CN111295512A

CN111295512A - Continuous routing of shape memory alloy actuators

Info

Publication number: CN111295512A
Application number: CN201880070923.0A
Authority: CN
Inventors: 杰弗里·法默; 詹姆斯·豪沃思; 尼古拉斯·亨利·雷达尔
Original assignee: Cambridge Mechatronics Ltd
Current assignee: Cambridge Mechatronics Ltd
Priority date: 2017-10-30
Filing date: 2018-10-30
Publication date: 2020-06-16
Also published as: WO2019086854A3; GB2581689A; GB201717858D0; GB2581689B; GB202006363D0; WO2019086854A2

Abstract

Embodiments of the present technology provide methods for manufacturing a large number of Shape Memory Alloy (SMA) actuator assemblies, which may also advantageously simplify and/or accelerate the process of manufacturing SMA actuator assemblies.

Description

Continuous routing of shape memory alloy actuators

The present application relates generally to techniques for fabricating Shape Memory Alloy (SMA) actuators, and more particularly to techniques for fabricating a large number of SMA actuators.

In a first method of the present technique, there is provided a method of manufacturing a Shape Memory Alloy (SMA) subassembly, comprising: providing a sheet of material comprising a plurality of stationary line attachment structures and a plurality of movable line attachment structures; laying at least one SMA actuator wire over a stationary wire attachment structure and a movable wire attachment structure using a continuous routing mechanism; attaching at least one SMA actuator wire to the stationary wire attachment structure and the movable wire attachment structure; and separating a plurality of SMA subassemblies from the sheet of material, each SMA subassembly comprising a sacrificial body portion integrally formed with at least one stationary wire attachment structure and at least one movable wire attachment structure.

In a second method of the present technology, there is provided a method for manufacturing a Shape Memory Alloy (SMA) actuation apparatus, comprising: providing a support structure; providing a movable component supported on a support structure in a manner that allows the movable component to move relative to the support structure; providing SMA subassemblies fabricated using any of the (continuous routing) methods described herein on the support structure and the movable component; attaching stationary and movable wire attachment structures of the SMA subassembly to the support structure and the movable component, respectively; and separating the stationary wire attachment structure and the movable wire attachment structure from the sacrificial body portion of the SMA subassembly.

In a third method of the present technique, there is provided an array of Shape Memory Alloy (SMA) subassemblies comprising: a plurality of sacrificial body portions connected in a one-dimensional or two-dimensional array, each sacrificial body portion integrally formed with at least one stationary wire attachment structure and at least one movable wire attachment structure; and at least one SMA actuator wire attached to the stationary wire attachment structure and the movable wire attachment structure, wherein the at least one SMA actuator wire is disposed on the stationary wire attachment structure and the movable wire attachment structure using a continuous routing process.

In a fourth method of the present technology, there is provided a method for manufacturing a Shape Memory Alloy (SMA) actuation apparatus, comprising: providing a plurality of support structures; providing a movable component on each of a plurality of support structures, each movable component being supported on a support structure in a manner that allows movement of the movable component relative to the support structure; providing an array of SMA subassemblies as described herein on a plurality of support structures and movable components; attaching the stationary wire attachment structure and the movable wire attachment structure of each SMA subassembly to the support structure and the movable member, respectively; cutting at least one SMA actuator wire between adjacent SMA subassemblies; and separating the stationary wire attachment structure and the movable wire attachment structure from the sacrificial body portion of each SMA subassembly.

In a fifth approach of the present technology, there is provided a Shape Memory Alloy (SMA) actuation apparatus manufactured using any of the continuous routing and assembly methods described herein.

In a sixth method of the present technique, there is provided a Shape Memory Alloy (SMA) actuation apparatus comprising: a stationary member comprising four stationary wire attachment structures; a movable member movable relative to the stationary member and including two movable wire attachment structures; and at least two Shape Memory Alloy (SMA) actuator wires connected between the movable and stationary parts and arranged to move the movable part upon contraction.

In a seventh method of the present technique, there is provided an apparatus comprising an SMA actuation apparatus of the type described herein.

The device may be any of: a smartphone, camera, foldable smartphone, foldable image capture device, foldable smartphone camera, foldable consumer electronics device, image capture device, 3D sensing device or system, consumer electronics device, mobile computing device, mobile electronic device, laptop, tablet computing device, e-reader (also known as e-book reader or e-book device), computing accessory or computing peripheral device (e.g., mouse, keyboard, headset, earphone, earbud, etc.), security system, medical device (e.g., endoscope), gaming system, gaming accessory (e.g., controller, headset, wearable controller, etc.), augmented reality system, augmented reality device, virtual reality system, virtual reality device, haptic device, medical device, wearable device, unmanned aerial vehicle (aerial, waterborne, wearable, etc.) Underwater, etc.), automotive vehicles, and vehicles (e.g., aircraft, spacecraft, submersible, automobile, etc.). It should be understood that this is a non-exhaustive list of example devices.

The SMA actuation apparatus described herein may be used in apparatuses/systems suitable for, for example, image capture, 3D sensing, depth mapping, aerial measurements, terrestrial measurements, measurements in or from space, hydrological measurements, underwater measurements, scene detection, collision warning, security, medical imaging, facial recognition, augmented and/or virtual reality, advanced driver assistance systems in vehicles, haptic, medical and surgical procedures, automated vehicles, gaming, gesture control/recognition, and robotic apparatuses.

Preferred features are set out in the appended dependent claims.

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

fig. 1A shows a schematic cross-sectional view of a camera arrangement;

FIG. 1B shows a top view of an arrangement of SMA actuator wires along an optical axis of the camera apparatus of FIG. 1A;

fig. 1C shows a perspective view of the arrangement of SMA actuator wires in the camera apparatus of fig. 1A;

FIG. 2A shows a schematic diagram of a continuous routing process of manufacturing an SMA subassembly of an SMA actuator;

FIG. 2B shows a top view of an SMA subassembly produced by the continuous routing process of FIG. 2A;

FIG. 3A shows a close-up of the movable wire attachment structure of the SMA subassembly;

fig. 3B shows a close-up of tabs (tabs) used to guide SMA actuator wires during the continuous routing process of fig. 2A;

FIG. 4 shows a schematic view of a wire dispensing head used in the continuous routing process of FIG. 2A; and

FIG. 5 shows a flowchart of example steps performed in a continuous routing process.

Broadly stated, embodiments of the present technology provide methods for manufacturing a large number of Shape Memory Alloy (SMA) actuator assemblies, which may also advantageously simplify and/or accelerate the process of manufacturing SMA actuator assemblies.

In international patent publications WO2013/175197 and WO2014/083318 a Shape Memory Alloy (SMA) actuator assembly is described for actuating movement of a movable element in two dimensions perpendicular to a primary axis. Such an actuator may be used for Optical Image Stabilization (OIS) in miniature cameras. These actuators comprise four SMA wires connected between a movable element and a fixed support. Each wire is connected at one of its ends to the movable element at a crimp (moving crimp) and at its other end to the support structure (stationary crimp). The actuator in WO2013/175197 is now described in more detail with reference to fig. 1A to 1C.

Fig. 1A shows a schematic cross-sectional view of a camera arrangement 1, which is an example of an SMA actuation arrangement and is taken along an optical axis O (which is an imaginary main axis). In order to clearly describe the main parts of the camera apparatus 1, the SMA actuator wires are not shown in fig. 1A, but are described later with reference to fig. 1B and 1C. The camera device 1 may be incorporated in a variety of devices such as a smartphone, a foldable image capture device, a foldable smartphone camera, a foldable consumer electronics device, an image capture device, a 3D sensing device or system, a consumer electronics device, a mobile computing device, a mobile electronic device, a laptop computer, a tablet computing device, an e-reader (also known as an e-book reader or e-book device), computing accessories or computing peripherals, security systems, medical devices (e.g., endoscopes), gaming systems, gaming accessories, augmented reality systems, augmented reality devices, virtual reality systems, virtual reality devices, wearable devices, unmanned aerial vehicles (airborne, waterborne, underwater, etc.), automotive vehicles, and vehicles (e.g., aircraft, spacecraft, submersible, automobile, etc.). It should be understood that this is a non-exhaustive list of example devices. In some cases, miniaturization is an important design criterion for the camera apparatus 1.

The camera arrangement 1 comprises a lens element 2, which lens element 2 is supported on a support structure 4 by a suspension system 7 in a manner allowing the lens element 2 to move relative to the support structure 4 in two orthogonal directions, each orthogonal direction being perpendicular to the optical axis O. The lens element 2 is thus a movable element/component.

The support structure 4 is a camera support supporting the image sensor 6 on the front side of its base 5. On the rear side of the base 5, an IC (integrated circuit) chip 30 in which the control circuit 40 is implemented and also a gyro sensor 47 are mounted.

The lens element 2 comprises a lens holder 21 in the form of a cylindrical body, which lens holder 21 supports lenses 22 arranged along the optical axis O, but in general any number of lenses 22 may be provided. The camera apparatus 1 is a miniature camera in which the diameter of the lens 22 (or individual lenses 22 if a plurality of lenses are provided) is less than or equal to 10mm, or more preferably less than or equal to 20 mm.

The lens element 2 is arranged to focus an image onto the image sensor 6. The image sensor 6 captures images and may be of any suitable type, such as a CCD (charge coupled device) or CMOS (complementary metal oxide semiconductor) device.

The lens 22 may be fixed relative to the lens holder 21 or alternatively may be supported on the lens holder in such a way that the lens 22 (or at least one lens 22 if multiple lenses are provided) can be moved along the optical axis O, for example in order to provide focusing. In the case where the lens 22 is movable along the optical axis O, a suitable actuation system (not shown) may be provided, for example using a voice coil motor or SMA actuator wires, for example as described in international patent publication No. WO 2007/113478.

In operation, the lens element 2 is moved relative to the image sensor 6 in two orthogonal directions (shown as X and Y) orthogonal to the optical axis O, as a result of which the image on the image sensor 6 is moved. This is used to provide Optical Image Stability (OIS) to compensate for image movement of the camera apparatus 1 caused by, for example, hand jitter.

In many known devices using SMA actuator wires to provide OIS functionality, for example as disclosed in international patent publications WO2010/029316 and WO2010/089529, OIS is provided by tilting the entire camera unit (substantially as a rigid body) including the lens element and the image sensor. This method of compensating for user hand trembling does in principle give the best OIS performance because it is difficult to align the lens element with the image sensor in a miniature camera and manufacturing tolerances are very tight. Furthermore, the compensated hand shake of the user is essentially the tilt of the camera, and it is therefore intuitive that the compensation should also tilt the camera. However, in this example, OIS is implemented in a different manner in order to alleviate several other problems.

The first problem is that the image sensor is moving relative to the fixed camera structure using the "camera tilt" method. This presents great difficulties for the wiring electrical connections from the image sensor to the fixed structure of the camera and to the main board of the mobile phone. This solution routes connections primarily around Flexible Printed Circuits (FPCs), but FPC design remains challenging due to the large number of connections and high data rates. Therefore, it is highly desirable that the image sensor remain stationary and stationary.

A second problem is that the camera tilt approach means that there is a camera structure comprising at least a lens and an image sensor, the support structure of which has to be tilted within the surrounding support structure. Because the camera has a limited packaging space (footprint), the tilt of the camera means that the camera thickness (height) of the OIS camera must be greater than an equivalent camera without OIS. In mobile phones, minimizing the height of the camera is an urgent need.

A third problem is that, since the entire camera is tilted, it is difficult to package the tilt actuator without increasing the packaging space of the camera compared to the packaging space of a camera without OIS.

Therefore, in fig. 1A, the lens element 2 is linearly moved in two orthogonal directions, both of which are perpendicular to the optical axis O, which may be referred to as "shift" or "OIS-shift". The resulting image compensation does not completely reverse the effect of the user's hand trembling, but the performance is considered to be sufficiently good in view of the above limitations and allows reducing the size of the camera device 1, in particular compared to devices using tilting.

Fig. 1B shows a top view of the arrangement of SMA actuator wires along the optical axis of the camera apparatus in fig. 1A. 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 rings at different angular positions around the optical axis O. 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 O and a second pair of

SMA actuator wires

12 and 14 arranged on opposite sides of the optical axis O. The first pair of

SMA actuator wires

11 and 13 is capable, upon selective actuation, of moving 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 is capable, upon selective actuation, of moving the lens element 2 relative to the support structure 4 in a second direction transverse to the first direction in said plane. Movement in directions other than parallel to the SMA actuator wires 11 to 14 may be driven by a combination of actuations of pairs of these SMA actuator wires 11 to 14 to provide a linear combination of movements in the transverse direction. Another way of observing this movement is that simultaneous contraction of any pair of the SMA actuator wires 11 to 14 adjacent to each other in the loop will drive the lens element 2 to move in a direction that bisects the two of the SMA actuator wires 11 to 14 (diagonally in fig. 1B, as indicated by arrows X and Y).

Thus, the SMA actuator wires 11 to 14 can be selectively driven to move the lens element 2 relative to the support structure 4 in two orthogonal directions perpendicular to the optical axis O to any position within a range of movement. The size 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.

Fig. 1C shows a perspective view of the arrangement of SMA actuator wires in the camera arrangement of fig. 1A. The actuator arrangement 10 comprises a total of four SMA actuator wires 11 to 14, the four SMA actuator wires 11 to 14 being connected between a support block 16 and a movable platform 15, the support block 16 forming part of the support structure 4 and being mounted to the base 5, the movable platform 15 forming part of the lens element 2 and being mounted to the rear of the lens plate 73 as shown in figure 1A.

Each of the SMA actuator wires 11 to 14 is held in tension so as to apply a force between the movable platform 15 and the support block 16 in a direction perpendicular to the optical axis O. 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 O.

The SMA actuator wires 11 to 14 are connected at one end to the movable platform 15 by respective crimp members 17 and at the other end to the support block 16 by crimp members 18. The crimping

members

17 and 18 crimp the wire to mechanically retain the wire, optionally reinforced by the use of an adhesive. The

crimp members

17 and 18 also provide electrical connections 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.

The present technique provides an improvement in the manufacture/assembly of actuators and camera modules of the type shown in fig. 1A-1C. The techniques described herein may be used to fabricate any type of SMA actuator, including the four-wire actuator described above and an eight-wire actuator of the type described in international patent publication No. WO 2011/104518. It should be understood that the techniques described herein may be used to fabricate SMA actuators or actuation devices for any device/system suitable for use in, for example, image capture, 3D sensing, depth mapping, aerial measurements, land measurements, measurements in or from space, hydrological measurements, underwater measurements, scene detection, collision warning, security, medical imaging, medical/surgical procedures, facial recognition, augmented and/or virtual reality, advanced driver assistance systems in vehicles, automated vehicles, gaming, gesture control/recognition, haptics, and robotic devices. Thus, the technique is not limited to fabricating SMA actuators for cameras, but may be used more broadly to fabricate SMA actuators for any technique.

Fig. 2A shows a schematic diagram of a continuous routing process 100 for manufacturing an SMA subassembly 102 for an SMA actuator. Fig. 2A shows one particular type of SMA subassembly 102, and it will be appreciated that the design of the subassembly may vary depending on the SMA actuator being manufactured. For example, an SMA actuator for delivering haptic feedback may comprise an SMA actuator wire held between/by two crimps (a moving crimp and a stationary crimp). In this case, the individual SMA subassemblies may be very simple. Thus, the SMA subassembly shown in fig. 2A-4 is merely one illustrative and non-limiting version of the subassembly, and those skilled in the art will appreciate that the specific features and layout of the subassembly may vary for a variety of reasons, including different technologies and different actuator designs.

The SMA actuator comprises a stationary part comprising four stationary wire attachment structures (e.g. crimps) and a movable part which is movable relative to the stationary part. The movable part also includes two movable wire attachment structures (e.g., crimps). The SMA actuator may comprise at least two Shape Memory Alloy (SMA) actuator wires connected between a movable part and a stationary part. The SMA actuator wires are arranged to move the movable member when contracted. The precise movement and control of the movable part may depend on the accuracy of the SMA actuator wires relative to each other and hence on the precise location of the wire attachment structure on the stationary and movable parts. Typically, the stationary and movable components of the SMA actuator and the wire attachment structure are assembled prior to attachment of the SMA actuator wire to the SMA actuator. However, this is a difficult process because SMA actuators are typically very small, for example 6.5mm by 6.5mm up to 12mm by 12 mm. Furthermore, the length of the SMA actuator wire attached to the wire attachment structure (e.g. held by the crimp) may need to be precisely controlled. If one SMA actuator wire is taut and the other SMA actuator wire is slack, it may be difficult to control the movement of the movable member.

Therefore, a problem that arises when manufacturing SMA actuator assemblies is how to increase the throughput (through put) of the routing process. One solution may include utilizing a continuous routing process, which may require some of the following: a single common crimp at each corner, a forming tab for wire routing and length control, SMA wire, wire dispensing head.

These problems can be solved by "off board" crimping, i.e. by attaching the SMA actuator wires to the wire attachment structure outside the SMA actuator and then assembling the SMA actuator. This simplifies the SMA actuator routing process. Furthermore, if the wire attachment structure is provided on a sheet or strip of material, a long length of SMA actuator wire may be attached to a large number of wire attachment structures. This can advantageously improve the manufacturing speed and productivity. The SMA subassemblies may be cut from the sheet/strip of material as needed and used to assemble the SMA actuator.

Fig. 2A shows a portion of a sheet/strip of material 108 used to perform "off-site" routing and crimping. The sheet/strip of material 108 may include a plurality of moveable line attachment structures 104a and a plurality of stationary line attachment structures 104 b. The movable wire attachment structure 104a and the stationary wire attachment structure 104b may be crimped portions. By shaping the material 108 into a desired shape, the movable wire attachment structures 104a and the stationary wire attachment structures 104b may be formed in the sheet of material 108. The sheet of material 108 may be formed of any material that is capable of making good electrical and mechanical connection of the

wire attachment structures

104a, 104b with the SMA actuator wires. For example, the sheet of material 108 may be formed of phosphor bronze or stainless steel.

The wire attachment structures (or crimps) 104a, 104b may be arranged on the sheet of material 108 such that the SMA subassembly 102 may be easily cut or separated from the sheet of material 108 after the routing process has been completed. Each SMA subassembly 102 may include four stationary wire attachment structures 104b and two movable wire attachment structures 104 a. Fig. 2A shows one complete SMA subassembly 102 and a portion of another subassembly. The two moveable wire attachment structures 104a may be held in a fixed position relative to each other by being part of the divider 107. Four stationary wire attachment structures 104b may be formed in the sheet of material 108 in fixed positions relative to each other and relative to the movable wire attachment structures 104 a.

The sheet of material 108 may also include one or more tabs or path control elements 106. The tabs/path control elements 106 may be used to control the position and length of SMA actuator wires disposed between the

wire attachment structures

104a, 104 b. A wire dispensing head 112 or similar device/tool may be used to dispense SMA actuator wire from a spool or reel (not shown). In an embodiment, the string dispensing head 112 may remain in a fixed position while the sheet of material 108 may move relative to the string dispensing head 112. Thus, as the sheet of material 108 moves past the wire dispensing head 112, the wire dispensing head 112 may dispense/lay the SMA actuator wires 110 onto the

wire attachment structures

104a, 104 b. Alternatively, the sheet of material 108 may remain in a fixed position while the string dispensing head 112 may move over the sheet of material 108. Optionally, both the wire dispensing head 112 and the sheet of material 108 are movable to enable the SMA actuator wires 110 to be laid onto the

wire attachment structures

104a, 104 b.

In an embodiment, the wire dispensing head 112 may be used to lay one SMA actuator wire 110 over half of the

wire attachment structures

104a, 104b, as shown in fig. 2A. Another wire dispensing head 112 or the same wire dispensing head 112 may be used to lay another SMA actuator wire 110 on the other half of the

wire attachment structures

104a, 104 b. Thus, the two SMA actuator wires 110 may be laid on the

wire attachment structures

104a, 104b in an intersecting or staggered manner. Optionally, the wire dispensing head 112 may be used to lay one SMA actuator wire 110 over all

wire attachment structures

104a, 104b of one SMA subassembly 102 before moving to the next subassembly. However, this may not be as effective as following a crossover.

As shown in fig. 2A, when the wire dispensing head 112 lays the SMA actuator wire 110, it may be disposed around the tab/path control element 106. The ears 106 may be disposed in the sheet of material 108 by shaping the sheet of material. The guide tabs 106 protrude from the sheet of material 108 and are disposed between adjacent

wire attachment structures

104a, 104b, and the wire direction guide tabs 114 are disposed between the wire attachment structures of adjacent subassemblies. In fig. 2A, three guide tabs 106 are provided between adjacent wire attachment structures, while four wire direction guide tabs 114 are provided between adjacent subassemblies 102. However, it should be understood that any number of guide tabs 106 may be provided to control the position and length of the SMA actuator wire 110 between the

wire attachment structures

104a, 104 b. Wire direction guiding tabs 114 disposed between adjacent subassemblies 102 may be used to control the angle of the SMA actuator wire 110 as the SMA actuator wire 110 leaves one subassembly and approaches the other so that the SMA actuator wire 110 does not over twist or bend. As shown in fig. 2A, the SMA actuator wires 110 may be interwoven between the guide tabs 106. A greater number of tabs 106 may increase the amount of SMA actuator wire 110 between each

wire attachment structure

104a, 104 b. This may be useful if the SMA actuator wires 110 are required to be relaxed (i.e., have zero tension) when the wires are not energized.

Fig. 2B shows a top view of the SMA subassembly 102 produced by the continuous routing process of fig. 2A. After the routing process is complete, the subassemblies 102 have been cut/separated from the sheet of material 108. When it is desired to assemble the SMA actuator, the subassembly 102 can be separated from the sheet of material 108. The

wire attachment structures

104a, 104b may be attached to the movable and stationary components of the SMA actuator by any suitable process, such as welding or laser welding. The moveable wire attachment structures 104a may be separated from the divider 107 after the welding process to the moveable component such that the moveable wire attachment structures 104a remain separated from each other by a desired distance during the welding process.

Accordingly, embodiments of the present technology may provide a Shape Memory Alloy (SMA) actuation apparatus comprising: a stationary component comprising four stationary wire attachment structures 104 b; a movable member movable relative to the stationary member and comprising two movable wire attachment structures 104 a; and at least two Shape Memory Alloy (SMA) actuator wires 110 connected between the movable and stationary parts and arranged to move the movable part when contracted.

The SMA actuation apparatus may comprise a total of two SMA actuator wires connected between the movable and stationary parts and arranged to move the movable part in contraction, wherein each SMA actuator wire: coupled at a first end to one of the four stationary wire attachment structures and at a second end to another of the four stationary wire attachment structures; and is coupled part-way along its length to one of the movable line attachment structures.

The SMA actuation apparatus may comprise a total of four SMA actuator wires connected between the movable and stationary parts and arranged to move the movable part in contraction, wherein each SMA actuator wire is: coupled at a first end to one of the four stationary wire attachment structures and at a second end to one of the movable wire attachment structures such that each movable wire attachment structure is coupled to two SMA actuator wires.

The movable part can be moved relative to the stationary part in two orthogonal directions perpendicular to an imaginary main axis extending through the movable part. Thus, in embodiments where the movable component is an optical component, the SMA actuation apparatus may be capable of providing Optical Image Stability (OIS).

In an embodiment, the SMA actuator wires of the SMA actuation apparatus may be relaxed.

The SMA actuation apparatus may be formed using a continuous routing process.

One problem that may arise when performing a continuous routing process is how to hold the SMA actuator wires in the movable crimp 104a so that a good electrical and mechanical connection is made when the crimps are closed. Therefore, it is necessary to hold the wire in the movable crimping portion 104a in preparation for crimping. One solution may be to use a single crimp (i.e., the movable crimp 104a) for OIS common corner connections. The wire is fed onto two shaped guides (formed up guides) on both sides of a single crimp to hold it in place. Fig. 3A shows a close-up of the movable wire attachment structure 104a of the SMA subassembly 102. Two crimp guide tabs 116 are provided on either side of the movable wire attachment structure 104a, and the SMA actuator wire 110 is passed around the crimp guide tabs 116 before and during the crimping process to hold the wire in the desired position in the crimp 104 a. A first crimp guide tab 116 may be disposed on a first side of each wire attachment structure and a second crimp guide tab 116 may be disposed on a second side of each wire attachment structure.

Another problem that may arise when using a continuous routing process is that the length of the SMA actuator wires between the respective

wire attachment structures

104a, 104b may be difficult to control. As mentioned above, it is desirable to ensure that the length of the SMA actuator wires in each subassembly 102 is precisely controlled. In an embodiment, the lengths of the SMA actuator wires between

adjacent crimps

104a, 104b may need to be identical or within a certain tolerance allowed. However, if the wire dispensing head 112 is used to lay the SMA actuator wires 110 on the sheet of material 108, the length may not be well controlled. Therefore, a problem of controlling the wire length and position in the continuous wiring process may occur. One solution may be to use shaped guide tabs 106 for line path and length control. Fig. 3B shows a close-up of the guide tabs 106 used to guide the SMA actuator wires during the continuous routing process of fig. 2A. The SMA actuator wire 110 passes or weaves between the tabs 106, and this technique is able to control both the position of the SMA actuator wire 110 relative to the crimps 104a, 104b and the amount of control wire 110 between adjacent crimps. The tabs 106 ensure that a fixed amount of SMA actuator wire 110 is provided along each length/side of the subassembly 102.

One problem that can arise is the problem of being able to wrap around a suitable dispensing head of small feature supply lines during continuous routing. One solution may be to use a thread dispensing head 110 in the form of a capillary or a small roller. Fig. 4 shows a schematic view of the wire dispensing head 110 used in the continuous routing process of fig. 2A, and how the wire dispensing head 110 needs to move around small features.

FIG. 5 shows a flowchart of example steps performed in a continuous routing process. The process begins by providing a sheet of material including a plurality of stationary line attachment structures and a plurality of movable line attachment structures (step S200). The process next lays at least one SMA actuator wire over the stationary and movable wire attachment structures using a continuous routing mechanism (step S202). Then, at least one SMA actuator wire is attached to the stationary wire attachment structure and the movable wire attachment structure (step S204). After the wire lay-up and attachment (crimping) steps are completed, one or more SMA subassemblies may be separated from the sheet of material when it is desired to assemble the SMA actuator (step S206). Each SMA subassembly includes a sacrificial body portion integrally formed with at least one stationary wire attachment structure and at least one movable wire attachment structure.

The step of laying at least one SMA actuator wire may comprise: laying one SMA actuator wire over the stationary wire attachment structure and the movable wire attachment structure such that each SMA subassembly comprises one SMA actuator wire that: coupled to the stationary wire attachment structure at a first end and coupled to the movable wire attachment structure at a second end.

The step of laying at least one SMA actuator wire may comprise: laying one SMA actuator wire over the stationary wire attachment structure and the movable wire attachment structure such that each SMA subassembly comprises one SMA actuator wire that: coupled at a first end to a first stationary wire attachment structure, coupled at a second end to a second stationary wire attachment structure, and coupled en route along its length to a movable wire attachment structure.

The step of laying at least one SMA actuator wire may comprise: laying two SMA actuator wires over the stationary wire attachment structure and the movable wire attachment structure such that each SMA subassembly comprises two SMA actuator wires, each SMA actuator wire: coupled at a first end to the stationary wire attachment structure and coupled at a second end to the movable wire attachment structure.

The step of laying at least one SMA actuator wire may comprise: laying a total of two SMA actuator wires on the stationary wire attachment structure and the movable wire attachment structure such that each SMA subassembly comprises two SMA actuator wires, each SMA actuator wire: a first stationary wire attachment structure coupled at a first end and a second stationary wire attachment structure coupled at a second end; and coupled en route to the movable wire attachment structure along its length.

The step of laying at least one SMA actuator wire may comprise: laying a total of four SMA actuator wires on the stationary wire attachment structure and the movable wire attachment structure such that each SMA subassembly comprises four SMA actuator wires, each SMA actuator wire: coupled at a first end to one of the four stationary wire attachment structures and at a second end to one of the two movable wire attachment structures such that each movable wire attachment structure is coupled to two SMA actuator wires.

The step of laying at least one SMA actuator wire may comprise: laying a total of four SMA actuator wires on the stationary wire attachment structure and the movable wire attachment structure such that each SMA subassembly comprises four SMA actuator wires, each SMA actuator wire: coupled at a first end to one of the four stationary wire attachment structures and coupled at a second end to one of the four movable wire attachment structures.

The step of providing a sheet of material may comprise providing a sheet of phosphor bronze, steel or stainless steel material.

The step of providing a sheet of material may comprise providing a sheet of etched material that has been shaped to provide a plurality of stationary wire attachment structures and a plurality of movable wire attachment structures.

In an embodiment, the plurality of stationary attachment structures and the plurality of movable wire attachment structures may be open crimps, and the step of laying the at least two SMA actuator wires over the stationary wire attachment structures and the movable wire attachment structures may comprise: at least one SMA actuator wire is laid over the stationary and movable open crimps. In this case, the step of attaching the at least one SMA actuator wire to the stationary wire attachment structure and the movable wire attachment structure may comprise: closing the stationary open crimp and the movable open crimp around the at least one SMA actuator wire; and applying a punch tool (punch tool) to each of the closed stationary crimp portion and the closed movable crimp portion.

The step of separating the plurality of SMA subassemblies may comprise applying a stamping tool to separate the body portion from the sheet of material. Alternatively, the step of separating the plurality of SMA subassemblies may comprise etching the sheet of material to separate the body portion from the sheet of material. Alternatively, the step of separating the plurality of SMA subassemblies may comprise cutting the sheet of material to separate the body portion from the sheet of material.

The step of separating the plurality of SMA subassemblies may comprise cutting at least one SMA actuator wire at a location on the sheet of material between adjacent SMA subassemblies. The cutting may be performed using a laser or a mechanical cutting process.

The step of laying the at least one SMA actuator wire may comprise interweaving the at least one SMA actuator wire around one or more guide tabs in the sheet of material.

The step of laying at least one SMA actuator wire may comprise: laying at least one SMA actuator wire on a first wire attachment structure; interweaving at least one SMA actuator wire between one or more guide tabs on the sheet of material to control the position and length of the SMA actuator wire between adjacent wire attachment structures; and laying at least one SMA actuator wire on the second wire attachment structure.

The step of laying at least one SMA actuator wire may comprise: at least one SMA actuator wire is laid over the wire attachment structure about one or more crimp guide tabs on the sheet of material in the vicinity of each wire attachment structure to retain the SMA actuator wire on the wire attachment structure. The first crimp guide tab may be disposed on a first side of the wire attachment structure and the second crimp guide tab may be disposed on a second side of the wire attachment structure.

The step of laying at least one SMA actuator wire may comprise interweaving the at least one SMA actuator wire around one or more wire direction guiding tabs on the sheet of material to control the angle of the SMA actuator wire between adjacent SMA subassemblies.

The present technology may provide a method for manufacturing a Shape Memory Alloy (SMA) actuation apparatus, comprising: providing a support structure; providing a movable component supported on the support structure in a manner that allows the movable component to move relative to the support structure; providing an SMA subassembly manufactured using the above method on a support structure and a movable component; attaching stationary and movable wire attachment structures of the SMA subassembly to the support structure and the movable component, respectively; and separating the stationary wire attachment structure and the movable wire attachment structure from the sacrificial body portion of the SMA subassembly.

The present techniques may provide an array of Shape Memory Alloy (SMA) subassemblies comprising: a plurality of sacrificial body portions connected in a one-dimensional or two-dimensional array, each sacrificial body portion integrally formed with at least one stationary wire attachment structure and at least one movable wire attachment structure; and at least one SMA actuator wire attached to the stationary wire attachment structure and the movable wire attachment structure, wherein the at least one SMA actuator wire is disposed on the stationary wire attachment structure and the movable wire attachment structure using a continuous routing process.

The array of SMA subassemblies may further include: a plurality of guide tabs for controlling the position and length of the SMA actuator wires between the wire attachment structures.

The array of SMA subassemblies may further include: at least one crimp guide tab near each wire attachment structure to retain the SMA actuator wire on the wire attachment structure during assembly. The first crimp guide tab may be disposed on a first side of each wire attachment structure and the second crimp guide tab may be disposed on a second side of each wire attachment structure.

The array of SMA subassemblies may further include: the plurality of wire directions guide the tabs to control the angle of the SMA actuator wires between adjacent sacrificial body portions.

Other embodiments of the present technology are set forth in the following numbered clauses:

1. an SMA four-wire actuator includes four stationary crimps and two moving crimps.

2. The SMA four-wire actuator according to clause 1, wherein each moving crimp is connected to two SMA wires.

3. An SMA actuator comprises two SMA wires, each wire being connected at its two ends to a stationary crimp and at its centre to a moving crimp.

4. An SMA actuator comprises two SMA wires, four stationary crimps and two moving crimps.

5. The SMA actuator according to

clause

3 or 4 is driven to provide two-dimensional movement.

6. An SMA actuator assembly process includes continuous routing.

7. The SMA actuator assembly process of clause 6, wherein the SMA actuator includes shaped tabs to control the path and length of the wire.

8. The SMA actuator assembly process of clause 6, wherein a wire dispensing head is used.

9. The SMA actuator assembly process of clause 8, wherein the dispensing head is capable of surrounding a small feature supply line.

10. The SMA actuator assembly process of clause 8, wherein the dispensing head comprises a capillary or roller.

11. An SMA actuator assembly process according to clauses 6-10 for producing a 4-wire actuator.

12. An SMA actuator assembly process according to clause 10 for producing an actuator according to clause 1 or 2.

13. An SMA actuator assembly process according to clauses 7-9 for producing an actuator according to clauses 3-5.

It should be appreciated by those of skill in the art that while the foregoing has described what is considered to be the best mode and other modes of carrying out the present technology where appropriate, the present technology should not be limited to the specific constructions and methods of the preferred embodiments disclosed in this specification. Those skilled in the art will recognize that the present technology has a wide range of applications, and that the embodiments can be modified in a wide range without departing from any inventive concept defined by the appended claims.

Claims

1. A method of manufacturing a Shape Memory Alloy (SMA) subassembly, comprising:

providing a sheet of material comprising a plurality of stationary wire attachment structures and a plurality of movable wire attachment structures;

laying at least one SMA actuator wire over the stationary wire attachment structure and the movable wire attachment structure using a continuous routing mechanism;

attaching the at least one SMA actuator wire to the stationary wire attachment structure and the movable wire attachment structure; and

separating a plurality of SMA subassemblies from the sheet of material, each SMA subassembly including a sacrificial body portion integrally formed with at least one stationary wire attachment structure and at least one movable wire attachment structure.

2. The method of claim 1, wherein the step of laying the at least one SMA actuator wire comprises:

laying one SMA actuator wire over the stationary wire attachment structure and the movable wire attachment structure such that each SMA subassembly comprises one SMA actuator wire that:

is coupled to the stationary wire attachment structure at the first end, an

Coupled to the movable wire attachment structure at the second end.

3. The method of claim 1, wherein the step of laying the at least one SMA actuator wire comprises:

coupled at a first end to a first stationary wire attachment structure,

is coupled to the second stationary wire attachment structure at the second end, an

Coupled en route to the moveable wire attachment structure along its length.

4. The method of claim 1, wherein the step of laying the at least one SMA actuator wire comprises:

laying two SMA actuator wires over the stationary wire attachment structure and the movable wire attachment structure such that each SMA subassembly comprises two SMA actuator wires, wherein each SMA actuator wire:

is coupled to the stationary wire attachment structure at the first end, an

Coupled to the movable wire attachment structure at the second end.

5. The method of claim 1, wherein the step of laying the at least one SMA actuator wire comprises:

laying a total of two SMA actuator wires over the stationary wire attachment structure and the movable wire attachment structure such that each SMA subassembly comprises two SMA actuator wires, wherein each SMA actuator wire:

coupled at a first end to a first stationary wire attachment structure,

a second stationary line attachment structure coupled at a second end; and is

Coupled en route to the moveable wire attachment structure along its length.

6. The method of claim 1, wherein the step of laying at least one SMA actuator wire comprises:

laying a total of four SMA actuator wires over the stationary wire attachment structure and the movable wire attachment structure such that each SMA subassembly comprises four SMA actuator wires, wherein each SMA actuator wire:

is coupled at a first end to one of four stationary wire attachment structures, an

Coupled to one of the two movable wire attachment structures at the second end such that each movable wire attachment structure is coupled to two SMA actuator wires.

7. The method of claim 1, wherein the step of laying at least one SMA actuator wire comprises:

Coupled at the second end to one of four movable wire attachment structures.

8. A method according to any preceding claim, wherein the step of providing a sheet of material comprises providing a sheet of phosphor bronze, steel or stainless steel material.

9. The method of any one of the preceding claims, wherein the step of providing a sheet of material comprises providing a sheet of etched material that has been shaped to provide the plurality of stationary line attachment structures and the plurality of movable line attachment structures.

10. A method according to any preceding claim, wherein the plurality of stationary wire attachment structures and the plurality of movable wire attachment structures are open crimps and the step of laying the at least one SMA actuator wire over the stationary wire attachment structures and the movable wire attachment structures comprises:

laying the at least one SMA actuator wire over the stationary open crimp and the movable open crimp.

11. The method of claim 10, wherein attaching the at least one SMA actuator wire to the stationary wire attachment structure and the movable wire attachment structure comprises:

closing the stationary open crimp and the movable open crimp around the at least one SMA actuator wire; and is

A press tool is applied to each of the closed stationary crimp and the closed movable crimp.

12. The method of any one of claims 1 to 11, wherein the step of separating the plurality of SMA subassemblies comprises: a stamping tool is applied to separate the body portion from the sheet of material.

13. The method of any one of claims 1 to 11, wherein the step of separating the plurality of SMA subassemblies comprises:

etching the sheet of material to separate the body portion from the sheet of material.

14. The method of any one of claims 1 to 11, wherein the step of separating the plurality of SMA subassemblies comprises:

cutting the sheet of material to separate the body portion from the sheet of material.

15. The method of any preceding claim, wherein the step of separating the plurality of SMA subassemblies comprises:

cutting the at least one SMA actuator wire at a location on the sheet of material between adjacent SMA subassemblies.

16. A method according to any one of claims 1 to 15, wherein the step of laying the at least one SMA actuator wire comprises interweaving the at least one SMA actuator wire through around one or more guide tabs in the sheet.

17. A method according to any one of claims 1 to 15, wherein the step of laying the at least one SMA actuator wire comprises:

laying the at least one SMA actuator wire on a first wire attachment structure;

interweaving the at least one SMA actuator wire between one or more guide tabs on the sheet of material to control the position and length of the SMA actuator wire between adjacent wire attachment structures; and

laying the at least one SMA actuator wire on a second wire attachment structure.

18. A method according to any preceding claim, wherein the step of laying the at least one SMA actuator wire comprises:

laying the at least one SMA actuator wire on a wire attachment structure about one or more crimp guide tabs on the sheet of material in the vicinity of each wire attachment structure to retain the SMA actuator wire on the wire attachment structure.

19. The method of claim 18, wherein a first crimp guide tab is disposed on a first side of the wire attachment structure and a second crimp guide tab is disposed on a second side of the wire attachment structure.

20. A method according to any preceding claim, wherein the step of laying the at least one SMA actuator wire comprises:

interweaving the at least one SMA actuator wire around one or more wire direction guiding tabs on the sheet of material to control an angle of the SMA actuator wire between adjacent SMA subassemblies.

21. A method for manufacturing a Shape Memory Alloy (SMA) actuation apparatus, comprising:

providing a support structure;

providing a movable component supported on the support structure in a manner that allows the movable component to move relative to the support structure;

providing an SMA subassembly manufactured using the method of any one of claims 1 to 20 on the support structure and the movable component;

attaching the stationary wire attachment structure and the movable wire attachment structure of the SMA subassembly to the support structure and the movable member, respectively; and

separating the stationary wire attachment structure and the movable wire attachment structure from the sacrificial body portion of the SMA subassembly.

22. An array of Shape Memory Alloy (SMA) subassemblies comprising:

a plurality of sacrificial body portions connected in a one-dimensional or two-dimensional array, each sacrificial body portion integrally formed with at least one stationary wire attachment structure and at least one movable wire attachment structure; and

at least one SMA actuator wire attached to the stationary wire attachment structure and the movable wire attachment structure, wherein the at least one SMA actuator wire is disposed on the stationary wire attachment structure and the movable wire attachment structure using a continuous routing process.

23. The SMA subassembly array of claim 22, further comprising:

a plurality of guide tabs for controlling the position and length of the SMA actuator wires between the wire attachment structures.

24. An array of SMA subassemblies according to claim 22 or 23, further comprising at least one crimp guide tab near each wire attachment structure to retain the SMA actuator wires on the wire attachment structure during assembly.

25. The SMA subassembly array of claim 24, wherein a first crimp guide tab is disposed on a first side of each wire attachment structure and a second crimp guide tab is disposed on a second side of each wire attachment structure.

26. An array of SMA subassemblies as claimed in any one of claims 22 to 25, further comprising a plurality of wire direction guiding tabs to control the angle of the SMA actuator wires between adjacent sacrificial body portions.

27. A method for manufacturing a Shape Memory Alloy (SMA) actuation apparatus, comprising:

providing a plurality of support structures;

providing a movable component on each of the plurality of support structures, each movable component being supported on the support structure in a manner that allows the movable component to move relative to the support structure;

providing an array of SMA subassemblies as claimed in any one of claims 22 to 27 on the plurality of support structures and the movable component;

attaching the stationary wire attachment structure and the movable wire attachment structure of each SMA subassembly to a support structure and a movable member, respectively;

cutting the at least one SMA actuator wire between adjacent SMA subassemblies; and

separating the stationary wire attachment structure and the movable wire attachment structure from the sacrificial body portion of each SMA subassembly.

28. A Shape Memory Alloy (SMA) actuation apparatus manufactured using the method of claim 21.

29. A Shape Memory Alloy (SMA) actuation apparatus comprising:

a stationary member comprising four stationary wire attachment structures;

a movable member movable relative to the stationary member and including two movable wire attachment structures; and

at least two Shape Memory Alloy (SMA) actuator wires connected between the movable and stationary components and arranged to move the movable component when contracted.

30. An SMA actuation apparatus according to claim 29, comprising a total of two SMA actuator wires connected between the movable and stationary parts and arranged to move the movable part on contraction, wherein each SMA actuator wire is:

coupled at a first end to one of the four stationary wire attachment structures,

coupled to another of the four stationary wire attachment structures at a second end; and is

Coupled en route along its length to one of the movable wire attachment structures.

31. An SMA actuation apparatus according to claim 30, comprising a total of four SMA actuator wires connected between the movable and stationary parts and arranged to move the movable part on contraction, wherein each SMA actuator wire is:

is coupled at a first end to one of the four stationary wire attachment structures, and

coupled to one of the movable wire attachment structures at the second end such that each movable wire attachment structure is coupled to two SMA actuator wires.

32. An SMA actuation apparatus according to claim 29, 30 or 31, wherein the movable member is movable relative to the stationary member in two orthogonal directions perpendicular to an imaginary main axis extending through the movable member.

33. An SMA actuation apparatus according to any one of claims 29 to 32, wherein the SMA actuator wires are relaxed.

34. An SMA actuation apparatus according to any one of claims 29 to 33, wherein the SMA actuation apparatus is formed using a continuous routing process.

35. An apparatus comprising an SMA actuation apparatus according to any one of claims 28 to 34.

36. The apparatus of claim 35, wherein the apparatus is any one of the following: a smartphone, a camera, a foldable smartphone, a foldable image capture device, a foldable smartphone camera, a foldable consumer electronic device, an image capture device, a 3D sensing device or system, a consumer electronic device, a mobile computing device, a mobile electronic device, a laptop, a tablet computing device, an e-reader, a computing accessory, a computing peripheral device, a security system, a medical device, a gaming system, a gaming accessory, an augmented reality system, an augmented reality device, a virtual reality system, a virtual reality device, a wearable device, a drone, an automated vehicle, and a vehicle.