The application of a DC input power in the form of a pulse-width modulated waveform allows the at least one actuator 140 to remain compressed with reduced power consumption. That is, the electrical voltage may be constantly applied to the at least one actuator 140 such that it maintains its compressed state (reduced height h2 and expanded width w2 as shown in FIG. 2(B)), and maintains the protrusion of at least one of the plurality of input members 152 from the device 100. Accordingly, the plurality of input members 152 may be visible to the user 102 for an extended duration. It is contemplated that the controller 160 may modify a waveform of the AC power, e.g. into the pulse-width modulated waveform; or may modify the waveform of the input voltage, according to the requirements of the user or device 100. It is further contemplated that the device 100 may also include one or more rectifiers to convert the input voltage and/or transformers to raise or lower the input voltage according to the use of the device 100.

[0051] According to another aspect of the disclosure, there is provided a system for receiving a tactile input from a user comprising an input pad comprising a plurality of input members extendable from the input pad along a first direction; at least one actuator arranged to contact at least one of the plurality of input members in a manner such that an application of an electrical voltage to the at least one actuator generates an electrostatic compressive force which urges the at least one of the plurality of input members along the first direction; a first sensor arranged to detect an approaching tactile input from the user; and a controller arranged in signal communication with the first sensor and the at least one actuator, and configured to generate the electrical voltage when the approaching tactile input is detected. The system may be based on the device 100 as described with reference to FIGS. 1, 2(A) and 2(B), and repeated descriptions will be omitted.

[0052] In various embodiments of the system, the urging of the at least one of the plurality of input members along the first direction causes the at least one of the plurality of input members to move (e.g., expand) in a manner which opposes the electrostatic compressive force. [0053] In various embodiments, the system further includes a frame comprising a plurality of openings arranged in a matrix arrangement, in a second direction perpendicular to the first direction, and a third direction perpendicular to the first direction and the second direction, each one of the plurality of input members arranged to be in alignment with a respective one of the plurality of openings, along the first direction, the second direction and the third direction, wherein the urging of the at least one of the plurality of input members along the first direction, causes the at least one of the plurality of input members to protrude from the respective one of the plurality of openings.

[0054] In various embodiments, the system further includes a second sensor arranged to measure a force of the tactile input and/or a duration of the tactile input, wherein the controller is in signal communication with the second sensor, and configured to determine if the measured force is greater than a predefined threshold force; and/or determine if the duration of the tactile input is greater than a predefined threshold duration.

[0055] In various embodiments of the system, the controller generates the electrical voltage based on an input voltage, wherein the input voltage comprises an AC power or a DC power.

[0056] FIG. 3 shows a method 300 for manufacturing a device for receiving tactile input from a user comprising, in accordance with yet another aspect of the disclosure. Method 300 includes: providing an input pad comprising a plurality of input members extendable from the input pad along a first direction (step 302); providing at least one actuator arranged to contact at least one of the plurality of input members in a manner such that an application of an electrical voltage to the at least one actuator generates an electrostatic compressive force which urges the at least one of the plurality of input members along the first direction (step 304); providing a first sensor arranged to detect an approaching tactile input from the user (step 306); and providing a controller arranged in signal communication with the first sensor and the at least one actuator, and configured to generate the electrical voltage when the approaching tactile input is detected (step 308). The method 300 of manufacture of the device for receiving tactile input from a user may refer to the device 100 described with reference to 1, 2(A) and 2(B), and repeated descriptions will be omitted.

[0057] In various embodiments, the urging of the at least one of the plurality of input members along the first direction (step 302), causes the at least one of the plurality of input members to move in a manner which opposes the electrostatic compressive force.

[0058] In various embodiments, method 300 further comprises: providing a second sensor arranged to measure a force of the tactile input and/or a duration of the tactile input (step 310). [0059] In various embodiments, the input pad comprising the plurality of input members may include a rigid material having a flexural modulus ranging from 1.0 GPa to 10.0 GPa.

[0060] In various embodiments, at least one actuator may include an electroactive polymer, and in some embodiments, the electroactive polymer may be a dielectric elastomer.

[0061] The present disclosure provides an intuitive “function-on-demand” device with improved energy efficiency, by enabling the control of multiple input members with a reduced number of actuators. In addition, the reduced number of actuators and the use of electroactive polymer actuators, e.g. DEA allows for miniaturization of the improved device, which may be aesthetically appealing to the user.

[0062] While the disclosure has been particularly shown and described with reference to specific embodiments, it should be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the scope of the disclosure as defined by the appended claims. The scope of the disclosure is thus indicated by the appended claims.