GB2611075A

GB2611075A - An actuator device, a method of making an actuator device, and a system for providing a morphable surface

Info

Publication number: GB2611075A
Application number: GB2113726.0A
Authority: GB
Inventors: renaud Michael; Novianto Depari Leonardus
Original assignee: Continental Automotive Technologies GmbH
Current assignee: Continental Automotive Technologies GmbH
Priority date: 2021-09-27
Filing date: 2021-09-27
Publication date: 2023-03-29
Also published as: GB202113726D0

Abstract

An actuator device, a method of making an actuator device, and a system for providing a morphable surface. The actuator device 306 comprises a bistable structure, such as a buckle beam 308, configurable between first and second stable positions, and first and second conductor elements, such as smart or shape memory alloy (SMA) wires 318, 320, deformable when electrical current passes therethrough. The first and second conductor elements engage the bistable structure such that deformation of the first or second conductor element configures the bistable structure into the first or second stable position. A system 300 for providing a morphable surface comprises a sheet layer 302 having a first and second opposed surfaces and at least one actuator device 306 coupled to one surface and configured to deform the sheet layer at a location corresponding to the bistable structure such that an external protrusion is formed on the first surface of the sheet layer when the bistable structure switches from the first stable position to the second stable position.

Description

AN ACTUATOR DEVICE, A METHOD OF MAKING AN ACTUATOR DEVICE, AND A SYSTEM FOR PROVIDING A MORPHABLE SURFACE

TECHNICAL FIELD

The present disclosure relates broadly to an actuator device, a method of making an actuator device, and a system for providing a morphable surface.

BACKGROUND

Morphing buttons may be found in a diverse range of applications such as is automotive interior design, consumer electronics and appliances, aeronautics etc. Morphing buttons are typically erected from seamless surfaces using a cam motor arrangement or stepper motors.

However, the cam motor or the stepper motors arrangements are expensive, 20 slow and consume a large amount of electrical power. As a result, the use of cam motor or the stepper motors arrangements may not be a viable option for certain commercial product applications.

Thus, there is a need for an actuator device, a method of making an actuator device, and a system for providing a morphable surface, which seek to address or at least ameliorate one of the above problems.

SUM MARY

In accordance with an aspect of the present disclosure, there is provided an actuator device comprising, a bistable structure that is configurable into a first stable position or a second stable position, and a first conductor element and a second conductor element, each of the conductor elements respectively capable of deformation when electrical current passes therethrough; characterised in that the first conductor element and second conductor element are arranged to engage with the bistable structure, such that deformation of the first conductor element or second conductor element configures the bistable structure into the first stable position or the second stable position.

The first conductor element may be arranged such that deformation of the first conductor element applies a mechanical force on the bistable structure, to configure the bistable structure in the second stable position.

The second conductor element may be arranged such that deformation of the second conductor element applies another mechanical force to the bistable structure, to configure the bistable structure in the first stable position.

The bistable structure may form a cavity when configured in the first stable position; and a protrusion when configured in the second stable position.

The bistable structure may comprise a buckled beam, said buckled beam comprises fixed ends and a buckling middle portion, in that applying a transverse mechanical force to the buckling middle portion configures the bistable structure, wherein a direction of the applied transverse mechanical force determines whether the bistable structure is in the first stable position or the second stable position.

The first conductor element may be arranged on a side of the buckling middle portion, such that deformation of the first conductor element applies a transverse mechanical force of a first direction, to configure the bistable structure in the second stable position.

The second conductor element may be arranged on an other side of the buckling middle portion opposite the first conductor element, such that deformation of the second conductor element applies a transverse mechanical force of a second direction, to configure the bistable structure in the first stable position; said second direction substantially opposite that of the first direction.

Each of the first conductor element and second conductor element may comprise a length of wire that is configured to straighten in response to an electrical current passing therethrough.

The second conductor element may be further configured to provide haptic 10 feedback in response to an external force applied thereon.

The hapfic feedback may be in the form of a vibration generated by an electrical current passing through the second conductor element.

Each of the first conductor element and the second conductor element may be formed from a smart memory alloy.

The electrical current that is passed through the first conductor element for switching the bistable structure from the first stable position to the second stable position and the electrical current that is passed through the second conductor element for switching the bistable structure from the second stable position to the first stable position may be transient pulsed electrical currents.

In the first stable position of the bistable structure, the first conductor element may be in a deformed state and the second conductor element may be in an undeformed state; and in the second stable position of the bistable structure, the first conductor element may be in an undeformed state and the second conductor element may be in a deformed state.

The electrical current passing through the second conductor element for providing hapfic feedback may have an amplitude of from 5 mA to 999 mA.

The electrical current for deforming the first and second conductor elements may have an amplitude of from 5 A to 99 A. In accordance with another aspect of the present disclosure, there is provided a system for providing a morphable surface, the system comprising, a sheet layer comprising a first surface and a second surface disposed opposite to the first surface; and at least one actuator device as disclosed herein coupled to the second surface of the sheet layer, characterised in that the actuator device is configured to deform the sheet layer at a location corresponding to the bistable structure of the actuator device, such that an external protrusion is formed on the first surface of the sheet layer when the bistable structure switches from the first stable position to the second stable position.

The first surface of the sheet layer may be substantially flat and devoid of the external protrusion at the location corresponding to the bistable structure of the actuator device when the bistable structure is in the first stable position.

The sheet layer may be made from a substantially pliable material such the sheet layer is configured to be deformable in response to a change in the stable position of the bistable structure.

In accordance with another aspect of the present disclosure, there is provided a method of making an actuator device, the method comprising, providing a bistable structure that is configurable into a first stable position and a second stable position; providing a first conductor element and a second conductor element that are capable of deformation when electrical current passes through either of the first and second conductor elements; and arranging the first conductor element and the second conductor element to engage with the bistable structure, such that the deformation of the first or second conductor elements configures the bistable structure into the first stable position or the second stable position.

BRIEF DESCRIPTION OF THE DRAWINGS

Example embodiments of the invention will be better understood and readily apparent to one of ordinary skill in the art from the following written description, by 5 way of example only, and in conjunction with the drawings, in which: FIG. 1 is a schematic block diagram of an actuator device in an example embodiment.

FIG. 2A is a first perspective view drawing of a sheet layer having a morphable surface in an example embodiment.

FIG. 2B is a cross sectional view drawing of the sheet layer taken along the line AA of FIG. 2A in the example embodiment.

FIG. 2C is a second perspective view drawing of the sheet layer in the example embodiment.

FIG. 2D is a cross sectional view drawing of the sheet layer taken along the 20 line BB of FIG. 20 in the example embodiment.

FIG. 3A is a first perspective view drawing of a system for providing a morphable surface in an example embodiment.

FIG. 3B is a cross sectional view drawing of the actuator device taken along the line CC of FIG. 3A in the example embodiment.

FIG. 3C is a second perspective view drawing of the system for providing a morphable surface in the example embodiment.

FIG. 3D is a cross sectional view drawing of the actuator device taken along the line DD of FIG. 3C in the example embodiment.

FIG. 4A is a first perspective view drawing of a system for providing a morphable surface in an example embodiment.

FIG. 4B is an exploded perspective view drawing of the system of FIG. 4A in the example embodiment.

FIG. 40 is a cross sectional view drawing of the system taken along the line EE of FIG. 4B in the example embodiment.

FIG. 40 is a second perspective view drawing of the system for providing a morphable surface in the example embodiment.

FIG. 4E is an exploded perspective view drawing of the system of FIG. 40 in 15 the example embodiment.

FIG. 4F is a cross sectional view drawing of the system taken along the line FF of FIG. 4E in the example embodiment.

FIG. 5 is a schematic flowchart for illustrating a method of making an actuator device in an example embodiment.

FIG. 6 is a schematic drawing of a computer system suitable for implementing an example embodiment.

DETAILED DESCRIPTION

Example, non limiting embodiments may provide an actuator device, a 30 method of making an actuator device, and a system for providing a morphable surface.

FIG. 1 is a schematic block diagram of an actuator device 100 in an example embodiment. The actuator device 100 comprises a bistable structure 102 that is configurable into a first stable position 110 or a second stable position 112; and a first conductor element 104 and a second conductor element 106, each of the conductor elements respectively capable of deformation when electrical current passes therethrough; and a processing module 108 coupled to the first conductor element 104 and the second conductor element 106 for controlling and monitoring the operation of the actuator device 100. The first and second conductor elements 104, 106 are arranged to engage with the bistable structure 102, such that deformation of the first or second conductor elements 104, 106 configures the bistable structure 102 into the first stable position 110 or the second stable position 112.

The bistable structure 102 is configured to have two stable equilibrium states or stable positions, that is, the first stable position 110 and the second stable position 112. The bistable structure 102 is configured to switch between the first stable position 110 and the second stable position 112 (represented by a bidirectional arrow in FIG. 1). The bistable structure 102 may be capable of resting in either of the two stable positions unless a directional force is applied to bias the bistable structure 102 towards the other stable position. The bistable structure 102 may be configured to switch (e.g., by deforming, transforming, morphing) between the first stable position 110 and the second stable position 112 by undergoing a change in shape, size, position (e.g., rotation, translation), or a combination thereof. The bistable structure 102 may be configured to switch from the first stable position 110 to the second stable position 112 in response to a first directional force biasing the bistable structure 102 towards the second stable position 112. The bistable structure 102 may be configured to switch from the second stable position 112 to the first stable position 110 in response to a second opposite directional force biasing the bistable structure 102 towards the first stable position 110.

The bistable structure 102 may be in the form of a beam, a sheet/membrane or more elaborated/complex structures, capable of exhibiting physical bistability (i.e., capable of resting in either of two stable equilibrium physical states). For example, an elaborated bistable structure may be created using kirigami and/or self folding origami design principles such that the structure is capable of switching between stable states based on fold lines and reinforced regions created in the structure. The bistable structure 102 may be made of materials that are substantially flexible and are capable of bending, flexing, twisting, rotating, and/or buckling under load, e.g., a buckled beam. The bistable structure 102 may also be made of materials that are substantially rigid, e.g., an assembly of rigid bodies connected by hinges and capable of switching from one stable state e.g., 110 to another stable state e.g., 112.

The bistable structure 102 may function to deform or morph a surface by switching between the two stable positions 110, 112. The bistable structure 102 may form a cavity when configured in the first stable position 110; and a protrusion when configured in the second stable position 112. In an example application of the actuator device 100, the bistable structure 102 may be coupled to a surface, e.g., a substantially flat, seamless surface, and may be configured such that the switch from the first stable position 110 to the second stable position 112 results in a morphing or deformation of the surface. The deformation of the surface may be manifested in the form of an external protrusion on the surface. The external protrusion may function as a push button. This may advantageously ensure that no external protrusion or push button is visible on the seamless surface when there is no demand for it. When there is demand for the push button to be visible and erected, the bistable structure 102 deforms the surface, resulting in an apparent push button.

The first conductor element 104 and the second conductor element 106 functions to actuate/ switch the bistable structure 102 between the first stable position 110 and the second stable position 112. The first and second conductor element (104, 106) are capable of deformation when electrical current passes through either of the first and second conductor elements (104, 106). The bistable structure 102 may be configured to switch from the first stable position 110 to the second stable position 112 when an electrical current is passed through the first conductor element 104. The bistable structure 102 may be further configured to switch from the second stable position 112 to the first stable position 110 when an electrical current is passed through the second conductor element 106. The first conductor element 104 may be arranged such that deformation of the first conductor element 104 applies a mechanical force on the bistable structure 102, to configure the bistable structure 102 in the second stable position 112. The second conductor element 106 may be arranged such that deformation of the second conductor element 106 applies another mechanical force to the bistable structure 102, to configure the bistable structure 102 in the first stable position 110.

In the first stable position 110 of the bistable structure 102, the first conductor element 104 may be in a deformed state and the second conductor element 106 may be in an undeformed state. In the first stable position 110 of the bistable structure 102, the first conductor element 104 may be engaged (i.e., mechanically coupled) with the bistable structure 102 and the second conductor element 106 may be disengaged (i.e., mechanically decoupled) from the bistable structure 102. In the second stable position 112 of the bistable structure 102, the first conductor element 104 may be in an undeformed state and the second conductor element 106 may be in a deformed state. In the second stable position 112 of the bistable structure 102, the first conductor element 104 may be disengaged (i.e., mechanically decoupled) from the bistable structure 102 and the second conductor element 106 may be engaged (i.e., mechanically coupled) with the bistable structure 102. The mechanical coupling of the conductor elements (104, 106) to the bistable structure 102 may facilitate the transmission of mechanical forces therebetween.

The first conductor element 104 may be further configured to apply a first biasing load/force on the bistable structure 102 in a first direction when changing from the deformed state to the undeformed state, causing the bistable structure 102 to switch from the first stable position 110 to the second stable position 112. The switching of the bistable structure 102 from the first stable position 110 to the second stable position 112 may in turn cause the second conductor element 106 to change from the undeformed state to the deformed state.

The second conductor element 106 may be further configured to apply a second biasing load/force on the bistable structure 102 in a second opposite direction when changing from the deformed state to the undeformed state, causing the bistable structure 102 to switch from the second stable position 112 to the first stable position 110. The switching of the bistable structure 102 from the second stable position 112 to the first stable position 110 may in turn cause the first conductor element 104 to change from the undeformed state to the deformed state.

For example, the change from the undeformed state to the deformed state may comprise bending of the first conductor element 104 and the second conductor element 106, or portions thereof; and the change from the deformed state to the undeformed state comprises straightening of the first conductor element 104 and the second conductor element 106, or portions thereof.

The processing module 108 functions to control and monitor the operation of the actuator device 100. For example, the processing module 108 may control the type of stable state of the bistable structure 102 by sending an electrical current through the first conductor element 104 or the second conductor element 106. The processing module 108 may be electrically coupled to the first conductor element 104 and the second conductor element 106 to facilitate the transmission of electrical power and signal.

FIG. 2A is a first perspective view drawing of a sheet layer 200 having a morphable surface in an example embodiment. FIG. 2B is a cross sectional view drawing of the sheet layer 200 taken along the line AA of FIG. 2A in the example embodiment. FIG. 2C is a second perspective view drawing of the sheet layer 200 in the example embodiment. FIG. 2D is a cross sectional view drawing of the sheet layer 200 taken along the line BB of FIG. 2C in the example embodiment.

The sheet layer 200 comprises a first (top) surface 202 and a second (bottom) surface 204 disposed opposite to the first surface 202. The sheet layer 200 may be made from a substantially pliable/ flexible/elastic material such that the sheet layer is capable of being deformed in response to a force applied thereon. For example, the sheet layer 200 may be configured to be deformable in response to a change in the stable position of the bistable structure of the actuator as disclosed herein. For example, the sheet layer 200 may be made from materials which include, but are not limited to, artificial leather, silicone elastomers, acrylic elastomers, polyurethanes, thermoplastic elastomers, copolymers comprising PVDF, pressure sensitive adhesives, fluoroelastomers, polymers comprising silicone and acrylic moieties, and the like. Polymers comprising silicone and acrylic moieties may include copolymers comprising silicone and acrylic moieties, polymer blends comprising a silicone elastomer and an acrylic elastomer, for example.

As shown in FIGS. 2A and 2B, the sheet layer 200 may be in a "morphing off' state such that the first surface 202 is substantially flat. As shown in FIGS. 2C and 2D, the sheet layer 200 may be in a "morphing on" state such that a protrusion, e.g., an external protrusion 206, is formed on the first surface 202. The sheet layer 200 may be configured to reversibly switch between the "morphing off" state and the "morphing on" state by using an actuator as disclosed herein.

The sheet layer 200 having a morphable surface may be used in a system for providing a morphable surface where one or more external protrusions may be configured as buttons e.g., push buttons. The external protrusion 206, e.g., push button, may be configured to control one or more aspects of a machine or a process. For example, the external protrusion 206 may be configured to control the volume level of a sound system, the temperature settings of an air conditioning system, the rolling up/down of window(s) in an automobile, and the like. The external protrusion 206 may be configured to appear when there is a demand to control an aspect of a machine or a process associated with the external protrusion, and further configured to disappear when there is no demand.

FIG. 3A is a first perspective view drawing of a system 300 for providing a morphable surface in an example embodiment. The system 300 comprises a sheet layer 302 having a first (top) surface 304 and a second (bottom) surface (not shown, compare 204 of FIGS 28 and 2D) disposed opposite to the first surface; and an actuator device 306 having a bistable structure configurable into a first stable position or a second stable position, coupled to the second surface of the sheet layer 302. FIG. 3B is a cross sectional view drawing of the actuator device 306 taken along the line CC of FIG. 3A in the example embodiment. FIG. 3C is a second perspective view drawing of the system 300 for providing a morphable surface in the example embodiment. FIG. 3D is a cross sectional view drawing of the actuator device 306 taken along the line DD of FIG. 30 in the example embodiment. For the purposes of illustration, the actuator device 306 is shown above the first surface 304 of the sheet layer 302 in FIGS. 3A and 3C.

In the example embodiment, the sheet layer 302 functions to provide a morphable surface that is configured to be deformable in response to a change in the stable position of the bistable structure. The sheet layer 302 may be made from a substantially pliable/ flexible material. The sheet layer 302 may be in a "morphing off' state such that the first surface 304 is substantially flat (see e.g., FIGS. 2A and 28), and a "morphing on" state such that an external protrusion is formed on the first surface 304 (see e.g., FIGS. 20 and 2D). The system 300 for providing the morphable surface may be useful in applications that require morphable buttons such that the buttons appear on demand and disappear when there is no demand.

The actuator device 306 functions to deform or morph the sheet layer 302 by applying a mechanical force on the sheet layer 302. The actuator device 306 may also function to detect and measure a mechanical force that is applied on the first surface 304 of the sheet layer 302. The actuator device 306 may further function to provide a haptic feedback in response to the mechanical force that is applied on the first surface 304 of the sheet layer 302. The actuator device 306 may be in direct or indirect contact with the bottom surface of the sheet layer 302, as long as the mechanical forces can be transmitted between the actuator device 306 and the sheet layer 302.

The actuator device 306 comprises a bistable structure (compare 102 of FIG. 1) in the form of a longitudinal beam e.g., a bucked beam 308 comprising fixed ends and a buckling middle portion. The buckled beam 308 is supported on a substantially planar support 310. The buckled beam 308 comprises a first end 312 and a second end 314 supported on opposite sides of a circular hole 316 defined in the planar support 310. The actuator device 306 further comprises a first conductor element e.g., a first wire 318 and a second conductor element e.g., a second wire 320 that are arranged to engage with the buckled beam 308. It will be appreciated that the hole may be in the form of other shapes such as a square, rectangle, polygon etc. It will also be appreciated that the buckled beam 308 may be replaced by other structures e.g., a sheet or more elaborated/complex structures that are capable of exhibiting physical bistability (i.e., capable of resting in either of two stable equilibrium physical states).

As shown in FIGS. 3A and 33, the buckled beam 308 is oriented to be substantially parallel to the X axis. The diameter of the circular hole 316 is configured to be shorter than the length of the buckled beam 308 such that the middle portion of the buckled beam 308 is in a buckled or bent configuration when the first end 312 and the second end 314 are attached/fixed to or supported at opposite ends of the circular hole 316.

The buckled beam 308 is capable of resting in either a first stable equilibrium state or stable position and a second stable equilibrium state or stable position. As shown in FIGS. 3A and 3B, the buckled beam 308 is in a first stable position when the buckled beam 308 is buckled downwards in a first direction normal to the planar support 310 along the Y axis (i.e., vertical axis). As shown in FIGS. 3C and 3D, the buckled beam 308 is in a second stable position when the buckled beam 308 is buckled upwards in a second direction normal to the planar support 310 along the Y axis, opposite to the first direction.

The buckled beam 308 is configured such that applying a transverse mechanical force to the buckling middle portion configures the bistable structure, wherein a direction of the applied transverse mechanical force determines whether the bistable structure is in the first stable position or the second stable position. The buckled beam 308 is capable of switching between the first stable position and the second stable position by means of deformation of the first wire 318 and second wire 320 when an electrical current is passed through either of the first wire 318 or the second wire 320. The electrical current for effecting a change in the stable positions of the buckled beam 308 may be a pulse of large amplitude current in the order of several Amperes to tens of Amperes. The electrical current may be in a range of from about 1 A to about 99 A, from about 5 A to about 95 A, from about 10 A to about 90 A, from about 15 A to about 85 A, from about 20 A to about 80 A, from about 25 A to about 75 A, from about 30 A to about 70 A, from about 35 A to about 65 A, from about 40 A to about 60 A, from about 45 A to about 55 A, or from about 50 A to about 55 A. The electrical current that is passed through the first wire 318 or the second wire 320 may be the same or different in terms of amplitude and frequency. The electrical current that is passed through the first wire 318 for switching the bistable structure from the first stable position to the second stable position and the electrical current that is passed through the second wire 320 for switching the bistable structure from the second stable position to the first stable position may be transient pulsed electrical currents.

In the example embodiment, the first wire 318 and second wire 320 are capable of deformation when an electrical current passes therethrough. Each of the first and second wires 318, 320 comprises a length of wire that is configured to straighten in response to an electrical current passing therethrough. As shown in FIG. 3B, the first wire 318 is configured to change from a deformed state to an undeformed state when the electrical current is passed therethrough. The first wire 318 is further configured to apply a first transverse load Fl on the buckled beam 308 in a first direction normal to the planar support 310 when changing from the deformed state to the undeformed state, causing the buckled beam 308 to switch from the first stable position to the second stable position and in turn causing the second wire 320 to change from the undeformed state to the deformed state. As shown in FIG. 3D, the second wire 320 is configured to apply a second transverse load F3 on the buckled beam 308 in a second opposite direction normal to the planar support 310 when changing from the deformed state to the undeformed state, causing the buckled beam 308 to switch from the second stable position to the first stable position and in turn causing the first wire 318 to change from the undeformed state to the deformed state.

The first wire 318 and the second wire 320 may be made/ formed from a smart memory alloy or shape memory alloy (SMA) material, i.e., first SMA wire 318 and second SMA wire 320. A smart memory alloy is an alloy that can be deformed when cold but returns to its pre deformed/undeformed shape when heated, e.g., by passing a current therethrough to heat up the alloy. When a smart memory alloy is in its cold state, the metal can be bent or stretched and will hold those shapes until heated above a transition temperature. Upon heating, the shape changes to its original. When the metal cools again, it will retain the shape, until deformed again.

The smart memory alloy may be an alloy of copper, aluminium and nickel, an alloy of nickel and titanium, an alloy of zinc, copper, gold and iron, an alloy of iron, manganese and silicon, an alloy of copper, zinc and aluminium, and an alloy of copper, aluminium and nickel, for example.

In its undeformed state, the first wire 318 (as shown in FIG. 3C) and the second wire 320 (as shown in FIG. 3A) are oriented to be substantially parallel to the Z axis such that the first wire 318 and the second wire 320 are substantially orthogonal (i.e., 90°) to the buckled beam 308. It will be appreciated that the first wire 318 and the second wire 320 may be oriented at different angles (e.g., 300, 450, 60° etc.) relative to the buckled beam 308, while maintaining their ability to apply the transverse forces on the buckled beam 308.

As shown in FIGS. 3B and 3D, the first wire 318 and the second wire 320 are arranged on opposite sides of the buckled beam 308. The first wire 318 is arranged on a side of the buckling middle portion, such that deformation of the first wire 318 applies a transverse mechanical force of a first direction, to configure the bistable structure in the second stable position. The second wire 320 is arranged on an other side of the buckling middle portion opposite the first wire 318, such that deformation of the second wire 320 applies a transverse mechanical force of a second direction, to configure the bistable structure in the first stable position; said second direction substantially opposite that of the first direction. The first wire 318 is positioned below the buckled beam 308 at the midpoint between the first end 312 and the second end 314. The second wire 320 is positioned above the buckled beam 308 at the midpoint between the first end 312 and the second end 314. In its undeformed state, the first wire 318 and the second wire 320 are disposed in the vicinity of the horizontal XZ plane defined by the planar support 310. The first wire 318 and the second wire 320 are arranged to engage (i.e., to physically contact, mechanically couple) with the buckled beam 308 and to disengage (i.e., to break contact, mechanically decouple) from the buckled beam 308.

In the first stable position of the buckled beam 308, the first wire 318 is engaged with the buckled beam 308 and the second wire 320 is disengaged from the buckled beam 308 (see FIG. 38). In the first stable position of the buckled beam 308, the first wire 318 is in a deformed state where the first wire 318 is bent and/or elongated in a downward direction along the Y axis; and the second wire 320 is in an undeformed state where the second wire 320 is substantially straight and parallel to the Z axis (see FIG. 3A). \Mien the buckled beam 308 is in the first stable position, the first or external surface 304 of the sheet layer 302 is substantially flat or planar, and devoid of an external protrusion at a location corresponding to the buckled beam 308 of the actuator device 306. In other words, the first surface 304 of the sheet layer 302 is substantially flat and devoid of the external protrusion at the location corresponding to the bistable structure of the actuator device 306 when the bistable structure is in the first stable position.

In the second stable position of the buckled beam 308, the first wire 318 is disengaged from the buckled beam 308 and the second wire 320 is engaged with the buckled beam 308 (see FIG. 3D). In the second stable position of the buckled beam 308, the first wire 318 is in an undeformed state where the first wire 318 is substantially straight and parallel to the Z axis; and the second wire 320 is bent and/or elongated in an upward direction along the Y axis (see FIG. 3C). When the buckled beam 308 is in the second stable position, the actuator device 306 is configured to deform the sheet layer 302 at the location corresponding to the buckled beam 308 of the actuator device 306, such that an external protrusion (compare 206 of FIGS. 20 and 2D) is formed on the first surface 304 of the sheet layer 302. In other words, the actuator device 306 is configured to deform the sheet layer 302 at a location corresponding to the bistable structure of the actuator device 306, such that an external protrusion is formed on the first surface 304 of the sheet layer 302 when the bistable structure switches from the first stable position to the second stable position In use, during a switching operation from the first stable position to the second stable position, an electrical current is passed through the first wire 318. The electrical current heats up the first wire 318 and causes the first wire 318 to return to the undeformed state by straightening. The straightening of the first wire 318 produces the traverse load Fl acting on the buckled beam 308 in an upward direction along the Y axis. The transverse load Fl causes the buckled beam 308 to switch to the second stable position by buckling upwards along the Y axis. The first wire 318 disengages from the buckled beam 308 after the buckled beam 308 switch to the second stable position. The buckling of the buckled beam 308 upwards along the Y axis in turn causes the buckled beam 308 to engage the second wire 320 and produces a transverse load F2 acting on the second wire 320. The transverse load F2 causes the second wire 320 to deform (i.e., to bend and/or elongate) upwards along the Y axis. The buckling of the buckled beam 308 upwards along the Y axis also deforms the sheet layer 302 at the location corresponding to the buckled beam 308 of the actuator device 306, causing an external protrusion to be formed on the first surface 304 of the sheet layer 302.

During a switching operation from the second stable position to the first stable position, an electrical current is passed through the second wire 320. The electrical current heats up the second wire 320 and causes the second wire 320 to return to the undeformed state by straightening. The straightening of the second wire 320 produces the traverse load F3 acting on the buckled beam 308 in a downward direction along the Y axis. The transverse load F3 causes the buckled beam 308 to switch to the first stable position by buckling downwards along the Y axis. The second wire 320 disengages from the buckled beam 308 after the buckled beam 308 switch to the first stable position. The buckling of the buckled beam 308 downwards along the Y axis in turn causes the buckled beam 308 to engage the first wire 318 and produces a transverse load F4 acting on the first wire 318. The transverse load F4 causes the first wire 318 to deform (i.e., to bend and/or elongate) downwards along the Y axis. The buckling of the buckled beam 308 downwards along the Y axis also returns the first surface 304 of the sheet layer 302 at the location corresponding to the buckled beam 308 of the actuator device 306 to a substantially flat state that is devoid of the external protrusion.

In the example embodiment, electrical power is only consumed during the switching process between the first and second stable positions of the buckled beam 308 (i.e., the bistable structure). There is no consumption of power to maintain the position of the buckled beam 308, once it is in either one of the stable positions. This advantageously reduces the power consumption of the system 300.

FIG. 4A is a first perspective view drawing of a system 400 for providing a morphable surface in an example embodiment. FIG. 4B is an exploded perspective view drawing of the system 400 of FIG. 4A in the example embodiment. FIG. 4C is a cross sectional view drawing of the system 400 taken along the line EE of FIG. 4B in the example embodiment. FIG. 4D is a second perspective view drawing of the system 400 for providing a morphable surface in the example embodiment. FIG. 4E is an exploded perspective view drawing of the system 400 of FIG. 40 in the example embodiment. FIG. 4F is a cross sectional view drawing of the system 400 taken along the line FF of FIG. 4E in the example embodiment.

The system 400 comprises a sheet layer 402 having a first (top) surface 404 and a second (bottom) surface 424 disposed opposite to the first surface (see FIGS. 4C and 4F); and an actuator device 406 physically coupled to the second surface 424 of the sheet layer 402. For the purposes of illustration, the actuator device 406 is shown above the first surface 404 of the sheet layer 402 in FIGS. 4B and 4E.

The sheet layer 402 and the actuator device 406 function substantially similarly respectively to the sheet layer 302 and the actuator device 306 of FIGS. 3A to 3D.

The sheet layer 402 functions to provide a morphable surface that is deformable in response to a force applied thereon. The sheet layer 402 may be in a "morphing on" state such that an external protrusion 422 is formed on the first surface 404 (see FIG. 4A. The sheet layer 402 may be in a "morphing off" state such that the first surface 404 is substantially flat or planar. The sheet layer 402 may be configured to switch between the "morphing off' state and the "morphing on" state by using the actuator 406.

The actuator device 406 functions to deform or morph the sheet layer 402 by applying a mechanical force on the sheet layer 402. The actuator device 406 also function to detect and measure a mechanical force that is applied on the first surface 404 of the sheet layer 402. The actuator device 406 further functions to provide a haptic feedback in response to the mechanical force that is applied on the first surface 404 of the sheet layer 402. The actuator device 406 may be in direct or indirect contact with the bottom surface 424 of the sheet layer 402, as long as the mechanical forces can be transmitted between the actuator device 306 and the sheet layer 402.

The actuator device 406 comprises a longitudinal beam e.g., buckled beam 408 having a bistable structure (compare 102 of FIG. 1) supported on a substantially planar support 410. The buckled beam 408 comprises a first end 412 and a second end 414 fixed/ supported on opposite sides of a circular hole 416 defined in the planar support 410 and a buckling middle portion. It will be appreciated that the hole may be in the form of other shapes such as a square, rectangle, polygon etc. It will also be appreciated that the buckled beam 408 may be replaced by other structures e.g., a sheet or more elaborated/complex structures that are capable of exhibiting physical bistability (i.e., capable of resting in either of two stable equilibrium physical states).

The actuator device 406 further comprises a first conductor element e.g., a first wire 418 and a second conductor element e.g., a second wire 420 that are arranged to engage with the bistable structure and apply transverse forces on the bistable structure. In its undeformed state, the first wire 418 (as shown in FIG. 4B) and the second wire 420 (as shown in FIG. 4E) are oriented to be substantially parallel to the Z axis such that the first wire 418 and the second wire 420 are substantially orthogonal (i.e., 90°) to the buckled beam 408. It will be appreciated that the first wire 418 and the second wire 420 may be oriented at different angles (e.g., 30°, 45°, 60° etc.) relative to the buckled beam 408, while maintaining their ability to apply the transverse forces on the buckled beam 408.

The buckled beam 408 is capable of resting in either a first stable equilibrium state or stable position and a second stable equilibrium state or stable position. The buckled beam 408 is in a first stable position when the buckled beam 408 is buckled downwards in a first direction normal to the planar support 410 along the Y axis (i.e., vertical axis) (see FIG. 4F). In the first stable position, the buckled beam 408 is disengaged (i.e., not in physical contact, mechanically decoupled) from the second surface 424 of the sheet layer 402. The buckled beam 408 is in a second stable position when the buckled beam 408 is buckled upwards in a second direction normal to the planar support 410 along the Y axis, opposite to the first direction (see FIG. 40). In the second stable position, the buckled beam 408 is engaged (i.6., in physical contact, mechanically coupled) with the second surface 424 of the sheet layer 402 (see FIG. 4F).

As shown in FIG. 4A, the external protrusion 422 is formed on the top surface 404 of the sheet layer 402. The external protrusion 422 functions as a button, e.g., push button, that is configured to control one or more aspects of a machine or a process. The external protrusion 422 is formed when the buckled beam 408 is in the second stable position. In the second stable position of the buckled beam 408, the first wire 418 is disengaged from the buckled beam 408 and the second wire 420 is engaged with the buckled beam 408 (see FIG. 4C). In the second stable position of the buckled beam 408, the first wire 418 is in an undeformed state where the first wire 418 is substantially straight and parallel to the Z axis; and the second wire 420 is bent and/or elongated in an upward direction along the Y axis (see FIG. 4B). In the second stable position of the buckled beam 408, the buckled beam 408 is engaged with the second surface 424 of the sheet layer 402 and deforms the sheet layer 402 at the location corresponding to the buckled beam 408, such that the external protrusion 422 is formed on the first surface 404 of the sheet layer 402.

As shown in FIG. 4D, the external protrusion 422 is not formed on the top surface 404 of the sheet layer 402 when the buckled beam 408 is in the first stable position. In the first stable position of the buckled beam 408, the first wire 418 is engaged with the buckled beam 408 and the second wire 420 is disengaged from the buckled beam 408 (see FIG. 4F). In the first stable position of the buckled beam 408, the first wire 418 is in a deformed state where the first wire 418 is bent and/or elongated in a downward direction along the Y axis; and the second wire 420 is substantially straight and parallel to the Z axis (see FIG. 4E). In the first stable position of the buckled beam 408, the buckled beam 408 is disengaged from the second surface 424 of the sheet layer 402 and the sheet layer 402 at the location corresponding to the buckled beam 408 is returned to an undeformed state that is substantially flat or planar and devoid of the external protrusion 422.

In the example embodiment, the external protrusion 422 is configured to be deformable or depressible in response to a mechanical force applied on the external protrusion 422. For example, as shown in FIG. 4A, when a finger 426 of a user presses on the external protrusion 422 (i.e., downwards in the negative Y axis), the external protrusion 422 deforms slightly and in turn causes the second wire 420 to be deformed or deflected. The deformation or deflection of the second wire 420 results in a variation or change in one or more electrical characteristics/property (e.g., electrical resistance, capacitance etc.) of the second wire 420. For example, the variation in electrical resistance can be measured and related to the mechanical force applied on the external protrusion 422, e.g., the force applied by the finger 426. In other words, the system 400 is capable of measuring the force applied on the external protrusion 422 by measuring the change in electrical resistance.

In the example embodiment, the second wire 420 is further configured to provide haptic feedback in response to an external force applied thereon. Deformation of the second wire 420 in response to the external force results in a corresponding change in an electrical property of the second wire 420 relative to the external force applied; and a haptic feedback is generated when the corresponding change in the electrical property of the second wire 420 exceeds a threshold level. For example, when the change/variation in electrical resistance exceeds a threshold level, haptic feedback is generated in the form of a vibration F5 generated by an electrical current e.g., a low amplitude current passing through the second wire 420.

The vibration F5 that is generated may be configured to vary in terms of strength and/or duration of vibration. Different strength and/or duration of the vibration F5 may be used to provide haptic feedback with variable forces on the user's finger 426 as it interacts with, e.g., depresses, the external protrusion 422. The electrical current for generating the vibration F5 may be in a range of from about 1 mA to about 999 mA, from about 5 mA to about 950 mA, from about 10 mA to about 900 mA, from about 20 mA to about 850 mA, from about 50 mA to about 800 mA, from about 100 mA to about 750 mA, from about 150 mA to about 700 mA, from about 200 mA to about 650 mA, from about 250 mA to about 600 mA, from about 300 mA to about 550 mA, from about 350 mA to about 500 mA, or from about 400 mA to about 450 mA. The electrical current that is passed through the second wire 320 may be a transient pulsed electrical current.

Example embodiments of the system 400 may be applied in a surface type human machine interface with morphable push buttons. The system 400 may advantageously ensure that no external protrusion or push button (i.e., external protrusion 422) is visible on a seamless surface when there is no demand for functions associated with the push button. When there is demand for push buttons to be visible and erected, the first wire 418, e.g., SMA wire 418 is shortly supplied with electrical power by passing an electrical current, e.g., a pulse of large amplitude current. The electrical current actuates the first wire 418 by causing the first wire 418 to straighten, which in turn causes the bistable structure (i.e., buckled beam 408) to switch from the first stable position (or first equilibrium state) to the second stable position (or second equilibrium state). Wien the bistable structure switches to the second stable state, the second wire 420 is deformed and elongated. When switched to the second stable position, the bistable structure deforms the sheet layer 402, e.g., a surface made from artificial leather, resulting in an apparent push button.

Electrical power is only consumed during the switching process. Once the bistable structure is in the second stable position, no power is consumed to maintain the position of the bistable structure When the user presses the push button (i.6., external protrusion 422) using the finger 426, the second wire 420 is deformed, e.g., slightly deflected, which results in a variation of the electrical resistance in the second wire 420. This resistance variation can be measured and related to the force applied by the finger 426. The force measurement can be used to trigger haptic feedback when the resistance variation exceeds a threshold level. Hapfic feedback is generated by sending/supplying an electrical current, e.g., a small amplitude current into the second wire 420.

When there is no demand anymore for the push button to be visible, an electrical current, e.g., a pulse of large amplitude current is sent/supplied to the second wire 420, e.g., SMA wire 420. The electrical current actuates the second wire 420 by causing the second wire 420 to straighten, which in turn causes the bistable structure (i.e., buckled beam 408) to switch from the second stable position to the first stable position. Wien the bistable structure switches to the first stable state, the first wire 418 is deformed and elongated.

FIG. 5 is a schematic flowchart 500 for illustrating a method of making an actuator device in an example embodiment. At step 502, a bistable structure that is configurable into a first stable position and a second stable position is provided. At step 504, a first conductor element and a second conductor element, each of the conductor elements respectively capable of deformation when electrical current passes therethrough, are provided. At step 506, the first conductor element and the second conductor element are arranged to engage with the bistable structure, such that deformation of the first or second conductor elements configures the bistable structure into the first stable position or the second stable position.

In the described example embodiments, the actuator device and system for providing a morphable surface utilises an actuator made of a combination of two conductor elements e.g., Smart Memory Alloy (SMA) wires in conjunction with a bistable structure that allows switching between two equilibrium states. The actuator may be placed below the morphable surface made of a substantially elastic material e.g., artificial leather.

In the described example embodiments, the actuator device and system for providing a morphable surface may advantageously provide a low cost, thin profile and low power consumption device that provides morphing surface, haptic feedback and force sensing (finger pressure) capabilities in a single device.

In the described example embodiments, the actuator device and system for providing a morphable surface may be suitable for various surface type human machine interfaces. For example, the actuator device and system for providing a morphable surface may be applied in a diverse range of applications such as automotive interior design, consumer electronics and appliances, aeronautics etc. For example, in the automotive industry such as in the interior surfaces of an automobile. The actuator device and system for providing a morphable surface may also be applied in wearables and accessories. The actuator device and system for providing a morphable surface may advantageously provide on demand controls in the form of morphable buttons and seamless surfaces where there is no demand for the controls.

Clause 1. An actuator device comprising, a bistable structure that is configurable into a first stable position or a second stable position, and a first conductor element and a second conductor element, each of the conductor elements respectively capable of deformation when electrical current passes therethrough; characterised in that the first conductor element and second conductor element are arranged to engage with the bistable structure, such that deformation of the first conductor element or second conductor element configures the bistable structure into the first stable position or the second stable position.

Clause 2. The actuator device according to clause 1, characterised in that the first conductor element is arranged such that deformation of the first conductor element applies a mechanical force on the bistable structure, to configure the bistable structure in the second stable position.

Clause 3. The actuator device according to clause 1 or 2, characterised in that the second conductor element is arranged such that deformation of the second conductor element applies another mechanical force to the bistable structure, to configure the bistable structure in the first stable position.

Clause 4. The actuator device according to any one of the preceding clauses, characterised in that the bistable structure forms a cavity when configured in the first stable position; and a protrusion when configured in the second stable position.

Clause 5. The actuator device according to any one of the preceding clauses, characterised in that the bistable structure comprises a buckled beam, said buckled beam comprises fixed ends and a buckling middle portion, in that applying a transverse mechanical force to the buckling middle portion configures the bistable structure, wherein a direction of the applied transverse mechanical force determines whether the bistable structure is in the first stable position or the second stable position.

Clause 6. The actuator device according to clause 5, characterised in that the first conductor element is arranged on a side of the buckling middle portion, such that deformation of the first conductor element applies a transverse mechanical force of a first direction, to configure the bistable structure in the second stable position.

Clause 7. The actuator device according to clause 6, characterised in that the second conductor element is arranged on an other side of the buckling middle portion opposite the first conductor element, such that deformation of the second conductor element applies a transverse mechanical force of a second direction, to configure the bistable structure in the first stable position; said second direction substantially opposite that of the first direction.

Clause 8. The actuator device according to any one of clauses 5 to 7, wherein each of the first conductor element and second conductor element comprises a length of wire that is configured to straighten in response to an electrical current passing therethrough.

Clause 9. The actuator device according to any one of the preceding clauses, characterised in that in the second conductor element is further configured to provide haptic feedback in response to an external force applied thereon.

Clause 10. The actuator device according to clause 9, characterised in that the haptic feedback is in the form of a vibration generated by an electrical current passing through the second conductor element.

Clause 11. The actuator device according to any one of the preceding clauses, characterised in that each of the first conductor element and the second conductor element is formed from a smart memory alloy.

Clause 12. The actuator device according to any one of the preceding clauses, characterised in that in the electrical current that is passed through the first conductor element for switching the bistable structure from the first stable position to the second stable position and the electrical current that is passed through the second conductor element for switching the bistable structure from the second stable position to the first stable position are transient pulsed electrical currents.

Clause 13. The actuator device according to any one of clauses 1 to 12, characterised in that in the first stable position of the bistable structure, the first conductor element is in a deformed state and the second conductor element is in an undeformed state; and in the second stable position of the bistable structure, the first conductor element is in an undeformed state and the second conductor element is in a deformed state.

Clause 14. The actuator device according to any one of clauses 10 to 13, characterised in that the electrical current passing through the second conductor element for providing haptic feedback has an amplitude of from about 5 mA to about 15 999 mA.

Clause 15. The actuator device according to any one of clause 1 to 14, characterised in that the electrical current for deforming the first and second conductor elements has an amplitude of from about 5 A to about 99 A. Clause 16. A system for providing a morphable surface, the system comprising, a sheet layer comprising a first surface and a second surface disposed opposite to the first surface; and at least one actuator device according to any one of clause 1 to 15 coupled to the second surface of the sheet layer, characterised in that the actuator device is configured to deform the sheet layer at a location corresponding to the bistable structure of the actuator device, such that an external protrusion is formed on the first surface of the sheet layer when the bistable structure switches from the first stable position to the second stable position.

Clause 17. The system according to clause 16, characterised in that the first surface of the sheet layer is substantially flat and devoid of the external protrusion at the location corresponding to the bistable structure of the actuator device when the bistable structure is in the first stable position.

Clause 18. The system according to clause 16 or 17, characterised in that the sheet layer is made from a substantially pliable material such the sheet layer is configured to be deformable in response to a change in the stable position of the bistable structure.

Clause 19. A method of making an actuator device, the method comprising, providing a bistable structure that is configurable into a first stable position and a second stable position; providing a first conductor element and a second conductor element that are capable of deformation when electrical current passes through either of the first and second conductor elements; and arranging the first conductor element and the second conductor element to engage with the bistable structure, such that the deformation of the first or second conductor elements configures the bistable structure into the first stable position or the second stable position.

The terms "coupled" or "connected" as used in this description are intended to cover both directly connected or connected through one or more intermediate means, unless otherwise stated.

The description herein may be, in certain portions, explicitly or implicitly described as algorithms and/or functional operations that operate on data within a computer memory or an electronic circuit. These algorithmic descriptions and/or functional operations are usually used by those skilled in the information/data processing arts for efficient description. An algorithm is generally relating to a self consistent sequence of steps leading to a desired result. The algorithmic steps can include physical manipulations of physical quantities, such as electrical, magnetic or optical signals capable of being stored, transmitted, transferred, combined, compared, and otherwise manipulated.

Further, unless specifically stated otherwise, and would ordinarily be apparent from the following, a person skilled in the art will appreciate that throughout the present specification, discussions utilizing terms such as "scanning", "calculating", "determining", "replacing", "generating", "initializing", "outputting", and the like, refer to action and processes of an instructing processor/computer system, or similar electronic circuit/device/component, that manipulates/processes and transforms data represented as physical quantities within the described system into other data similarly represented as physical quantities within the system or other information storage, transmission or display devices etc. The description also discloses relevant device/apparatus for performing the steps of the described methods. Such apparatus may be specifically constructed for the purposes of the methods, or may comprise a general purpose computer/processor or other device selectively activated or reconfigured by a computer program stored in a storage member. The algorithms and displays described herein are not inherently related to any particular computer or other apparatus. It is understood that general purpose devices/machines may be used in accordance with the teachings herein. Alternatively, the construction of a specialized device/apparatus to perform the method steps may be desired.

In addition, it is submitted that the description also implicitly covers a computer program, in that it would be clear that the steps of the methods described herein may be put into effect by computer code. It will be appreciated that a large variety of programming languages and coding can be used to implement the teachings of the description herein. Moreover, the computer program if applicable is not limited to any particular control flow and can use different control flows without departing from the scope of the invention.

Furthermore, one or more of the steps of the computer program if applicable may be performed in parallel and/or sequentially. Such a computer program if applicable may be stored on any computer readable medium. The computer readable medium may include storage devices such as magnetic or optical disks, memory chips, or other storage devices suitable for interfacing with a suitable reader/general purpose computer. In such instances, the computer readable storage medium is non transitory. Such storage medium also covers all computer readable media e.g. medium that stores data only for short periods of time and/or only in the presence of power, such as register memory, processor cache and Random Access Memory (RAM) and the like. The computer readable medium may even include a wired medium such as exemplified in the Internet system, or wireless medium such as exemplified in bluetooth technology. The computer program when loaded and executed on a suitable reader effectively results in an apparatus that can implement the steps of the described methods.

The example embodiments may also be implemented as hardware modules. A module is a functional hardware unit designed for use with other components or modules. For example, a module may be implemented using digital or discrete electronic components, or it can form a portion of an entire electronic circuit such as an Application Specific Integrated Circuit (ASIC). A person skilled in the art will understand that the example embodiments can also be implemented as a combination of hardware and software modules.

Additionally, when describing some embodiments, the disclosure may have disclosed a method and/or process as a particular sequence of steps. However, unless otherwise required, it will be appreciated the method or process should not be limited to the particular sequence of steps disclosed. Other sequences of steps may 23 be possible. The particular order of the steps disclosed herein should not be construed as undue limitations. Unless otherwise required, a method and/or process disclosed herein should not be limited to the steps being carried out in the order written. The sequence of steps may be varied and still remain within the scope of the disclosure.

Further, in the description herein, the word "substantially" whenever used is understood to include, but not restricted to, "entirely" or "completely" and the like. In addition, terms such as "comprising", "comprise", and the like whenever used, are intended to be non restricting descriptive language in that they broadly include elements/components recited after such terms, in addition to other components not explicitly recited. For an example, when "comprising" is used, reference to a "one" feature is also intended to be a reference to "at least one" of that feature. Terms such as "consisting", "consist", and the like, may, in the appropriate context, be considered as a subset of terms such as "comprising", "comprise", and the like. Therefore, in embodiments disclosed herein using the terms such as "comprising", "comprise", and the like, it will be appreciated that these embodiments provide teaching for corresponding embodiments using terms such as "consisting", "consist", and the like. Further, terms such as "about", "approximately" and the like whenever used, typically means a reasonable variation, for example a variation of +/-5% of the disclosed value, or a variance of 4% of the disclosed value, or a variance of 3% of the disclosed value, a variance of 2% of the disclosed value or a variance of 1% of the disclosed value.

Furthermore, in the description herein, certain values may be disclosed in a range. The values showing the end points of a range are intended to illustrate a preferred range. Whenever a range has been described, it is intended that the range covers and teaches all possible sub ranges as well as individual numerical values within that range. That is, the end points of a range should not be interpreted as inflexible limitations. For example, a description of a range of 1% to 5% is intended to have specifically disclosed sub ranges 1% to 2%, 1% to 3%, 1% to 4%, 2% to 3% etc., as well as individually, values within that range such as 1%, 2%, 3%, 4% and 5%. The intention of the above specific disclosure is applicable to any depth/breadth of a range.

Different example embodiments can be implemented in the context of data structure, program modules, program and computer instructions executed in a 30 computer implemented environment. A specially configured general purpose computing environment is briefly disclosed herein. One or more example embodiments may be embodied in one or more computer systems, such as is schematically illustrated in FIG. 6.

One or more example embodiments may be implemented as software, such as a computer program being executed within a computer system 600, and instructing the computer system 600 to conduct a method of an example embodiment.

The computer system 600 comprises a computer unit 602, input modules such as a keyboard 604 and a pointing device 606 and a plurality of output devices such as a display 608, and printer 610. A user can interact with the computer unit 602 using the above devices. The pointing device can be implemented with a mouse, track ball, pen device or any similar device. One or more other input devices (not shown) such as a joystick, game pad, satellite dish, scanner, touch sensitive screen or the like can also be connected to the computer unit 602. The display 608 may include a cathode ray tube (CRT), liquid crystal display (LCD), field emission display (FED), plasma display or any other device that produces an image that is viewable by the user.

The computer unit 602 can be connected to a computer network 612 via a suitable transceiver device 614, to enable access to e.g. the Internet or other network systems such as Local Area Network (LAN) or Wide Area Network (WAN) or a personal network. The network 612 can comprise a server, a router, a network personal computer, a peer device or other common network node, a wireless telephone or wireless personal digital assistant. Networking environments may be found in offices, enterprise wide computer networks and home computer systems etc. The transceiver device 614 can be a modem/router unit located within or external to the computer unit 602, and may be any type of modem/router such as a cable modem or a satellite modem.

It will be appreciated that network connections shown are exemplary and other ways of establishing a communications link between computers can be used.

The existence of any of various protocols, such as TCP/IP, Frame Relay, Ethernet, FTP, HTTP and the like, is presumed, and the computer unit 602 can be operated in a client server configuration to permit a user to retrieve web pages from a web based server. Furthermore, any of various web browsers can be used to display and manipulate data on web pages.

The computer unit 602 in the example comprises a processor 618, a Random Access Memory (RAM) 620 and a Read Only Memory (ROM) 622. The ROM 622 can be a system memory storing basic input/ output system (BIOS) information. The RAM 620 can store one or more program modules such as operating systems, application programs and program data.

The computer unit 602 further comprises a number of Input/Output (I/O) interface units, for example I/O interface unit 624 to the display 608, and I/O interface unit 626 to the keyboard 604. The components of the computer unit 602 typically communicate and interface/couple connectedly via an interconnected system bus 628 and in a manner known to the person skilled in the relevant art. The bus 628 can be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures.

It will be appreciated that other devices can also be connected to the system bus 628. For example, a universal serial bus (USB) interface can be used for coupling a video or digital camera to the system bus 628. An IEEE 1394 interface may be used to couple additional devices to the computer unit 602. Other manufacturer interfaces are also possible such as FireVVire developed by Apple Computer and i.Link developed by Sony. Coupling of devices to the system bus 628 can also be via a parallel port, a game port, a PCI board or any other interface used to couple an input device to a computer. It will also be appreciated that, while the components are not shown in the figure, sound/audio can be recorded and reproduced with a microphone and a speaker. A sound card may be used to couple a microphone and a speaker to the system bus 628. It will be appreciated that several peripheral devices can be coupled to the system bus 628 via alternative interfaces simultaneously.

An application program can be supplied to the user of the computer system 600 being encoded/stored on a data storage medium such as a CD ROM or flash memory carrier. The application program can be read using a corresponding data storage medium drive of a data storage device 630. The data storage medium is not limited to being portable and can include instances of being embedded in the computer unit 602. The data storage device 630 can comprise a hard disk interface unit and/or a removable memory interface unit (both not shown in detail) respectively coupling a hard disk drive and/or a removable memory drive to the system bus 628. This can enable reading/writing of data. Examples of removable memory drives include magnetic disk drives and optical disk drives. The drives and their associated computer readable media, such as a floppy disk provide nonvolatile storage of computer readable instructions, data structures, program modules and other data for the computer unit 602. It will be appreciated that the computer unit 602 may include several of such drives. Furthermore, the computer unit 602 may include drives for interfacing with other types of computer readable media.

The application program is read and controlled in its execution by the processor 618. Intermediate storage of program data may be accomplished using RAM 620. The method(s) of the example embodiments can be implemented as computer readable instructions, computer executable components, or software modules. One or more software modules may alternatively be used. These can include an executable program, a data link library, a configuration file, a database, a graphical image, a binary data file, a text data file, an object file, a source code file, or the like. When one or more computer processors execute one or more of the software modules, the software modules interact to cause one or more computer systems to perform according to the teachings herein.

The operation of the computer unit 602 can be controlled by a variety of different program modules. Examples of program modules are routines, programs, objects, components, data structures, libraries, etc. that perform particular tasks or implement particular abstract data types. The example embodiments may also be practiced with other computer system configurations, including handheld devices, multiprocessor systems, microprocessor based or programmable consumer electronics, network PCs, minicomputers, mainframe computers, personal digital assistants, mobile telephones and the like. Furthermore, the example embodiments may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a wireless or wired communications network. In a distributed computing environment, program modules may be located in both local and remote memory storage devices.

The example embodiments may also be practiced with other computer system configurations, including handheld devices, multiprocessor systems/servers, microprocessor based or programmable consumer electronics, network PCs, minicomputers, mainframe computers, personal digital assistants, mobile telephones and the like. Furthermore, the example embodiments may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a wireless or wired communications network. In a distributed computing environment, program modules may be located in both local and remote memory storage devices.

In example embodiments, the actuator is described to comprise a bistable structure having a first stable position and a second stable position. However, it will be appreciated that the actuator is not limited as such and the actuator may comprise, in place of the bistable structure, a multi stable structure such as a tri stable structure, tetra stable structure.

In example embodiments, the actuator is described to comprise two conductor elements. However, it will be appreciated that the actuator is not limited as such, and 30 the actuator may comprise one conductor element or more than two conductor elements.

In example embodiments, the bistable structure is illustrated using a longitudinal beam that is capable of buckling. However, it will be appreciated that the bistable structure is not limited as such and may be more elaborated structures that are capable of exhibiting physical bistability (i.e., capable of resting in either of two stable equilibrium physical states). An example of an elaborated structure may be a bistable kirigami structure in which the structure is capable of switching between stable states based on fold lines and reinforced regions created in the structure.

In example embodiments, the planar support of the actuator device is described to have a circular hole defined thereon. However, it will be appreciated that the circular hole may be in the form of other shapes such as a square, rectangle, polygon etc. In example embodiments, the first and second conductor elements are described to be in the form of wires. However, it will be appreciated that the first and second conductor elements are not limited as such and may be configured to be in other shapes and forms as long as it is capable of applying mechanical forces on the bistable structure.

In example embodiments, the system for providing a morphable surface is described to form a single external protrusion. However, it will be appreciated that the system may be configured to form a plurality of external protrusions by having a corresponding plurality of actuator devices coupled to the second (bottom) surface of the sheet layer.

In example embodiments, the external protrusion that is functioning as a push button may be configured to provide a visual indication on the sheet layer. For example, the external protrusion may be configured to illuminate when it is formed so that a user is able to better visualise the location of the push button. For example, the external protrusion may be configured to display a symbol or pictogram on the sheet layer to enable a user to identify the function(s) associated with the push button.

In example embodiments, the system for providing a morphable surface is described to comprise an actuator coupled to the second (bottom) surface of a sheet layer. However, it will be appreciated that the actuator may be integrated or embedded into the material of the sheet layer.

In example embodiments, the system for providing a morphable surface may further comprise a sensor module for detecting movement e.g., hand movement over the first surface of the sheet layer. When hand movement is detected over the first surface of the sheet layer, a first signal may be triggered to cause the bistable structure to switch to the second stable position and deform the sheet layer to form the external protrusion (e.g., push button). When hand movement is not detected over the first surface of the sheet layer after a period of time, a second signal may be triggered to cause the bistable structure to switch to the first stable position and return the sheet layer to its substantially flat state. It will be appreciated that other triggering mechanisms may be used to activate the push button, e.g., by pressing a switch button, by voice control etc. It will be appreciated by a person skilled in the art that other variations and/or modifications may be made to the specific embodiments without departing from the scope of the invention as broadly described. For example, in the description herein, features of different example embodiments may be mixed, combined, interchanged, incorporated, adopted, modified, included etc. or the like across different example embodiments. The present embodiments are, therefore, to be considered in all respects to be illustrative and not restrictive.

Claims

CLAIMS1. An actuator device (100) comprising, a bistable structure (102) that is configurable into a first stable position (110) or a second stable position (112), and a first conductor element (104) and a second conductor element (106), each of the conductor elements (104, 106) respectively capable of deformation when electrical current passes therethrough; characterised in that the first conductor element (104) and second conductor element (106) are arranged to engage with the bistable structure (102), such that deformation of the first conductor element (104) or second conductor element (106) configures the bistable structure (102) into the first stable position (110) or the second stable position (112).
2. The actuator device (100) according to claim 1, characterised in that the first conductor element (104) is arranged such that deformation of the first conductor element (104) applies a mechanical force on the bistable structure (102), to configure the bistable structure (102) in the second stable position (112).
3. The actuator device (100) according to claim 1 or 2, characterised in that the second conductor element (106) is arranged such that deformation of the second conductor element (106) applies another mechanical force to the bistable structure (102), to configure the bistable structure (102) in the first stable position (110).
4. The actuator device (100) according to any one of the preceding claims, characterised in that the bistable structure (102) forms a cavity when configured in the first stable position (110); and a protrusion when configured in the second stable position (112).
5. The actuator device (100, 306, 406) according to any one of the preceding claims, characterised in that the bistable structure (102) comprises a buckled beam (308, 408), said buckled beam (308, 408) comprises fixed ends and a buckling middle portion, in that applying a transverse mechanical force to the buckling middle portion configures the bistable structure (102), wherein a direction of the applied transverse mechanical force determines whether the bistable structure (102) is in the first stable position (110) or the second stable position (112).
6. The actuator device (100, 306, 406) according to claim 5, characterised in that the first conductor element (104, 318, 418) is arranged on a side of the buckling middle portion, such that deformation of the first conductor element (104, 318, 418) applies a transverse mechanical force of a first direction, to configure the bistable structure (102) in the second stable position (112).
7. The actuator device (100, 306, 406) according to claim 6, characterised in that the second conductor element (106, 320, 420) is arranged on an other side of the buckling middle portion opposite the first conductor element (104, 318, 418), such that deformation of the second conductor element (106, 320, 420) applies a transverse mechanical force of a second direction, to configure the bistable structure (102) in the first stable position (110); said second direction substantially opposite that of the first direction.
8. The actuator device (100, 306, 406) according to any one of claims 5 to 7, wherein each of the first conductor element (104, 318, 418) and second conductor element (106, 320, 420) comprises a length of wire that is configured to straighten in response to an electrical current passing therethrough.
9. The actuator device (100, 306, 406) according to any one of the preceding claims, characterised in that in the second conductor element (106, 320, 420) is further configured to provide haptic feedback in response to an external force applied thereon.
10. The actuator device (100, 306, 406) according to claim 9, characterised in that the haptic feedback is in the form of a vibration generated by an electrical current passing through the second conductor element (106, 320, 420).
11. The actuator device (100, 306, 406) according to any one of the preceding claims, characterised in that each of the first conductor element (104, 318, 418) and the second conductor element (106, 320, 420) is formed from a smart memory alloy.
12. The actuator device (100, 306, 406) according to any one of the preceding claims, characterised in that in the electrical current that is passed through the first conductor element (104, 318, 418) for switching the bistable structure (102) from the first stable position (110) to the second stable position (112) and the electrical current that is passed through the second conductor element (106, 320, 420) for switching the bistable structure (102) from the second stable position (112) to the first stable position (110) are transient pulsed electrical currents.
13. The actuator device (100) according to any one of claims 1 to 12, characterised in that in the first stable position (110) of the bistable structure (102), the first conductor element (104) is in a deformed state and the second conductor element (106) is in an undeformed state; and in the second stable position (112) of the bistable structure (102), the first conductor element (104) is in an undeformed state and the second conductor element (106) is in a deformed state.
14. The actuator device (100, 306, 406), according to any one of claims 10 to 13, characterised in that the electrical current passing through the second conductor element (106, 320, 420) for providing haptic feedback has an amplitude of from 5 mA 25 to 999 mA.
15. The actuator device (100, 306, 406) according to any one of claims 1 to 14, characterised in that the electrical current for deforming the first and second conductor elements (104, 318, 418) (106, 320, 420) has an amplitude of from 5 A to 30 99A.
16. A system (300, 400) for providing a morphable surface, the system (300, 400) comprising, a sheet layer (200, 302, 402) comprising a first surface (202, 304, 404) and a second surface (204, 424) disposed opposite to the first surface (202, 304, 404); and at least one actuator device (100, 306, 406) according to any one of claims 1 to 15 coupled to the second surface (204, 424) of the sheet layer (200, 302, 402), characterised in that the actuator device (100, 306, 406) is configured to deform the sheet layer (200, 302, 402) at a location corresponding to the bistable structure (102) of the actuator device (100, 306, 406), such that an external protrusion (206, 422) is formed on the first surface (202, 304, 404) of the sheet layer (200, 302, 402) when the bistable structure (102) switches from the first stable position (110) to the second stable position (112).
17. The system (300, 400) according to claim 16, characterised in that the first surface (202, 304, 404) of the sheet layer (200, 302, 402) is substantially flat and devoid of the external protrusion (206, 422) at the location corresponding to the bistable structure (102) of the actuator device (100, 306, 406) when the bistable structure (102) is in the first stable position (110).
18. The system (300, 400) according to claim 16 or 17, characterised in that the sheet layer (200, 302, 402) is made from a substantially pliable material such the sheet layer (200, 302, 402) is configured to be deformable in response to a change in the stable position of the bistable structure (102).
19. A method of making an actuator device (100), the method comprising, providing a bistable structure (102) that is configurable into a first stable position (110) and a second stable position (112); providing a first conductor element (104) and a second conductor element (106) that are capable of deformation when electrical current passes through either of the first and second conductor elements (104, 106); and arranging the first conductor element (104) and the second conductor element (106) to engage with the bistable structure (102), such that the deformation of the first or second conductor elements (104, 106) configures the bistable structure (102) into the first stable position (110) or the second stable position (112).