GB2572422A

GB2572422A - Apparatus and methods for assembling an actuating module

Info

Publication number: GB2572422A
Application number: GB1805219.1A
Authority: GB
Inventors: Eddington Robin; Cottney Aaron; Howarth James; matthew bunting Stephen; Farmer Geoffrey
Original assignee: Cambridge Mechatronics Ltd
Current assignee: Cambridge Mechatronics Ltd
Priority date: 2018-03-29
Filing date: 2018-03-29
Publication date: 2019-10-02
Anticipated expiration: 2038-03-29
Also published as: GB2572422B; GB201805219D0

Abstract

An apparatus 100 for assembling an SMA actuator module e.g. for a miniature camera comprises a holder for holding a component of the actuator module, an alignment module 106 for guiding the SMA wire into a crimp on the actuator module, and a crimping module for closing the crimp. The apparatus may also have an insulation removal module 102, which may use a laser(s) 400 to remove the insulation. The apparatus may be manually-operated, or partly or fully automated. The apparatus may include a slack addition module 108 to add a controlled amount of slack into the SMA actuator wire

Description

FIGURE 10

Apparatus and Methods for Assembling an Actuating Module

The present application generally relates to apparatus and methods for coupling shape memory alloy (SMA) actuator wires to an actuator or actuating component, and in particular to a tool for manufacturing or assembling parts of an actuating module.

There are many types of apparatus in which it is desirable to provide positional control of a movable element. SMA actuator wire is advantageous as an actuator (or part of an actuator/actuating component) because of its high energy density, which means that an actuator comprising SMA actuator wire that is required to apply a particular force can be of a relatively small size.

An example type of apparatus for which SMA actuator wire is used to provide positional control of a movable element is a camera. For example, to achieve focussing, zooming, or shake correction, an actuating component may be used to drive movement of a camera lens element along the optical axis of the camera and/or in a plane orthogonal to the optical axis. In miniature cameras, such as those provided within smartphones, the camera lens element is small and therefore, the actuating component may need to be compact (particularly given space restrictions within smartphones). Consequently, the actuating component must be capable of providing precise actuation over a correspondingly small range of movement. Actuating components that comprise SMA actuator wires may be used to drive movement of such camera lens components. Due to the small size of the moveable element, and the high precision actuation required, the SMA actuator wires may need to be coupled to the actuating component carefully and precisely.

In a first approach of the present techniques, there is provided an apparatus for assembling an actuating module comprising at least one shape memory alloy (SMA) actuator wire, the apparatus comprising: a holder for holding a component of the actuating module to which an SMA actuator wire is to be coupled, the component comprising at least one crimp; an alignment module for guiding the SMA actuator wire into the crimp; and a crimping module for closing the crimp to couple the SMA actuator wire to the component.

In a second approach of the present techniques, there is provided a method for assembling an actuating module comprising at least one shape memory alloy (SMA) actuator wire, the method comprising: providing, in a holder, a component of the actuating module to which an SMA actuator wire is to be coupled, the component comprising at least a first crimp and a second crimp; guiding, using an alignment module, a first portion of the SMA actuator wire into the first crimp; guiding, using the alignment module, a second portion of the SMA actuator wire into the second crimp; and closing, using a crimping module, the first crimp to couple the first portion of the SMA actuator wire to the component, and the second crimp to couple the second portion of the SMA actuator wire to the component.

The present techniques also provide a non-transitory data carrier carrying processor control code to implement any of the methods or processes described herein.

Implementations of the present techniques will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 shows a block diagram of an apparatus for assembling an actuating module comprising at least one shape memory alloy (SMA) actuator wire;

Figure 2 shows a side view of an apparatus for assembling an actuating module comprising at least one SMA actuator wire;

Figure 3 shows a plan view of the apparatus of Figure 2;

Figure 4 shows a side view of an insulation removal module of the apparatus of Figure 2;

Figure 5 shows a side view of a crimping module of the apparatus of Figure 2;

Figure 6 shows a side view along the axis of the SMA actuator wire of the crimping module of Figure 5;

Figure 7 shows a close-up perspective view of components of the crimping module of Figure 5;

Figure 8 shows a flow chart of example steps to assemble an actuating module comprising at least one SMA actuator wire;

Figure 9a shows a schematic cross-sectional view of a camera apparatus comprising an actuating module with at least one SMA actuator wire;

Figure 9b is a plan view of the camera apparatus of Figure 9a showing an arrangement of SMA actuator wires; and

Figure 10 is a close-up perspective view of components of the alignment module of Figure 5.

Broadly speaking, embodiments of the present techniques provide apparatuses and methods for accurate positioning and coupling of a shape memory alloy (SMA) actuator wire to an actuator or actuating component. The apparatus may be manually-operated (i.e. by a human user), partly manuallyoperated and partly automated, or fully automated.

Merely to assist understanding of how SMA actuator wires may be used to provide precise actuation of a moveable element, an example of an actuating module that uses SMA actuator wires is now described. Figure 9a shows a schematic cross-sectional view of a camera apparatus 1 comprising an actuating module with at least one SMA actuator wire, and Figure 9b is a plan view of the camera apparatus of Figure 9a showing an arrangement of SMA actuator wires. The view in Figure 9a is a cross-sectional view taken along optical axis 0, which is a notional, primary axis. The camera apparatus 1 may be incorporated into a portable electronic device such as smartphone or tablet computer. The camera apparatus 1 comprises a lens element 2 supported on a support structure 4 by a suspension system 7, in a manner which allows movement of the lens element 2 relative to the support structure 4 in two orthogonal directions, each perpendicular to the optical axis 0. Thus, in this example, the lens element 2 is a movable element.

The support structure 4 is a camera support supporting an image sensor 6 on the front side of the base 5 thereof. On the rear side of the base 5, other components may be provided, such as an integrated circuit chip 30 or a gyroscope sensor 47. The lens element 2 comprises a lens carrier 21 in the form of a cylindrical body supporting a lens 22 arranged along the optical axis 0, although in general any number of lenses 22 may be provided. In embodiments, the camera apparatus 1 may be a miniature camera in which the lens 22 (or lenses 22 if plural lenses are provided) has a diameter of up to 10mm. The lens element 2 is arranged to focus an image onto the image sensor 6. The image sensor 6 captures the image and may be of any suitable type, for example a CCD (chargecoupled device) or a CMOS (complementary metal-oxide-semiconductor) device.

The or each lens 22 may be fixed relative to the lens carrier 21, or alternatively may be supported on the lens carrier in a manner in which the or each lens 22 is movable along the optical axis O, for example to provide focussing. Where the lens 22 is movable along the optical axis 0, a suitable actuation system (not shown) may be provided, for example using a voice coil motor or SMA actuator wires.

In operation, the lens element 2 is moved orthogonally to the optical axis 0 in two orthogonal directions, shown as X and Y relative to the image sensor 6, with the effect that the image on the image sensor 6 is moved. This is used to provide optical image stabilisation (OIS), compensating for image movement of the camera apparatus 1, caused by, for example, the shaking of a user's hand while operating the camera (or device containing the camera apparatus 1).

The suspension system 7 may comprise four beams 71 connected between a support plate 72 that forms part of the support structure 4 and a lens plate 73 that forms part of the lens element 2 and is connected to the rear end of the lens carrier 21, as shown in Figure 9a. The four beams 71 extend parallel to each other and to the optical axis 0, and therefore extend perpendicular to the orthogonal directions in which the lens element 2 moves, although they could extend at a non-perpendicular angle, provided that they are transverse to the orthogonal directions.

The beams 71 are fixed to each of the support plate 72 and the lens plate 73 in a manner that the four beams 71 cannot rotate, for example by being soldered. The beams 71 are positioned inside the support structure 4 and outside the lens carrier 21, the support plate 72 and the lens plate 73 having the same construction including respective apertures 74 and 75 aligned with the optical axis 0 to accommodate the lens element 2 and allow the passage of light to the image sensor 6. The beams 71 are equally spaced around the optical axis 0, one at each corner of the camera apparatus 1.

The beams 71 thereby support the lens element 2 on the support structure 4 in said manner allowing movement of the lens element 2 relative to the support structure 4 in two orthogonal directions perpendicular to the optical axis 0 simply by means of the beams 71 bending, in particular in an S-shape. Conversely, the beams 71 resist movement along the optical axis 0. The beams 71 may have any construction that provides the desired compliance perpendicular to the optical axis 0, typically being formed by wires, for example metal wires.

In general, the suspension system 7 could have any alternative construction that allows movement of the lens element 2 relative to the support structure 4 in two orthogonal directions perpendicular to the optical axis 0. For example, the suspension system 7 could employ ball bearings or flexures.

An example actuator arrangement 10 is shown in Figure 9b. The actuator arrangement 10 may comprise a total of four SMA actuator wires 11 to 14 connected between a support block 16 that forms part of the support structure 4 and is mounted to the base 5 and a movable platform 15 that forms part of the lens element 2 and is mounted to the rear of the lens plate 73 as shown in Figure 9a.

Each of the SMA actuator wires 11 to 14 is held in tension, thereby applying a force between the movable platform 15 and the support block 16 in a direction perpendicular to the optical axis 0. In operation, the SMA actuator wires 11 to 14 move the lens element 2 relative to the support block 16 in two orthogonal directions perpendicular to the optical axis 0, as described further below.

The SMA actuator wires 11 to 14 extend perpendicular to the optical axis 0. In this actuator arrangement 10, the SMA actuator wires 11 to 14 extend in a common plane which is advantageous in minimising the size of the actuator arrangement 10 along the optical axis 0. This arrangement also minimises the force on the suspension system 7 in a direction parallel to the optical axis 0.

Alternatively, the SMA actuator wires 11 to 14 may be arranged inclined at a non-zero angle to the orthogonal directions perpendicular to the optical axis 0, which angle is preferably small. In this case, the SMA actuator wires 11 to 14 in operation generate a component of force along the optical axis 0 that may tend to tilt or to move the lens element 2 in a direction parallel to the optical axis 0. Such a component of force may be resisted by the suspension system 7 to provide movement in the orthogonal directions perpendicular to the optical axis 0. Conversely, the degree of inclination of the SMA actuator wires 11 to 14 that provides acceptably small tilting or movement in a direction along the optical axis 0 is dependent on the stiffness of the suspension system 7 along the optical axis 0. Thus, relatively high inclinations are permissible in the case ofthe suspension system 7 having a high stiffness along the optical axis 0, for example when comprising the beams 71 as described above or comprising ball bearings.

In the case where the suspension 7 comprises ball bearings, it may even be desirable for the SMA actuator wires 11 to 14 to be inclined with a significant component in a direction parallel to the optical axis 0 such that the tension in the SMA actuator wires 11 to 14 pushes the lens element 2 onto the ball bearings.

Irrespective of whether the SMA wires 11 to 14 are perpendicular to the optical axis 0 or inclined at a small angle to the plane perpendicular to the optical axis 0, the actuator arrangement 10 can be made very compact, particularly in the direction along the optical axis 0. The SMA actuator wires 11 to 14 are themselves very thin, typically of the order of 25pm in diameter, to ensure rapid heating and cooling. The arrangement 10 of SMA actuator wires 11 to 14 barely adds to the footprint of the actuator arrangement 10 and may be made very thin in the direction along the optical axis 0, since the SMA actuator wires 11 to 14 are laid essentially in a plane perpendicular to the optical axis 0 in which they remain in operation. The height along the optical axis then depends on the thickness of the other components such as crimping members 17 and 18 described below and the height necessary to allow manufacture. In practice, it has been found that the actuator arrangement of SMA actuator wires 11 to 14 shown in Figure 9b may be manufactured to a height of less than 1mm.

The SMA actuator wires 11 to 14 are connected at one end to the movable platform 15 by respective crimping members 17 and at the other end to the support block 16 by crimping members 18. The crimping members 17 and 18 crimp the wire to hold it mechanically, optionally strengthened by the use of adhesive. The crimping members 17 and 18 also provide an electrical connection to the SMA actuator wires 11 to 14. However, any other suitable means for connecting the SMA actuator wires 11 to 14 may alternatively be used.

As shown in Figure 9b, the SMA actuator wires 11 to 14 have an arrangement around the optical axis O as follows. Each of the SMA actuator wires 11 to 14 is arranged along one side of the lens element 2. Thus, the SMA actuator wires 11 to 14 are arranged in a loop at different angular positions around the optical axis 0. Thus, the four SMA actuator wires 11 to 14 consist of a first pair of SMA actuator wires 11 and 13 arranged on opposite sides of the optical axis and a second pair of SMA actuator wires 12 and 14 arranged on opposite sides of the optical axis 0. The first pair of SMA actuator wires 11 and 13 are capable on selective driving to move the lens element 2 relative to the support structure 4 in a first direction in said plane, and the second pair of SMA actuator wires 12 and 14 are capable on selective driving to move the lens element 2 relative to the support structure 4 in a second direction in said plane transverse to the first direction. Movement in directions other than parallel to the SMA actuator wires 11 to 14 may be driven by a combination of actuation of these pairs of the SMA actuator wires 11 to 14 to provide a linear combination of movement in the transverse directions. Another way to view this movement is that simultaneous contraction of any pair of the SMA actuator wires 11 to 14 that are adjacent each other in the loop will drive movement of the lens element 2 in a direction bisecting those two of the SMA actuator wires 11 to 14 (diagonally in Figure 9b, as labelled by the arrows X and Y).

As a result, the SMA actuator wires 11 to 14 are capable of being selectively driven to move the lens element 2 relative to the support structure 4 to any position in a range of movement in two orthogonal directions perpendicular to the optical axis 0. The magnitude of the range of movement depends on the geometry and the range of contraction of the SMA actuator wires 11 to 14 within their normal operating parameters.

The position of the lens element 2 relative to the support structure 4 perpendicular to the optical axis 0 is controlled by selectively varying the temperature of the SMA actuator wires 11 to 14. This is achieved by passing through SMA actuator wires 11 to 14 selective drive currents that provides resistive heating. Heating is provided directly by the drive current. Cooling is provided by reducing or ceasing the drive current to allow the lens element 2 to cool by conduction, convection and radiation to its surroundings.

As will be understood by a person of skill in the art, assembling the example SMA actuation apparatus shown in Figures 9a and 9b may be difficult, because of the small size of the actuation apparatus, and the precise arrangement of the SMA wires. Accordingly, the present techniques provide a precision manufacturing tool and process for assembling an SMA actuation apparatus.

Turning to Figure 1, this shows a block diagram of an apparatus 100 for assembling an actuating module comprising at least one shape memory alloy (SMA) actuator wire. The apparatus 100 may enable accurate positioning and coupling of a shape memory alloy (SMA) actuator wire to an actuator or actuating component. The apparatus 100 may be manually-operated, partly manuallyoperated and partly automated, or fully automated.

Generally speaking, the actuating module comprises a component to which an SMA actuator wire is to be coupled. The actuating module may comprise: a support structure, for example, for supporting a moveable component; a moveable platform; an integrated circuit chip or processor for controlling the movement of the actuating module; the moveable element; etc. The term component to which an SMA actuator wire is to be coupled is used herein to mean any component of the actuator module to which the SMA wire is to be coupled. The term is used herein to mean that both ends of the SMA actuator wire may be coupled to the same component of the actuator module, or that each end of the SMA actuator wire may be coupled to different components of the actuator module. The term is also used to cover the possibility that both ends of the SMA wire are coupled to a fret having crimps, where the fret is coupled to the actuating module.

The apparatus 100 may comprise an alignment module 106 for guiding an SMA actuator wire into position such that it can be coupled to the correct part of the actuator or actuating component. Each end of a length of SMA actuator wire is coupled to different points on the actuator/actuating component, as shown in the example of Figures 9a and 9b. Accordingly, the alignment module 106 may guide an SMA actuator wire such that a portion of the SMA actuator wire is guided towards and positioned at one coupling site on the actuator, and another portion of the SMA actuator wire is guided towards and positioned at another coupling site on the actuator. In embodiments, each end of an SMA actuator wire may be coupled to the actuator via a crimp or crimping element, which securely fastens the end of the SMA actuator wire to the actuator, while also ensuring a mechanical and electrical connection is made between the SMA actuator wire and the actuator. Thus, the alignment module 106 may guide the SMA actuator wire towards a crimp, which is provided at a coupling site on the actuator. The alignment module 106 may be arranged to ensure the SMA actuator wire is held under tension while being coupled to the actuator.

In embodiments, the alignment module 106 may pull an end of SMA actuator wire from a spool of wire (or similar), and guide the SMA actuator wire such that at least one portion of the SMA actuator wire is provided within a crimp ofthe actuator. In embodiments, the alignment module 106 may guide the SMA actuator wire such that a first portion of the SMA actuator wire is guided towards and provided within a first crimp of the actuator, and a second portion of the SMA actuator wire is guided towards and provided within a second crimp of the actuator. After the SMA actuator wire has been coupled to the first and second crimps, the wire may be cut and thereby detached from the remaining wire on the spool.

The apparatus may comprise a crimping module 104 to close each crimp/crimping element after the SMA actuator wire is positioned in the crimp. The crimping module 104 may comprise any suitable mechanism to close each crimp. The crimping module 104 may comprise components which are aligned with the coupling sites/location of the crimps on the actuator, such that when the crimping process takes place, the components are in the correct position to close the crimps without touching (and thereby, potentially damaging) any other parts of the actuator.

Thus, the present techniques provide an apparatus or tool 100 for assembling an actuating module comprising at least one shape memory alloy (SMA) actuator wire, where the apparatus may comprise: a holder for holding a component of the actuating module to which an SMA actuator wire is to be coupled, the component comprising at least one crimp; an alignment module 106 for guiding the SMA actuator wire into the crimp; and a crimping module 104 for closing the crimp to couple the SMA actuator wire to the component. The crimping module 104 and the alignment module 106 may each be caused to operate manually, or one or both of the modules may be automated. It will be understood that the crimping operation only takes place once the SMA actuator wire has been guided into the correct position.

As mentioned above, SMA actuator wires are often used to move small components, such as a lens in a miniature camera of a smartphone. As the components of an actuator may need to be as small as possible, this may result in the SMA actuator wire being located very close to other components of the actuator, camera or smartphone, especially metallic components. If the SMA actuator wire comes into contact with a metal surface that is at a different potential to the SMA actuator wire, then a short circuit may occur. This can cause local heating on the surface of the wire, which can lead to melting and damage of the SMA wire. The SMA wire may become weakened, which may lead to reduced performance or fractures that cause breakage of the wire. Accordingly, it may be desirable to coat or wrap a core of SMA material with a layer of electrically insulating material, to provide an SMA actuator wire that is sufficiently electrically and thermally insulated. In embodiments, the SMA actuator wire may be formed of a core of SMA material that is coated with an electrically insulating layer. The insulating layer may have a thickness in the range of 0.3pm to 10pm.

The SMA actuator wire may be formed such that the electrically insulating layer is provided along the entire length of the core SMA material. However, achieving good mechanical and electrical contact between the SMA actuator wire and the crimps of the actuator may be hindered by the presence of a relatively thick layer (e.g. of the order of lpm or more) of electrically insulating material. The mechanical action of closing the jaws of the crimp during assembly may not be sufficient to break the electrically insulating layer and thereby, make good contact with the core of SMA material beneath. Thus, in embodiments, the apparatus /tool 100 may comprise an insulation removal module 102, for selectively removing at least one portion of an electrically insulating coating or layer of the SMA actuator wire. The insulation removal module may be arranged to remove portions of the electrically insulating coating of an SMA actuator wire, and in particular, remove portions of the electrically insulating coating corresponding to the portions of SMA actuator wire that are to be coupled to the actuator. The electrically insulating coating may be selectively removed using any suitable technique, such as mechanical abrasion, chemical removal, laser or plasma ablation, or melting of the coating by heating (e.g. using a laser).

Typically, during the assembly process to couple an SMA actuator wire to an actuator, the SMA actuator wire is provided from a spool of wire of known tension. The spools of wire may comprise wire stretched to a known tension, sufficient to prevent further stretching during handling. This also means that once the wire is coupled to the actuator (e.g. via crimps), the wire is taut, as required for controllable actuator operation. However, it may be useful to deliberately add some slack to the SMA actuator wire before it is coupled to the actuator, such that once the wire is coupled to the actuator, the SMA wire is slack rather than taut. It has been found that such slack wires may provide a greater actuator stroke than that of a similar actuator made with taut wires. This is because a longer SMA wire provides greater stroke, so using a longer wire may generally be advantageous, and because the wire from the spool is already under tension, such that it is difficult to stretch the wire any further during operation of the actuator. Thus, in embodiments, the apparatus/ tool 100 may comprise a slack addition module 108. The slack addition module 108 may be arranged to provide a specific, controllable amount of slack or additional length of actuator wire between the coupling sites/crimps.

Various modules and components of the apparatus 100 are now described in more detail with reference to Figures 2 to 7.

Figure 2 shows a side view of an example apparatus 100 for assembling an actuating module comprising at least one SMA actuator wire, and Figure 3 shows a plan view of the apparatus 100 of Figure 2. As mentioned above, apparatus 100 may enable accurate positioning and coupling of a shape memory alloy (SMA) actuator wire to an actuator or actuating component. The apparatus 100 may be manually-operated, partly manually-operated and partly automated, or fully automated. The example apparatus 100 shown in Figure 2 may be considered to comprise two parts or segments, as indicated by the dashed boxes. The segment on the left hand side of the apparatus 100 as shown in Figure 2 may comprise an insulation removal module 102, while the segment on the right hand side may comprise a crimping module 104. The segment of the apparatus 100 on the right hand side may also comprise an alignment module 106 and/or a slack addition module 108.

Figure 4 shows a side view of the insulation removal module 102 of the apparatus 100 of Figure 2. As mentioned above, the SMA actuator wire used to provide or assemble an actuating module may be formed of a wire having a core of SMA material that is coated with an electrically insulating layer. The insulating layer may have a thickness in the range of 0.3pm to 10pm. The SMA actuator wire may be formed such that the electrically insulating layer is provided along the entire length of the core SMA material. As mentioned earlier, to enable a good mechanical and electrical connection between the SMA actuator wire and the component(s) of the actuating module to which the SMA actuator wire is to be coupled, it may be useful to remove portions of the electrically insulating coating. Specifically, it may be useful to selectively remove all or part of the electrically insulating coating at the point(s) on the wire which will be coupled to the component(s) of the actuating module. For example, if a length of SMA actuator wire is to be coupled to two crimps, which are a fixed, known distance apart, then the insulation removal module 102 may be arranged to remove (all or part of) the electrically insulating coating from two points on the SMA actuator wire, where the two points are separated by substantially the same distance as the distance between the two crimps. Accordingly, when the electrically insulating coating has been removed from two points on an SMA actuator wire, the alignment module 106 of the apparatus 100 may guide the SMA actuator wire such that the two points are aligned with the two components of the actuating module to which the SMA actuator wire is to be coupled (e.g. the two crimps).

It will be understood that the separation of the two points on the SMA actuator wire where the insulating coating is (partly or completely) removed may depend on, for example, the precise arrangement of the actuator wire, the structure of the actuating module, and/or whether any slack is to be added to the wire. It is important to ensure that a precise length of SMA wire is provided between the crimping elements 17 and 18. In embodiments, a single piece of SMA wire may be provided between each pair of crimping elements 17 and 18. Here, the length of SMA wire needs to be at least the same as the distance DO between a pair of crimping elements 17 and 18, as shown in Figure 9b. In embodiments where slack is added to an SMA wire before it is coupled to the crimping elements 17 and 18, the length of SMA wire provided between the crimping elements may need to be substantially equal to the distance DO plus a fixed amount (predetermined/predefined amount) of slack length. In embodiments, each SMA wire may have a V-shape, where it is connected at its ends to two crimps and hooked over or around another connector at its midpoint. For example, if neighbouring elements 17 in Figure 9b were actually used to position an SMA wire in a V-shape (and not to crimp), then the length of SMA wire provided between crimping elements 18, and hooked around elements 17, would need to be at least the same as the distance DI, i.e. the distance from a first crimping element 18 to hooking elements 17 and on to a second crimping element 18, as shown in Figure 9b. Again, if slack is to be added, then the length of SMA wire provided between the crimping elements 18 may need to be substantially equal to the distance DI plus a fixed amount of slack length.

The insulation removal module 102 may be arranged to remove (all or part of) the electrically insulating coating at a particular point along an SMA actuator wire, by using any suitable technique, such as mechanical abrasion, chemical removal, laser or plasma ablation, or by melting the coating (e.g. using a laser). To achieve a good mechanical and electrical connection, it may not be necessary to completely remove all of the electrically insulating coating.

In the embodiment shown in Figure 4, the insulation removal module 102 comprises two lasers 400, and a component 404 for holding an SMA actuator wire 402 in position during the insulation removal process. The two lasers 400 may be used to remove (all or part of) the electrically insulating coating at two points along the SMA actuator wire 402. The two lasers 400 may simultaneously emit a laser beam to remove all or part of the electrically insulating coating, or each laser may be operated in turn. Preferably, the two lasers 400 are of the same type (e.g. the same power and wavelength), so that two lasers 400 remove the electrically insulating coating in the same manner. The two lasers 400 may be used to ablate the electrically insulating coating off the core SMA material at the two points along the SMA actuator wire 402. Alternatively, the two lasers 400 may be used to melt all or part of the electrically insulating coating off the core SMA actuator material at the two points along the SMA actuator wire 402. The melting may disperse or displace enough of the electrically insulating coating such that a good electrical connection to the core SMA material is possible. The two lasers 400 may be positioned such that the two laser beams are directed to two points on the SMA actuator wire 402 that are separated by the same distance as the distance between the two crimps to which the SMA actuator wire 402 is to be coupled. Optical elements may be used to adjust the path of one or both laser beams to enable the correct positioning of the beams relative to the SMA actuator wire 402.

It will be understood that the insulation removal module 102 could, in embodiments, comprise a single laser instead of two lasers 400. A laser beam from the single laser could be split into two beams, preferably of the same or substantially the same power. Thus, in embodiments, the insulation removal module 102 may comprise a beam splitter to provide the two beams. The insulation removal module 102 may further comprise optical elements to direct each beam to the correct positions along the SMA actuator wire 402 as the wire is held in position by component 404.

In the two laser and single laser embodiments described above, the SMA actuator wire 402 is held in place by component 404 during the insulation removal process, and then may be pulled out of component 404 and guided towards the crimps by the alignment module 106. Alternatively, the insulation removal module 102 may comprise a single laser and a means for moving the SMA actuator wire 402 relative to a laser beam of the single laser. In this way, a single laser and a single beam could be used to remove the insulating coating from the SMA actuator wire 402. In this embodiment, the laser may be turned on to remove the insulating coating from a first point along the SMA actuator wire 402, and then may be turned off (or the beam may be blocked by a shutter or otherwise) while the SMA actuator wire 402 is moved such that a second point will be in the beam path when the laser is turned back on (or the shutter opened), where the first point and second point are separated by a distance substantially equal to the distance between the two crimps to which the SMA actuator wire 402 is to be coupled. The laser may be turned on (or the shutter opened) to remove the insulating coating from the second point, and then turned off/blocked.

Thus, in embodiments, the apparatus 100 may comprise an insulation removal module 102 for selectively removing at least one portion of an electrically insulating coating around the SMA actuator wire 402. The insulation removal module may comprising a laser for selectively removing at least some of the at least one portion of the electrically insulating coating. As mentioned above, it may be sufficient to remove at least some of the insulating coating to achieve a good electrical and mechanical connection between the SMA actuator wire and the actuating module. At least some ofthe insulating coating may be removed if heat (e.g. provided by the laser) is used to melt the insulating coating, while substantially all of the insulating coating may be remove if laser ablation is employed. Thus, the laser may selectively remove at least some of the at least one portion of the electrically insulating coating by one of laser ablation or melting of the electrically insulating coating.

A first portion of the SMA actuator wire may be couplable to a first crimp, and a second portion of the SMA actuator wire may be couplable to a second crimp, where the first crimp and second crimp are separated by a fixed distance, and where the insulation removal module 102 may be configured to selectively remove some or all of the electrically insulating coating at the first portion and the second portion of the SMA actuator wire. The first portion and the second portion may be separated by a length of SMA actuator wire that is at least the same length as the fixed distance between the first and second crimps.

The insulation removal module 102 may comprise a stage for positioning the SMA actuator wire relative to the laser, such that a beam emitted by the laser is directed to the first portion of the SMA actuator wire. The insulation removal module may comprise movement means for moving the stage by a distance equal to the fixed distance, such that the beam emitted by the laser is directed to the second portion of the SMA actuator wire. While the movement occurs, the laser may be switched off or may be blocked. The stage may be a translation stage and the movement means may be a micrometer adjuster. The micrometer adjuster may be manual or motorised. For example, the micrometer adjuster may be automatically controlled to move the translation stage after the electrically insulative coating has been removed from the first portion, or a duration of time has elapsed which is determined to be sufficient to remove the coating.

Alternatively, the insulation removal module 102 may comprise a first laser beam for selectively removing at least some of a first portion of the electrically insulating coating of the SMA actuator wire 402, and a second laser beam for selectively removing at least some of a second portion of the electrically insulating coating of the SMA actuator wire 402. The first laser beam and second laser beam may be provided by, respectively, a first laser and a second laser, or may be provided by a single laser beam from a single laser that is split into two or more beams. Here, the first portion of the SMA actuator wire may be couplable to a first crimp, and the second portion of the SMA actuator wire may be couplable to a second crimp, where the first crimp and second crimp may be separated by a fixed distance, and where the first portion and the second portion are separated by a length of SMA actuator wire that is at least the same length as the fixed distance between the first and second crimps.

Alternatively, the insulation removal module 102 may comprise a laser and one or more optical elements arranged to split a beam emitted by the laser into a first laser beam and a second laser beam, and to direct the first and second laser beams towards, respectively, a first portion and a second portion of the SMA actuator wire.

The insulation removal module 102 may, for safety reasons, be contained within a container or box 410. This may be particularly important where one or more lasers are used to perform the insulation removal process. The container 410 may comprise a door 406 (with a handle 408), to allow access to the wire 402 and lasers 400, and to prevent access for safety reasons when the lasers are in operation (for example).

In embodiments where the apparatus 100 comprises an insulation removal module 102, the prepared SMA actuator wire 402 is pulled out of the insulation removal module 102 and towards the crimps to which the SMA actuator wire 402 is to be coupled, by the alignment module 106. However, it will be understood that in some embodiments, the SMA actuator wire 402 may be prepared elsewhere or may be received ready-prepared/ready-to-use, and in this case, the alignment module 106 may pull the SMA actuator wire 402 from a spool or from another source/location. For example, in embodiments, the electrically insulating coating may be selectively applied to the core SMA material, such that selective removal is not required. In this case, the insulation removal module 102 may not be required.

However the SMA actuator wire 402 is prepared, the alignment module 106 is used to direct the SMA actuator wire 402 to the coupling sites on the actuating module. Figure 5 shows a side view of a crimping module 104 and an alignment module 106 of the apparatus of Figure 2, viewed along an axis perpendicular to the axis of the SMA actuator wire 402. The crimping module 104 and alignment module 106 may be provided as part of a die tool set. The die tool set comprises a die tool top 514 and a die tool base 516. Components of the crimping module 104 and alignment module 106 may be coupled to the die tool top 514 and/or the die tool base 516. The die tool base 516 may be static, while the die tool top 514 may be moveable. The die tool set may comprise a handle or lever 500 for moving the die tool top 514. Moving the lever 500 (in the directions indicated by arrow A) may cause the die tool top 514 to move in the directions indicated by arrow B. Thus, the die tool top 514 can be moved closer to the die tool base 516 by operation of lever 500.

The alignment module 106 may be capable of moving in three dimensions in order to accurately guide an SMA actuator wire into the crimp(s). The alignment module may be capable of moving in the x direction (i.e. parallel to the axis of SMA wire 402), so that the alignment module can pick up an end of the SMA wire and pull the wire 402 towards the crimps, and so that the alignment module can move to a 'start' position when a new component of the actuating module is being provided in the tool, or a current component to which the SMA wire has been coupled is being removed. The alignment module 106 may be capable of moving in the y direction (i.e. perpendicular to the axis of the SMA wire 402, or in an updown direction), so that the alignment module can raise and lower the SMA actuator wire 402 as it is being moved towards the crimps. The alignment module 106 may be capable of moving in the z direction (i.e. perpendicular to the axis of the SMA wire 402, or in a side-to-side direction), so that the alignment module can push an SMA wire 402 into a crease or fold of the crimps (as explained in more detail below). The movements of the alignment module 106 in each dimension are carefully controlled to enable the SMA wire 402 to be positioned accurately.

The alignment module 106 may comprise a gripper 504 for gripping an end of the prepared SMA actuator wire 402, and a guide plate 502 for moving the gripper 504 between a number of defined positions. As shown in Figure 10, which shows a close-up of the alignment module 106, the guide plate 502 may comprise three notches or grooves A, B and C, which define three positions. The alignment module may comprise a pin or handle which is provided within the guide plate 502 (as shown in Figure 10), such that movement of the pin/handle in the guide plate effects movement of the alignment module 106 (and specifically the gripper 504), in a defined manner. When a new component of the actuating module is being inserted into holder 612, the alignment module 106 may need to be moved out of the way, to enable the actuating module to be carefully placed in the holder.

Similarly, when a component of an actuating module to which a SMA wire has been coupled needs to be moved/turned (so that another SMA wire may be coupled to another side of the component), or when the component needs to be removed from the holder, the alignment module 106 may need to be moved out of the way. Accordingly, the guide plate 502 may comprise notch A which defines a 'start' position or'safety' position. When the pin/handle of the alignment module 106 is placed in notch A, the alignment module 106 is positioned away from the holder 612 as shown in Figure 10.

Guide plate 502 may comprise notch B which defines a first position. The first position is, referring to Figure 10, to the left of the holder 612 or component, but closer to the holder 612 or component than the 'start' position. When a component is in holder 612 and is ready to be coupled to an SMA wire 402, the pin/handle of the alignment module 106 is placed in notch B such that gripper 504 can pick up an SMA wire 402.

Guide plate 502 may comprise notch C which defines a second position. When the pin/handle of the alignment module 106 is placed in notch C, the gripper 504 moves the wire all the way across the component and into the crimp(s) of the component. The gripper 504 then remains in this position, and therefore keeps the SMA wire 402 at a known tension, while the crimping module 104 couples the SMA wire to the component. When the coupling process is complete, the gripper 504 is operated to release the SMA wire 504, before being moved back to the first position (by moving the pin/handle to notch B). The gripper 504 is able to grip onto SMA wire 402 in this position, before the SMA wire is cut. This ensures an end of SMA wire is within the gripper 504 and ready for coupling to the next component (or a different part of the existing component).

Thus, the guide plate 502 enables movement of the alignment module 106 (and in particular, gripper 504) in two dimensions, i.e. in the x direction as shown in Figure 10, and in a z direction (which extends out of the page).

The alignment module 106 may also be capable of moving in the y direction. This may be useful for ensuring the SMA wire 402 is in the fold/crease of each crimp, where the best coupling occurs when the crimps are closed.

Returning to Figure 5, the component of the actuating module to which the SMA actuator wire 402 is to be coupled may be provided within a holder located on the die tool base 516. Therefore, to ease the guidance and positioning of the SMA actuator wire 402 into the crimps of the component of the actuating module, the gripper 504 may also be provided on the die tool base 516 as shown in Figure

5. When the alignment module 106 has positioned the SMA actuator wire 402 such that the portions of the wire which are not (partly or completely) coated with an electrically insulating layer are aligned with the crimps of the component of the actuating module, the crimping module 104 may be activated. The crimping module 104 may comprise a punch 512 and an anvil (not visible) for closing the crimps of the actuating module once the SMA actuator wire is in position. The punch 512 is provided on the die tool top 514, while the anvil is on the die tool base 516. The punch 512 may be shaped such that it is able to simultaneously close two crimps of the actuating module. Moving the lever 500 causes die tool top 514 to move towards the die tool base 516, such that the punch 512 engages with the crimps, but does not damage or contact any other part of the component or actuating module.

Thus, in embodiments, the alignment module 106 may comprise: a gripper for temporarily holding an end of the SMA actuator wire; and a guide mechanism for moving the gripper towards the at least one crimp of the actuating component.

The die tool set may also comprise a slack addition module 108. The slack addition module 108 may comprise an adjustable wire lifting element 506, for lifting the SMA actuator wire when the SMA actuator wire is positioned within the two crimps, before the crimps are closed by punch 512. The adjustable wire lifting element 506 may comprise a pivotable element (not visible in Figure 5). Pushing down on one part of the pivotable element may cause another part of the pivotable element to lift upwards. A first end of the pivotable element may be provided below the SMA actuator wire, such that when a downward force is applied to a second end of the pivotable element, the first end is forced upwards and lifts the SMA actuator wire to provide slack. The adjustable wire lifting element 506 may comprise an adjustment mechanism, such as a micrometer adjuster, for controlling (and limiting) the amount of movement of the pivotable element to precisely control the amount of slack added to the SMA actuator wire 402. The slack addition module 108 may comprise a handle 508 for moving the adjustable wire lifting element 506 between a first position in which no slack is added, and a second position in which the adjustable wire lifting element 506 adds slack to the SMA actuator wire 402. The adjustable wire lifting element 506 may be moved by handle 508 along a track or guide 518, between the first and second positions. The adjustable wire lifting element 506 and the guide 518 may be provided on the die tool base 516. The slack addition module 108 may comprise a pressing tool 510, provided on the die tool top 514. The pressing tool 510 may be arranged to engage with the second end ofthe pivotable element when the die tool top 514 is lowered towards the die tool base 516, and thereby cause the first end of the pivotable element to add slack to the SMA actuator wire 402.

Thus, in embodiments, the slack addition module 108 may comprise an adjustable lifting element for lifting the SMA actuator wire when the wire is provided between the first and second crimps. The slack addition module may comprise a micrometer adjuster for raising and lowering the adjustable lifting element to provide a required amount of slack.

In embodiments, the apparatus 100 may comprise a cutting tool for cutting the SMA actuator wire after the SMA actuator wire is coupled to the at least one crimp.

In embodiments, the crimping module 104 may comprise a punch and an anvil. The punch and anvil may be shaped. For example, the punch may be dome shaped and the anvil may be cup shaped to correspond to the dome shape of the punch.

Figure 6 shows a side view along the axis of the SMA actuator wire of the die tool set of Figure 5, which more clearly shows some of the above-described features. The apparatus 100 comprises a holder 610 for holding a component of the actuating module to which an SMA actuator wire is to be coupled. The holder 610 may be provided on the die tool base 516. The alignment module 106 may comprise a finger 600, for pushing the SMA actuator wire 402 into the back of each crimp (i.e. into a crease or fold of the crimp) before the crimps are closed.

This may be desirable because the most secure and firm coupling of the SMA actuator wire 402 to the crimp may be provided if the SMA actuator wire is in the crease/fold of the crimp. Accordingly, when the die tool top 514 is lowered towards the die tool base 516, the finger 600 may engage with a mechanism (not visible) that pushes the SMA actuator wire into the back of each crimp. Preferably, this engagement occurs before the punch 512 engages (or fully engages) with and closes the crimps.

As mentioned above, the adjustable wire lifting element 506, for adding slack to the SMA actuator wire before the crimps are closed, may comprise a pivotable element 604, which moves about a pivot 602. A first end of the pivotable element 604 (e.g. the rightmost end in Figure 6) may be provided below the SMA actuator wire 402, such that when a downward force is applied to a second end of the pivotable element 604 (e.g. the leftmost end in Figure 6), the first end is forced upwards and lifts the SMA actuator wire to provide slack. The slack addition module 108 may comprise a handle 508 for moving the adjustable wire lifting element 506 between a first position in which no slack is added, and a second position in which the adjustable wire lifting element 506 adds slack to the SMA actuator wire 402. The adjustable wire lifting element 506 may be moved by handle 508 along track or guide 518, between the first and second positions. The pressing tool 510 may be arranged to engage with the second end of the pivotable element when the die tool top 514 is lowered towards the die tool base 516, and when the adjustable wire lifting element 506 is in the second position (i.e. able to add slack).

As mentioned above, the alignment module 106 may comprise a gripper 504 for gripping an end of the prepared SMA actuator wire 402. The gripper 504 may comprise jaws which may be arranged to open and close by operation of lever 606. The default position of the jaws may be a closed position, or gripping position, such that operation of lever 606 opens the jaws to grip or release an SMA actuator wire 402. The gripper 504 may comprise a cutting tool for cutting the SMA actuator wire after it has been coupled to the actuating module. Lever 608 may be operated to release and position the cutting tool. The cutting tool may be a blade or knife.

Figure 7 shows a close-up perspective view of components of the die tool set of Figure 5. As indicated by arrow C, the adjustable wire lifting element 506 may be moved along track/guide 518, between a first position in which no slack is added, and a second position in which the adjustable wire lifting element 506 adds slack to the SMA actuator wire 402.

The gripper 504 of the alignment module 106 can be seen in more detail in Figure 7. The gripper 504 may comprise jaws 700, 702 between which SMA actuator wire 402 may be gripped. The jaws 700, 702 may be arranged to open and close by operation of lever 606. The default position of the jaws may be a closed position, or gripping position, such that operation of lever 606 opens the jaws to grip or release an SMA actuator wire 402. The gripper 504 may comprise a cutting tool 704 for cutting the SMA actuator wire 402 after it has been coupled to the actuating module. Lever 608 may be operated to release and position the cutting tool 704. The cutting tool may be a blade or knife.

It will be understood that some or all of the processes described above may be performed manually, e.g. by a human operator of apparatus 100, or may be performed automatically, e.g. by a robotic arm or other mechanised and automated process. It will be understood that parts of the die tool set may be moveable in a way to permit access to a human user or robotic arm. For example, the die tool set top 514 may be arranged to lift up by a sufficient distance to allow an actuating module to be placed within the holder 612, so that the SMA actuator wire may be coupled to the actuating module, and to allow the assembled actuating module to be removed. Similarly, it may be possible to automatically move the wire lifting element 506 between the first and second positions, and to automatically move the gripper 504, via the guide plate 502 between the 'start', first and second positions. Accordingly, the present techniques also provide methods for assembling an actuating module comprising at least one SMA actuator wire. Figure 8 shows a flow chart of example steps for assembling an actuating module comprising at least one SMA actuator wire. If the SMA actuator wire to be coupled to the actuating module comprises a core of SMA material surrounded by an electrically insulating coating, portions of the coating may need to be removed to improve the mechanical and electrical connection between the SMA actuator wire and actuating module, as explained above. Thus, in embodiments, the process may begin with selectively removing the electrically insulating coating at a first point (or along a first portion) of the SMA actuator wire and at a second point (or along a second portion) of the SMA actuator wire (step S800). If the SMA actuator wire was selectively coated with electrically insulating coating, or is obtained in a prepared form, then this step may be omitted.

The process may comprise guiding the first portion of the SMA actuator wire into a first crimp (step S802) and the second portion of the SMA actuator wire into a second crimp (step S804). The first and second portions of the SMA actuator wire comprise substantially no insulating coating. As explained above, the distance between the first and second portions is substantially equal to the distance between the first and second crimps.

The process may comprise pushing the first and second portions of the SMA actuator wire into the crease or fold of the first and second crimps, respectively, before the crimps are closed, for the reason described above (step S806).

Optionally, slack may be added to the SMA actuator wire once it is provided between the crimps (step S808), for the reasons described above.

The first and second crimps are then closed (step S810), using a punch and anvil, for example. Once the crimps are closed, a cutting tool may be used to cut the end of the SMA actuator wire which is coupled to a spool or source of the wire (step S812), and the actuating module may now be removed from the assembly apparatus.

In a related approach of the present techniques, there is provided a nontransitory data carrier carrying processor control code to implement any of the processes or methods described herein.

As will be appreciated by one skilled in the art, the present techniques may be embodied as a system, method or computer program product. Accordingly, present techniques may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects.

Furthermore, the present techniques may take the form of a computer program product embodied in a computer readable medium having computer readable program code embodied thereon. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may be, for example, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing.

Computer program code for carrying out operations of the present techniques may be written in any combination of one or more programming languages, including object oriented programming languages and conventional procedural programming languages. Code components may be embodied as procedures, methods or the like, and may comprise sub-components which may take the form of instructions or sequences of instructions at any of the levels of abstraction, from the direct machine instructions of a native instruction set to high-level compiled or interpreted language constructs.

Embodiments of the present techniques also provide a non-transitory data carrier carrying code which, when implemented on a processor, causes the processor to carry out any of the methods described herein.

The techniques further provide processor control code to implement the above-described methods, for example on a general purpose computer system or on a digital signal processor (DSP). The techniques also provide a carrier carrying processor control code to, when running, implement any of the above methods, in particular on a non-transitory data carrier. The code may be provided on a carrier such as a disk, a microprocessor, CD- or DVD-ROM, programmed memory such as non-volatile memory (e.g. Flash) or read-only memory (firmware), or on a data carrier such as an optical or electrical signal carrier. Code (and/or data) to implement embodiments of the techniques described herein may comprise source, object or executable code in a conventional programming language (interpreted or compiled) such as C, or assembly code, code for setting up or controlling an ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array), or code for a hardware description language such as Verilog (RTM) or VHDL (Very high speed integrated circuit Hardware Description Language). As the skilled person will appreciate, such code and/or data may be distributed between a plurality of coupled components in communication with one another. The techniques may comprise a controller which includes a microprocessor, working memory and program memory coupled to one or more of the components of the system.

It will also be clear to one of skill in the art that all or part of a logical method according to embodiments of the present techniques may suitably be embodied in a logic apparatus comprising logic elements to perform the steps of the above-described methods, and that such logic elements may comprise components such as logic gates in, for example a programmable logic array or application-specific integrated circuit. Such a logic arrangement may further be embodied in enabling elements for temporarily or permanently establishing logic structures in such an array or circuit using, for example, a virtual hardware descriptor language, which may be stored and transmitted using fixed or transmittable carrier media.

In an embodiment, the present techniques may be realised in the form of a data carrier having functional data thereon, said functional data comprising functional computer data structures to, when loaded into a computer system or network and operated upon thereby, enable said computer system to perform all the steps ofthe above-described method.

Those skilled in the art will appreciate that while the foregoing has described what is considered to be the best mode and where appropriate other modes of performing present techniques, the present techniques should not be limited to the specific configurations and methods disclosed in this description of the preferred embodiment. Those skilled in the art will recognise that present techniques have a broad range of applications, and that the embodiments may take a wide range of modifications without departing from any inventive concept as defined in the appended claims.

Claims

1. An apparatus for assembling an actuating module comprising at least one shape memory alloy (SMA) actuator wire, the apparatus comprising:

a holder for holding a component of the actuating module to which an SMA actuator wire is to be coupled, the component comprising at least one crimp;

an alignment module for guiding the SMA actuator wire into the crimp; and a crimping module for closing the crimp to couple the SMA actuator wire to the component.

2. The apparatus as claimed in claim 1, the alignment module comprising: a gripper for temporarily holding an end of the SMA actuator wire; and a guide mechanism for moving the gripper towards the at least one crimp.

3. The apparatus as claimed in claim 1 or 2 further comprising an insulation removal module for selectively removing at least one portion of an electrically insulating coating around the SMA actuator wire.

4. The apparatus as claimed in claim 3, the insulation removal module comprising a laser for selectively removing at least some of the at least one portion of the electrically insulating coating.

5. The apparatus as claimed in claim 4 wherein the laser selectively removes at least some of the at least one portion of the electrically insulating coating by one of laser ablation or melting of the electrically insulating coating.

6. The apparatus as claimed in claim 4 or 5, where a first portion of the SMA actuator wire is couplable to a first crimp, and a second portion of the SMA actuator wire is couplable to a second crimp, the first crimp and second crimp separated by a fixed distance, and where the insulation removal module is configured to selectively remove some or all of the electrically insulating coating at the first portion and the second portion of the SMA actuator wire, the first portion and the second portion separated by a length of SMA actuator wire that is at least the same length as the fixed distance between the first and second crimps.

7. The apparatus as claimed in claim 6, the insulation removal module further comprising a stage for positioning the SMA actuator wire relative to the laser, such that a beam emitted by the laser is directed to the first portion of the SMA actuator wire.

8. The apparatus as claimed in claim 7, the insulation removal module comprising movement means for moving the stage by a distance equal to the fixed distance, such that the beam emitted by the laser is directed to the second portion of the SMA actuator wire.

9. The apparatus as claimed in claim 8, where the stage is a translation stage and the movement means is a micrometer adjuster.

10. The apparatus as claimed in claim 9, where the micrometer adjuster is manual or motorised.

11. The apparatus as claimed in claim 3, the insulation removal module comprising a first laser beam for selectively removing at least some of a first portion of the electrically insulating coating of the SMA actuator wire, and a second laser beam for selectively removing at least some of a second portion of the electrically insulating coating of the SMA actuator wire.

12. The apparatus as claimed in claim 11, where the first portion of the SMA actuator wire is couplable to a first crimp, and the second portion of the SMA actuator wire is couplable to a second crimp, the first crimp and second crimp separated by a fixed distance, and where the first portion and the second portion are separated by a length of SMA actuator wire that is at least the same length as the fixed distance between the first and second crimps.

13. The apparatus as claimed in claim 3, the insulation removal module comprising a laser and one or more optical elements arranged to split a beam emitted by the laser into a first laser beam and a second laser beam, and to direct the first and second laser beams towards, respectively, a first portion and a second portion of the SMA actuator wire.

14. The apparatus as claimed in any preceding claim, where a first portion of the SMA actuator wire is couplable to a first crimp, and a second portion of the SMA actuator wire is couplable to a second crimp, the apparatus further comprising a slack addition module for adding slack to the SMA actuator wire before the crimping module closes the first and second crimps.

15. The apparatus as claimed in claim 14, the slack addition module comprising an adjustable lifting element for lifting the SMA actuator wire when the wire is provided between the first and second crimps.

16. The apparatus as claimed in claim 15, the slack addition module comprising a micrometer adjuster for raising and lowering the adjustable lifting element to provide a required amount of slack.

17. The apparatus as claimed in any preceding claim further comprising a cutting tool for cutting the SMA actuator wire after the SMA actuator wire is coupled to the at least one crimp.

18. The apparatus as claimed in any preceding claim, the crimping module comprising a punch and an anvil.

19. A method for assembling an actuating module comprising at least one shape memory alloy (SMA) actuator wire, the method comprising:

providing, in a holder, a component of the actuating module to which an SMA actuator wire is to be coupled, the component comprising at least a first crimp and a second crimp;

guiding, using an alignment module, a first portion of the SMA actuator wire into the first crimp;

guiding, using the alignment module, a second portion of the SMA actuator wire into the second crimp; and closing, using a crimping module, the first crimp to couple the first portion of the SMA actuator wire to the component, and the second crimp to couple the second portion of the SMA actuator wire to the component.

20. The method as claimed in claim 20 further comprising:

selectively removing some or all of an electrically insulating coating around the SMA actuator wire at the first portion and the second portion of the SMA actuator wire prior to the guiding steps.

5

21. The method as claimed in claim 19 or 20 further comprising:

adding slack to the SMA actuator wire before the crimping module closes the first and second crimps.

22. The method as claimed in any one of claims 19 to 21 further comprising:

io cutting the SMA actuator wire after the SMA actuator wire is coupled to the component.

23. A non-transitory data carrier carrying processor control code to implement the method of any one of claims 19 to 22.