Shape memory alloy actuator and method thereof

Abstract

An SMA actuator and associated methods are described. One embodiment of the actuator includes a base, a plurality of buckle arms, and at least a first shape memory alloy wire coupled to a pair of the buckle arms of the plurality of buckle arms. Another embodiment of the actuator includes a base and at least one bimorph actuator including a shape memory alloy material. The bimorph actuator is attached to the base.

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE Embodiments of the present invention relate to the field of shape memory alloy systems, and more particularly, to the field of shape memory alloy actuators and related methods. [Background technology]

[0002] Shape memory alloy (SMA) systems have a movable assembly or structure that can be used, for example, with a camera lens element as an autofocus drive. These systems can be surrounded by a structure such as a screening can. The movable assembly is supported for movement on a support assembly by bearings such as balls. A flexure element formed from a metal such as phosphor bronze or stainless steel has a movable plate and a flexure. The flexure extends between the movable plate and the stationary support assembly and acts as a spring to allow movement of the movable assembly relative to the stationary support assembly. The balls allow the movable assembly to move with little resistance. The movable assembly and the support assembly are connected by four shape memory alloy (SMA) wires that extend between the assemblies. Each of the SMA wires is attached at one end to the support assembly and at the opposite end to the movable assembly. The suspension is actuated by applying an electrical drive signal to the SMA wires. However, these types of systems suffer from the complexity of the system, resulting in a bulky system that requires a large footprint and a large clearance in height. Additionally, current systems fail to provide a high Z stroke range in a compact, low profile footprint. Summary of the Invention

[0003] An SMA actuator and associated methods are described. One embodiment of the actuator includes a base, a plurality of buckle arms, and at least a first shape memory alloy wire coupled to a pair of the buckle arms of the plurality of buckle arms. Another embodiment of the actuator includes a base and at least one bimorph actuator including a shape memory alloy material. The bimorph actuator is attached to the base.

[0004] Other features and advantages of embodiments of the present invention will become apparent from the accompanying drawings and from the detailed description that follows. Embodiments of the present invention are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings in which like reference symbols refer to similar elements and in which: [Brief description of the drawings]

[0005] [Figure 1a] 1 illustrates a lens assembly including an SMA actuator configured as a buckle actuator according to one embodiment. [Figure 1b] 1 illustrates an SMA actuator according to one embodiment. [Diagram 2] 1 illustrates an SMA actuator according to one embodiment. [Diagram 3] FIG. 1 illustrates an exploded view of an autofocus assembly including an SMA wire actuator according to one embodiment. [Figure 4] 1 illustrates an autofocus assembly including an SMA actuator according to one embodiment. [Diagram 5] 1 illustrates an SMA actuator including a sensor according to one embodiment. [Figure 6] 1A and 1B show top and side views of an SMA actuator configured as a buckle actuator according to one embodiment attached to a lens carriage. [Figure 7] 1 shows a side view of a portion of an SMA actuator according to the embodiment. [Figure 8] 1A-1C show multiple views of one embodiment of a buckle actuator. [Figure 9]1 illustrates a bimorph actuator having a lens carriage according to one embodiment. [Figure 10] FIG. 1 illustrates a cutaway view of an autofocus assembly including an SMA actuator according to one embodiment. [Figure 11a] 1A-1D show diagrams of bimorph actuators according to some embodiments. [Figure 11b] 1A-1D show diagrams of bimorph actuators according to some embodiments. [Figure 11c] 1A-1D show diagrams of bimorph actuators according to some embodiments. [Figure 12] 1 illustrates a diagram of an embodiment of a bimorph actuator, according to one embodiment. [Figure 13] 1 illustrates a cross section of an end pad of a bimorph actuator according to one embodiment. [Figure 14] 1 illustrates a cross section of a central feed pad of a bimorph actuator according to one embodiment. [Figure 15] 1 illustrates an exploded view of an SMA actuator including two buckle actuators according to one embodiment. [Figure 16] 1 illustrates an SMA actuator including two buckle actuators according to one embodiment. [Figure 17] FIG. 1 illustrates a side view of an SMA actuator including two buckle actuators according to one embodiment. [Figure 18] FIG. 1 illustrates a side view of an SMA actuator including two buckle actuators according to one embodiment. [Figure 19] 1 illustrates an exploded view of an assembly including an SMA actuator that includes two buckle actuators according to one embodiment. [Figure 20] 1 illustrates an SMA actuator including two buckle actuators according to one embodiment. [Figure 21] 1 illustrates an SMA actuator including two buckle actuators according to one embodiment. [Figure 22] 1 illustrates an SMA actuator including two buckle actuators according to one embodiment. [Diagram 23] 1 illustrates an SMA actuator including two buckle actuators and a coupler according to one embodiment. [Figure 24] FIG. 1 illustrates an exploded view of an SMA system including an SMA actuator including a buckle actuator with a laminate hammock according to one embodiment. [Diagram 25] 24 shows an SMA system including an SMA actuator including a buckle actuator 2402 with a laminate hammock according to one embodiment. [Figure 26] 1 illustrates a buckle actuator including a laminate hammock according to one embodiment. [Figure 27] 1 illustrates a laminate hammock for an SMA actuator according to one embodiment. [Figure 28] 1 illustrates a laminated crimp connection of an SMA actuator according to one embodiment. [Figure 29] 1 shows an SMA actuator including a buckle actuator with a laminate hammock. [Diagram 30] FIG. 1 illustrates an exploded view of an SMA system including an SMA actuator, including a buckle actuator, according to one embodiment. [Diagram 31] 1 illustrates an SMA system including an SMA actuator, including a buckle actuator, according to one embodiment. [Diagram 32] 1 illustrates an SMA actuator including a buckle actuator according to one embodiment. [Diagram 33] 1 illustrates a two-yoke capture joint for a pair of buckle arms of an SMA actuator according to one embodiment. [Diagram 34] 13 illustrates a resistance weld crimp of an SMA actuator used to attach the SMA wire to a buckle actuator according to one embodiment. [Diagram 35] 1 shows an SMA actuator including a buckle actuator with a two yoke capture joint. [Diagram 36] 1 illustrates an SMA bimorph liquid lens according to one embodiment. [Figure 37] 1 illustrates a perspective view of an SMA bimorph liquid lens according to one embodiment. [Figure 38] 1A-1D show cross-sectional and bottom views of an SMA bimorph liquid lens according to one embodiment. [Figure 39] 1 illustrates an SMA system including an SMA actuator with a bimorph actuator, according to one embodiment. [Diagram 40] 1 illustrates an SMA actuator having a bimorph actuator according to one embodiment. [Diagram 41] 13 shows the length of the bimorph actuator and the location of the bond pads for the SMA wires to extend the wire length beyond the bimorph actuator. [Diagram 42] FIG. 1 illustrates an exploded view of an SMA system including a bimorph actuator according to one embodiment. [Diagram 43] 1 illustrates an exploded view of a small portion of an SMA actuator according to one embodiment. [Diagram 44] 1 illustrates a small portion of an SMA actuator according to one embodiment. [Diagram 45] 1 illustrates a five-axis sensor shifting system according to one embodiment. [Diagram 46] 1 illustrates an exploded view of a five-axis sensor shifting system according to one embodiment. [Figure 47] 1 shows an SMA actuator including a bimorph actuator integrated into the circuit for all actuation, according to one embodiment. [Figure 48] 1 shows an SMA actuator including a bimorph actuator integrated into the circuit for all actuation, according to one embodiment. [Figure 49] 1 illustrates a cross section of a five-axis sensor shifting system according to one embodiment. [Figure 50] 1 illustrates an SMA actuator according to an embodiment, including a bimorph actuator. [Figure 51] 13A-13C show top views of an SMA actuator according to one embodiment, including a bimorph actuator that moved an image sensor to different x and y positions. [Figure 52] 1 illustrates an SMA actuator including a bimorph actuator configured as a box bimorph autofocus according to one embodiment. [Diagram 53] 1 illustrates an SMA actuator including a bimorph actuator according to one embodiment. [Figure 54] 1 illustrates an SMA actuator including a bimorph actuator according to one embodiment. [Figure 55] 1 illustrates an SMA actuator including a bimorph actuator according to one embodiment. [Figure 56] 1 illustrates an SMA system including an SMA actuator according to one embodiment, including a bimorph actuator. [Figure 57] FIG. 1 shows an exploded view of an SMA system including an SMA actuator according to one embodiment, including a bimorph actuator configured as a two-axis lens-shifting OIS. [Figure 58] 1 illustrates a cross section of an SMA system including an SMA actuator according to one embodiment, including a bimorph actuator configured as a two-axis lens shift OIS. [Figure 59] 1 illustrates a box bimorph actuator according to one embodiment. [Figure 60] 1 illustrates an SMA system including an SMA actuator according to one embodiment, including a bimorph actuator. [Figure 61] 1 illustrates an exploded view of an SMA system including an SMA actuator according to one embodiment, including a bimorph actuator. [Figure 62] 1 illustrates a cross section of an SMA system including an SMA actuator according to one embodiment, including a bimorph actuator. [Figure 63] 1 illustrates a box bimorph actuator according to one embodiment. [Figure 64] 1 illustrates an SMA system including an SMA actuator according to one embodiment, including a bimorph actuator. [Figure 65]1 illustrates an exploded view of an SMA system including an SMA actuator according to one embodiment, including a bimorph actuator. [Figure 66] 1 illustrates an SMA system including an SMA actuator according to one embodiment, including a bimorph actuator. [Figure 67] 1 illustrates an SMA system including an SMA actuator according to one embodiment, including a bimorph actuator. [Figure 68] 1 illustrates an SMA system including an SMA actuator according to one embodiment, including a bimorph actuator. [Figure 69] 1 illustrates an exploded view of an SMA including SMA actuator according to one embodiment, including a bimorph actuator. [Figure 70] 1 illustrates a cross section of an SMA system including an SMA actuator according to one embodiment, including a bimorph actuator configured as a three-axis sensor-shifting OIS. [Figure 71] 1 illustrates a box bimorph actuator component according to one embodiment. [Figure 72] 1 illustrates a flexible sensor circuit for use in an SMA system according to one embodiment. [Figure 73] 1 illustrates an SMA system including an SMA actuator according to one embodiment, including a bimorph actuator. [Figure 74] 1 illustrates an exploded view of an SMA system including an SMA actuator according to one embodiment, including a bimorph actuator. [Figure 75] 1 illustrates a cross section of an SMA system including an SMA actuator according to one embodiment. [Figure 76] 1 illustrates a box bimorph actuator according to one embodiment. [Figure 77] 1 illustrates a flexible sensor circuit for use in an SMA system according to one embodiment. [Figure 78] 1 illustrates an SMA system including an SMA actuator according to one embodiment, including a bimorph actuator. [Figure 79]1 illustrates an exploded view of an SMA system including an SMA actuator according to one embodiment, including a bimorph actuator. [Figure 80] 1 illustrates a cross section of an SMA system including an SMA actuator according to one embodiment. [Figure 81] 1 illustrates a box bimorph actuator according to one embodiment. [Figure 82] 1 illustrates a flexible sensor circuit for use in an SMA system according to one embodiment. [Figure 83] 1 illustrates an SMA system including an SMA actuator according to one embodiment, including a bimorph actuator. [Figure 84] FIG. 1 illustrates an exploded view of an SMA system including an SMA actuator according to one embodiment. [Figure 85] 1 illustrates a cross section of an SMA system including an SMA actuator according to one embodiment, including a bimorph actuator. [Figure 86] 1 illustrates a box bimorph actuator for use in an SMA system according to one embodiment. [Figure 87] 1 illustrates a flexible sensor circuit for use in an SMA system according to one embodiment. [Figure 88] 1 illustrates exemplary dimensions of a bimorph actuator of an SMA actuator according to several embodiments. [Figure 89] 1 illustrates a lens system for a folded camera according to one embodiment. [Figure 90] 1 illustrates several embodiments of a lens system including a liquid lens according to one embodiment. [Figure 91] 1 illustrates a folding lens, which is a prism, disposed on an actuator, according to one embodiment. [Figure 92] 1 illustrates a bimorph arm with an offset according to one embodiment. [Figure 93] 1 illustrates a bimorph arm with an offset and a limiter according to one embodiment. [Figure 94]1 illustrates a bimorph arm with an offset and a limiter according to one embodiment. [Figure 95] 1 illustrates an embodiment of a base including a bimorph arm with an offset according to one embodiment. [Figure 96] 1 illustrates an embodiment of a base including two bimorph arms with an offset according to one embodiment. [Figure 97] 1 illustrates a buckler arm including a load point extension according to one embodiment. [Figure 98] A buckler arm 9801 is shown including a load point extension 9810 according to one embodiment. [Figure 99] 1 illustrates a bimorph arm including a load point extension according to one embodiment. [Figure 100] 1 illustrates a bimorph arm including a load point extension according to one embodiment. [Figure 101] 1 illustrates an SMA optical image stabilization mechanism according to one embodiment. [Figure 102] 4 shows an SMA material attachment 40 for the moving part according to one embodiment. [Figure 103] 1 illustrates an SMA mount for a stationary plate with resistance welded SMA wire attached, according to one embodiment. [Figure 104] 1 shows an SMA actuator 45 that includes a buckle actuator according to one embodiment. [Figure 105a] 1 illustrates a resistance weld crimp including islands for an SMA actuator according to one embodiment. [Figure 105b] 1 illustrates a resistance weld crimp including islands for an SMA actuator according to one embodiment. [Fig. 106] 13 illustrates the relationship between bending surface z offset, trough width, and peak force of a bimorph beam according to one embodiment. [Figure 107] 13 shows an example of how box volume, an approximation of a box that encompasses the entire bimorph actuator, relates to work per bimorph component according to one embodiment. [Figure 108]1 illustrates a liquid lens actuated using a buckle actuator according to one embodiment. [Fig. 109] 13 illustrates an unanchored load point end of a bimorph arm according to one embodiment. [Figure 110] 13 illustrates an unanchored load point end of a bimorph arm according to one embodiment. [Figure 111] 13 illustrates an unanchored load point end of a bimorph arm according to one embodiment. [Figure 112] 13 illustrates an unanchored load point end of a bimorph arm according to one embodiment. [Figure 113] 1 illustrates a fixed end of a bimorph arm according to one embodiment. [Fig. 114] 1 illustrates a fixed end of a bimorph arm according to one embodiment. [Fig. 115] 1 illustrates a fixed end of a bimorph arm according to one embodiment. [Fig. 116] 1 illustrates a fixed end of a bimorph arm according to one embodiment. [Fig. 117] FIG. 13 illustrates a rear view of a fixed end of a bimorph arm according to one embodiment. [Fig. 118] 13 illustrates an unanchored load point end of a bimorph arm according to one embodiment. [Figure 119] 13 shows a free load point end of a bimorph arm according to an alternative embodiment. [Figure 120] 13 shows a free load point end of a bimorph arm according to an alternative embodiment. [Figure 121] 13 shows a free load point end of a bimorph arm according to an alternative embodiment. [Figure 122] 13 shows a free load point end of a bimorph arm according to an alternative embodiment. [Figure 123] 1 illustrates a fixed end of a bimorph arm according to one embodiment. [Figure 124] 1 illustrates a fixed end of a bimorph arm according to one embodiment. [Fig. 125] 1 illustrates a fixed end of a bimorph arm according to one embodiment. [Fig. 126] 1 illustrates a balanced bimorph actuator according to one embodiment. [Figure 127] 1 illustrates optical image stabilization including a balanced bimorph actuator, according to one embodiment. [Figure 128] 1 illustrates a balanced bimorph actuator according to one embodiment. [Figure 129] 1 illustrates a balanced bimorph actuator according to one embodiment that includes a polyimide layer configured to retain and isolate metal components. [Fig. 130] 1 illustrates a balanced bimorph actuator according to one embodiment that includes a common base island. [Fig. 131] 1 illustrates a balanced bimorph actuator according to one embodiment. [Fig. 132] 1 illustrates a balanced bimorph actuator according to one embodiment that includes a polyimide layer configured to retain and isolate metal components. [Fig. 133] 1 illustrates a balanced bimorph actuator according to one embodiment, including a control input pad and a ground pad. [Fig. 134] 1 illustrates a balanced bimorph actuator according to one embodiment. [Fig. 135] 1 illustrates a balanced bimorph actuator according to one embodiment that includes a single SMA wire. [Fig. 136] 1 illustrates a balanced bimorph actuator according to one embodiment, including one configured for a single SMA wire, a control input pad, and a ground pad. [Fig. 137] 1 illustrates a balanced bimorph actuator according to one embodiment. [Figure 138] 13 illustrates a balanced bimorph actuator with alternating orientations according to an embodiment that includes a polyimide layer configured to retain and isolate metal components. [Figure 139] 1 illustrates a balanced bimorph actuator according to one embodiment, including a control input pad and a ground pad. [Fig. 140]1 illustrates optical image stabilization including a balanced bimorph actuator, according to one embodiment. [Fig. 141] FIG. 2 illustrates an exploded view of optical image stabilization including a balanced bimorph actuator, according to one embodiment. [Fig. 142] 1 illustrates optical image stabilization including a balanced bimorph actuator, according to one embodiment. [Fig. 143] 1 illustrates a sensor-shifting optical image stabilization including a bimorph actuator according to one embodiment. [Fig. 144] 1 illustrates optical image stabilization including a balanced bimorph actuator, according to one embodiment. [Fig. 145] 1 shows a metal outer housing manufactured as a molded metal that is attached with molded plastic in an insert molding process, according to one embodiment. [Fig. 146] 1 illustrates a metal outer can embodiment that includes a pocket formed into the side of the outer can that is configured to allow for flush mounting of a bimorph actuator as described herein. [Fig. 147] 1 illustrates optical image stabilization including a bimorph actuator, according to one embodiment. [Fig. 148A] FIG. 1 is an isometric view of a bimorph actuator with shaped friction-reducing spheres. [Fig. 148B] FIG. 13 is a detailed view of the free load point end and the friction reducing sphere formed thereon. [Figure 149] 148B is a top view and a side view of the formed depression of FIG. 148A according to one embodiment. [Fig. 150] 1A-1D are top and side views of a bimorph actuator having a ball bearing housed in the free load point end, according to one embodiment. [Fig. 151] 1A-1D are top and side views of a bimorph actuator having a ball bearing housed in the free load point end, according to one embodiment. [Fig. 152]1A-1D are top and side views of a bimorph actuator having a spherical bearing housed within the free load point end, according to one embodiment. [Fig. 153] 1A-1D are top and side views of a bimorph actuator having a spherical bearing housed within the free load point end, according to one embodiment. [Fig. 154A] 1A-1D are top and side views of a spherical bearing at an open, unfixed load point end according to one embodiment. [Fig. 154B] 1A-1D are top and side views of a spherical bearing at the closed, unlocked load point end according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0006] Described herein are embodiments of SMA actuators that include a compact footprint while providing a high actuation height, e.g., movement in the positive z-axis direction (z-direction), referred to herein as the z-stroke. SMA actuator embodiments include SMA buckle actuators and SMA bimorph actuators. SMA actuators can be used to mechanically collide two surfaces to provide a vibration sensation typically found in haptic feedback sensors and devices, and other systems in which actuators are used, in many applications including, but not limited to, lens assemblies as autofocus actuators, microfluidic pumps, sensor shifting, optical image stabilization, optical zoom assemblies, and other systems in which actuators are used. For example, actuator embodiments described herein can be used as haptic feedback actuators for use in mobile phones or wearable devices configured to provide a user with an alarm, notification, alert, response of a touched area or a pressed button. Additionally, more than one SMA actuator can be used in a system to achieve a larger stroke.

[0007] In various embodiments, the SMA actuator has a z-stroke greater than 0.4 millimeters. Additionally, the SMA actuator of various embodiments has a z-height of 2.2 millimeters or less when the SMA actuator is in its initial, de-actuated position. Various embodiments of an SMA actuator configured as an autofocus actuator in a lens assembly may have a footprint as small as 3 millimeters greater than the lens inner diameter ("ID"). According to various embodiments, the SMA actuator may have a wider footprint in one direction to accommodate components including, but not limited to, sensors, wires, traces, and connectors. According to some embodiments, the footprint of the SMA actuator is 0.5 millimeters greater in one direction, e.g., the length of the SMA actuator is 0.5 millimeters greater than its width.

[0008] FIG. 1a illustrates a lens assembly including an SMA actuator configured as a buckle actuator according to one embodiment. FIG. 1b illustrates an SMA actuator configured as a buckle actuator according to one embodiment. Buckle actuator 102 is coupled to base 101. As shown in FIG. 1b, SMA wire 100 is attached to buckle actuator 102 such that when SMA wire 100 is actuated and contracts, buckle actuator 102 buckles, resulting in at least a central portion 104 of each buckle actuator 102 moving in a z-stroke direction, e.g., in the positive z-direction, as indicated by arrow 108. According to some embodiments, SMA wire 100 is actuated when an electric current is supplied to one end of the wire through a wire retainer, such as crimp structure 106. The electric current flows through SMA wire 100 and heats it due to the inherent resistance of the SMA material from which SMA wire 100 is made. The other side of the SMA wire 100 has a wire retainer such as a crimp structure 106 that connects the SMA wire 100 and completes the circuit to ground. Heating the SMA wire 100 to a sufficient temperature changes the specific material properties from a martensite crystal structure to an austenite crystal structure, which causes the length of the wire to change. Changing the current changes the temperature of the wire, and therefore the length of the wire, which is used to activate and deactivate the actuator to control the movement of the actuator in at least the Z direction. Those skilled in the art will appreciate that other techniques can be used to supply current to the SMA wire.

[0009] Figure 2 illustrates an SMA actuator configured as an SMA bimorph actuator according to one embodiment. As shown in Figure 2, the SMA actuator includes a bimorph actuator 202 coupled to a base 204. The bimorph actuator 202 includes an SMA ribbon 206. The bimorph actuator 202 is configured to move at least an unanchored end of the bimorph actuator 202 in a z-stroke direction 208 as the SMA ribbon 206 contracts.

[0010] FIG. 3 illustrates an exploded view of an autofocus assembly including an SMA actuator according to one embodiment. As shown, the SMA actuator 302 is configured as a buckle actuator according to embodiments described herein. The autofocus assembly also includes an optical image stabilization ("OIS") 304, a lens carriage 306 configured to hold one or more optical lenses using techniques such as those known in the art, a return spring 308, a vertical plain bearing 310, and a guide cover 312. The lens carriage 306 is configured to slide against the vertical plain bearing 310 as the SMA actuator 302 moves in a z-stroke direction, e.g., a positive z-direction, when the SMA wire is actuated, pulling and buckling the buckle actuator 302 using techniques such as those described herein. The return spring 308 is configured to apply a force in a direction opposite to the z-stroke direction on the lens carriage 306 using techniques such as those known in the art. The return spring 308 is configured to move the lens carriage 306 in the opposite direction of the z-stroke when the tension in the SMA wire decreases as the SMA wire is deactuated, according to various embodiments. When the tension in the SMA wire decreases to an initial value, the lens carriage 306 moves to its lowest height in the z-stroke direction. Figure 4 shows an autofocus assembly including an SMA wire actuator according to the embodiment shown in Figure 3.

[0011] FIG. 5 illustrates an SMA wire actuator according to one embodiment that includes a sensor. In various embodiments, the sensor 502 is configured to measure the z-direction movement of the SMA actuator, or the movement of a component that the SMA actuator is moving, using techniques such as those known in the art. The SMA actuator includes one or more buckle actuators 506 configured to actuate using one or more SMA wires 508 similar to those described herein. For example, in the autofocus assembly described with reference to FIG. 4, the sensor is configured to determine the amount that the lens carriage 306 moves in the z-direction 504 from an initial position, using techniques such as those known in the art. According to some embodiments, the sensor is a tunnel magneto resistance (TMR) sensor.

[0012] FIG. 6 shows a top view and a side view of an SMA actuator 602 configured as a buckle actuator according to one embodiment with a lens carriage 604 attached. FIG. 7 shows a side view of a portion of the SMA actuator 602 according to the embodiment shown in FIG. 6. According to the embodiment shown in FIG. 7, the SMA actuator 602 includes a slide base 702. According to one embodiment, the slide base 702 is formed of a metal, such as stainless steel, using techniques such as those known in the art. However, one of ordinary skill in the art will understand that other materials may be used to form the slide base 702. Additionally, the slide base 702 has a spring arm 612 coupled to the SMA actuator 602 according to some embodiments. According to various embodiments, the spring arm 612 is configured to serve two functions. The first function is to help push an object, such as the lens carriage 604, into the vertical slide surface of the guide cover. In this example, the spring arm 612 preloads the lens carriage 604 against this surface to ensure that the lens does not tilt during actuation. In some embodiments, the vertical slide surface 708 is configured to mate with a guide cover. A second function of the spring arm 612 is to help pull the SMA actuator 602 back, for example in the negative z direction, after the SMA wire 608 has moved the SMA actuator 602 in the z-stroke direction, i.e., the positive z direction. Thus, when the SMA wire 608 is actuated, the SMA wire contracts to move the SMA actuator 602 in the z-stroke direction, and the spring arm 612 is configured to move the SMA actuator 602 in the opposite z-stroke direction when the SMA wire 608 is deactuated.

[0013] The SMA actuator 602 also includes a buckle actuator 710. In various embodiments, the buckle actuator 710 is formed of a metal, such as stainless steel. Additionally, the buckle actuator 710 includes a buckle arm 610 and one or more wire retainers 606. According to the embodiment shown in FIGS. 6 and 7, the buckle actuator 710 includes four wire retainers 606. Each of the four wire retainers 606 is configured to receive an end of an SMA wire 608 and hold the end of the SMA wire 608 such that the SMA wire 608 is attached to the buckle actuator 710. In various embodiments, the four wire retainers 606 are crimps configured to clamp a portion of the SMA wire 608 to attach the wire to the crimp. One skilled in the art will appreciate that the SMA wire 608 may be attached to the wire retainers 606 using techniques known in the art, including, but not limited to, adhesives, solder, and mechanical attachment. A smart memory alloy (SMA) wire 608 extends between the pair of wire retainers 606 and is configured to move a buckle arm 610 of a buckle actuator 710 when the SMA wire 608 is actuated, thereby drawing the pair of wire retainers 606 closer together. According to various embodiments, the SMA wire 608 is electrically actuated to move and control the position of the buckle arm 610 when an electric current is applied to the SMA wire 608. The SMA wire 608 is deactuated when the electric current is removed or falls below a threshold. This causes the pair of wire retainers 606 to move apart and the buckle arm 610 to move in a direction opposite to the direction in which the SMA wire 608 is actuated. According to various embodiments, the buckle arm 610 is configured to have an initial angle of 5 degrees with respect to the slide base 702 when the SMA wire is deactuated in its initial position. And, according to various embodiments, at full stroke, or when the SMA wire is fully actuated, the buckle arm 610 is configured to have an angle of 10 to 12 degrees with respect to the slide base 702.

[0014] According to the embodiment shown in Figures 6 and 7, the SMA actuator 602 also includes a sliding bearing 706 configured between the sliding base 702 and the wire retainer 606. The sliding bearing 706 is configured to minimize any friction between the sliding base 702 and the buckle arms 610 and / or the wire retainer 606. The sliding bearing for some embodiments is attached to the sliding bearing 706. According to various embodiments, the sliding bearing is formed of polyoxymethylene (POM). One skilled in the art will appreciate that other structures can be used to reduce any friction between the buckle actuator and the base.

[0015] According to various embodiments, the slide base 702 is configured to mate with an assembly base 704, such as an autofocus base for an autofocus assembly. The actuator base 704, according to some embodiments, includes an etched shim. Such an etched shim may be used to provide clearance for wires and crimps when the SMA actuator 602 is part of an assembly, such as an autofocus assembly.

[0016] FIG. 8 shows multiple views of an embodiment of a buckle actuator 802 with respect to the x-axis, y-axis, and z-axis. In the orientation of FIG. 8, the buckle arms 804 are configured to move in the z-axis when the SMA wires are actuated and deactuated as described herein. According to the embodiment shown in FIG. 8, the buckle arms 804 are coupled to each other via a central portion, such as a hammock portion 806. The hammock portion 806, according to various embodiments, is configured to support a portion of an object acted upon by the buckle actuator, for example, a lens carriage that is moved by the buckle actuator using techniques such as those described herein. According to some embodiments, the hammock portion 806 is configured to provide lateral stiffness to the buckle actuator during actuation. In other embodiments, the buckle actuator does not include the hammock portion 806. According to these embodiments, the buckle arms are configured to act upon an object to move the object. For example, the buckle arms are configured to act directly upon a feature of the lens carriage to push the lens carriage upward.

[0017] FIG. 9 illustrates an SMA actuator configured as an SMA bimorph actuator according to one embodiment. The SMA bimorph actuator includes bimorph actuators 902, including those described herein. According to the embodiment shown in FIG. 9, one end 906 of each of the bimorph actuators 902 is attached to a base 908. According to some embodiments, the one end 906 is welded to the base 908. However, one of ordinary skill in the art will appreciate that other techniques may be used to attach the one end 906 to the base 908. FIG. 9 also illustrates a lens carriage 904 arranged such that the bimorph actuators 902 are configured to collapse in the z-direction upon actuation, lifting the carriage 904 in the z-direction. In some embodiments, a return spring is used to push the bimorph actuators 902 back to their initial position. The return spring may be configured as described herein to help push the bimorph actuators down to their initial unactuated position. Due to the small footprint of the bimorph actuators, SMA actuators can be made with a smaller footprint than current actuator technology.

[0018] 10 shows a cutaway view of an autofocus assembly including an SMA actuator according to one embodiment, including a position sensor such as a TMR sensor. The autofocus assembly 1002 includes a position sensor 1004 attached to a movable spring 1006 and a magnet 1008 attached to a lens carriage 1010 of the autofocus assembly, including an SMA actuator as described herein. The position sensor 1004 is configured to determine the amount of movement that the lens carriage 1010 moves in the z-direction 1005 from an initial position based on the distance of the magnet 1008 from the position sensor 1004, using techniques such as those known in the art. According to some embodiments, the position sensor 1004 is electrically coupled to a controller or processor, such as a central processing unit, using a number of electrical traces on the spring arm of the movable spring 1006 of the optical image stabilization assembly.

[0019] 11a-11c show diagrams of a bimorph actuator according to some embodiments. According to various embodiments, the bimorph actuator 1102 includes a beam 1104 and one or more SMA materials 1106, such as SMA ribbons 1106b (e.g., as shown in the perspective view of a bimorph actuator including an SMA ribbon according to an embodiment of FIG. 11b) or SMA wires 1106a (e.g., as shown in the cross section of a bimorph actuator including an SMA wire according to an embodiment of FIG. 11a). The SMA material 1106 is attached to the beam 1104 using techniques such as those described herein. According to some embodiments, the SMA material 1106 is attached to the beam 1104 using an adhesive film material 1108. In various embodiments, ends of the SMA material 1106 are electrically and mechanically coupled to contacts 1110 configured to provide electrical current to the SMA material 1106 using techniques such as those known in the art. According to various embodiments, the contacts 1110 (e.g., as shown in Figures 11a and 11b) are gold-plated copper pads. According to several embodiments, a bimorph actuator 1102 having a length of about 1 millimeter is configured to generate a large stroke and a pushing force of 50 milliNewtons (mN), for example, as illustrated in Figure 11c, and is used as part of a lens assembly. According to some embodiments, the use of a bimorph actuator 1102 having a length greater than 1 millimeter generates a larger stroke but a smaller force than one having a length of 1 millimeter. In one embodiment, the bimorph actuator 1102 includes a 20 micrometer thick SMA material 1106, a 20 micrometer thick insulator 1112, such as a polyimide insulator, and a 30 micrometer thick stainless steel beam 1104 or base metal. Various embodiments include a second insulator 1114 disposed between the contact layer including the contacts 1110 and the SMA material 1106. The second insulator 1114 is configured to insulate the SMA material 1106 from portions of the contact layer that are not used as contacts 1110, according to some embodiments.In some embodiments, the second insulator 1114 is a covercoat layer, such as a polyimide insulator. Those skilled in the art will appreciate that other dimensions and materials may be used to meet desired design characteristics.

[0020] FIG. 12 shows a diagram of an embodiment of a bimorph actuator according to an embodiment. The embodiment as shown in FIG. 12 includes a central feed 1204 for applying power. Power is supplied at the center of the SMA material 1202 (wire or ribbon) as described herein. The ends of the SMA material 1202 are grounded to the beam 1206 or base metal as a return at the end pads 1203. The end pads 1203 are electrically isolated from the remainder of the contact layer 1214. According to embodiments, the proximity of the beam 1206 or base metal to the SMA material 1202, such as an SMA wire, along its entire length allows the wire to cool faster when the current is turned off, i.e., the bimorph actuator is deactivated. This results in faster wire deactivation and actuator response times. The thermal profile of the SMA wire or ribbon is improved. For example, the thermal profile is more uniform so that a higher total current can be reliably delivered to the wire. Without a uniform heat sink, portions of the wire, such as the center region, can become overheated and damaged, thus necessitating reduced current and reduced actuation for reliable operation. The center feed 1204 provides the benefits of more rapid wire activation / actuation of the SMA material 1202 (faster heating) and reduced power consumption (lower resistive path length) for faster response times. This allows for faster actuator actuation and higher frequency of movement.

[0021] As shown in FIG. 12, the beam 1206 includes a central metal 1208 that is isolated from the remainder of the beam 1206 to form a central feed 1204. An insulator 1210 as described herein is disposed over the beam 1206. The insulator 1210 is configured with one or more openings or vias 1212 to provide electrical access to the beam 1206, for example, to couple a ground section 1214b of a contact layer, and to provide contact to the central metal 1208 to form the central feed 1204. The contact layer 1214 as described herein includes a power section 1214a and a ground section 1214b to provide actuation / control signals to the bimorph actuator via a power supply contact 1216 and a ground contact 1218, according to some embodiments. A covercoat layer 1220 as described herein is disposed over the contact layer 1214 to electrically insulate the contact layer except for portions of the contact layer 1214 (e.g., one or more contacts) to which electrical coupling is desired.

[0022] FIG. 13 illustrates an end pad cross section of a bimorph actuator according to one embodiment as shown in FIG. 12. As described above, the end pad 1203 is electrically isolated from the remainder of the contact layer 1214 by a gap 1222 formed between the end pad 1203 and the contact layer 1214. According to some embodiments, the gap is formed using an etching technique, such as techniques known in the art. The end pad 1203 includes a via section 1224 configured to electrically couple the end pad 1203 with the beam 1206. The via section 1224 is formed in a via 1212 formed in the insulator 1210. The SMA material 1202 is electrically coupled to the end pad 1213. The SMA material 1202 can be electrically coupled to the end pad 1213 using techniques including, but not limited to, soldering, resistance welding, laser welding, and direct plating.

[0023] Figure 14 shows a cross section of a central feed of a bimorph actuator according to one embodiment as shown in Figure 12. The central feed 1204 is electrically coupled to a power source through a contact layer 1214 and is electrically and thermally coupled to a central metal 1208 by a via section 1226 of the central feed 1204 formed in a via 1212 formed in an insulator 1210.

[0024] The actuators described herein may be used to form actuator assemblies using multiple buckles and / or multiple bimorph actuators. According to one embodiment, the actuators may be stacked on top of each other to increase the stroke distance that can be achieved.

[0025] 15 shows an exploded view of an SMA actuator including two buckle actuators, according to one embodiment. The two buckle actuators 1302, 1304 are positioned relative to one another to oppose one another using their motion, according to embodiments described herein. In various embodiments, the two buckle actuators 1302, 1304 are configured to move in an inverse relationship to one another to position the lens carriage 1306. For example, the first buckle actuator 1302 is configured to receive an inverse power signal of a power signal sent to the second buckle actuator 1304.

[0026] 16 illustrates an SMA actuator including two buckle actuators, according to one embodiment. The buckle actuators 1302, 1304 are configured such that the buckle arms 1310, 1312 of each buckle actuator 1302, 1304 face each other and the sliding bases 1314, 1316 of each buckle actuator 1302, 1304 are the outer surfaces of the two buckle actuators. The hammock portion 1308 of each SMA actuator 1302, 1304 is configured to support an object acted upon by one or more buckle actuators 1302, 1304, such as a portion of a lens carriage 1306 that is moved by the buckle actuators, using techniques such as those described herein, according to various embodiments.

[0027] FIG. 17 shows a side view of an SMA actuator including two buckle actuators according to one embodiment, showing the orientation of the SMA wires 1318 that will move an object such as a lens carriage in the positive z or upward direction.

[0028] FIG. 18 shows a side view of an SMA actuator including two buckle actuators according to one embodiment, illustrating the orientation of the SMA wires 1318 that will move an object such as a lens carriage in the negative z or downward direction.

[0029] 19 shows an exploded view of an assembly including an SMA actuator including two buckle actuators, according to one embodiment. The buckle actuators 1902, 1904 are configured such that the buckle arms 1910, 1912 of each buckle actuator 1902, 1904 are the outer surfaces of the two buckle actuators, and the sliding bases 1914, 1916 of each buckle actuator 1902, 1904 face each other. The hammock portion 1908 of each SMA actuator 1902, 1904 is configured to support an object acted upon by one or more buckle actuators 1902, 1904, for example, a portion of the lens carriage 1906 that is moved by the buckle actuators using techniques such as those described herein, according to various embodiments. In some embodiments, the SMA actuator includes a base portion 1918 configured to receive the second buckle actuator 1904. The SMA actuator may also include a cover portion 1920. FIG. 20 illustrates an SMA actuator including two buckle actuators according to one embodiment, including a base portion and a cover portion.

[0030] 21 illustrates an SMA actuator including two buckle actuators, according to one embodiment. In some embodiments, the buckle actuators 1902, 1904 are positioned relative to one another such that the hammock portion 1908 of the first buckle actuator 1902 is rotated approximately 90 degrees from the hammock portion of the second buckle actuator 1904. The 90 degree configuration allows for pitch and roll rotation of an object such as the lens carriage 1906, which allows for better control over the movement of the lens carriage 1906. In various embodiments, a differential power signal is applied to the SMA wires of each buckle actuator pair, thereby providing pitch and roll rotation of the lens carriage for tilt OIS operation.

[0031] In an embodiment of an SMA actuator that includes two buckle actuators, a return spring is not required. The use of two buckle actuators can improve / reduce hysteresis when using SMA wire resistance for position feedback. Counterforce SMA actuators that include two buckle actuators have less hysteresis than those that include return springs, thus aiding in more accurate position control. In some embodiments, such as the embodiment shown in FIG. 22, an SMA actuator that includes two buckle actuators 2202, 2204 uses differential power to the left SMA wire 2218a and the right SMA wire 2218b of each buckle actuator 2202, 2204 to provide two-axis tilt. For example, the left SMA wire 2218a is actuated with a higher power than the right SMA wire 2218b. This causes the left side of the lens carriage 2206 to move downwards and the right side to move upwards (tilt). In some embodiments, the SMA wires of the first buckle actuator 2202 are held with equal force and act as a fulcrum for the SMA wires 2218a, 2218b to push differentially to cause tilt motion. Reversing the power signal applied to the SMA wires, for example applying equal power to the SMA wires of the second buckle actuator 2202 and using differential power to the left SMA wire 2218a and right SMA wire 2218b of the second buckle actuator 2204, results in tilt of the lens carriage 2206 in the other direction. This allows an object such as a lens carrier to be tilted in either axis of motion, or for better dynamic tilt, any tilt between the lens and the sensor can be adjusted, which translates into better image quality across all pixels.

[0032] 23 shows an SMA actuator including two buckle actuators and a coupler, according to one embodiment. The SMA actuator includes two buckle actuators as described herein. A first buckle actuator 2302 is configured to couple with a second buckle actuator 2304 using a coupler, e.g., coupler ring 2305. The buckle actuators 2302, 2304 are positioned relative to each other such that a hammock portion 2308 of the first buckle actuator 2302 is rotated approximately 90 degrees from a hammock portion 2309 of the second buckle actuator 2304. A payload to be moved, such as a lens or lens assembly, is attached to a lens carriage 2306 configured to be positioned on a slide base of the first buckle actuator 2302.

[0033] In various embodiments, equal power can be applied to the SMA wires of the first buckle actuator 2302 and the second buckle actuator 2304. This can maximize the z-stroke of the SMA actuator in the positive z-direction. In some embodiments, the stroke of the SMA actuator can have a z-stroke that is more than twice as long as the stroke of the other SMA actuators, including the two buckle actuators. In some embodiments, an additional spring can be added to bias the two bucklers together to help push down the actuator assembly and payload when the power signal is removed from the SMA actuator. Equal and opposite power signals can be applied to the SMA wires of the first buckle actuator 2302 and the second buckle actuator 2304. This can allow the SMA actuator to move in the positive z-direction by the buckle actuator and in the negative z-direction by the buckle actuator, allowing precise control of the position of the SMA actuator. Additionally, equal and opposite power signals (differential power signals) can be applied to the left and right SMA wires of the first buckle actuator 2302 and the second buckle actuator 2304 to tilt an object such as the lens carriage 2306 in at least one of two axes.

[0034] An embodiment of an SMA actuator including two buckle actuators and a coupler, such as that shown in FIG. 23, can be combined with additional buckle actuators and multiple buckle actuator pairs to achieve a desired stroke greater than the stroke of a single SMA actuator.

[0035] FIG. 24 shows an exploded view of an SMA system including an SMA actuator including a buckle actuator with a laminate hammock, according to one embodiment. As described herein, the SMA system is configured in some embodiments to be used in conjunction with one or more camera lens elements as an autofocus drive. As shown in FIG. 24, the SMA system includes a return spring 2403 configured to move the lens carriage 2406 in the opposite direction to the z-stroke direction when tension in the SMA wire 2408 decreases as the SMA wire is deactivated, according to various embodiments. The SMA system for some embodiments includes a housing 2409 configured to receive the return spring 2403 and act as a sliding bearing to guide the lens carriage in the z-stroke direction. The housing 2409 is also configured to be disposed on a buckle actuator 2402. The buckle actuator 2402 includes a slide base 2401 similar to that described herein. The buckle actuator 2402 includes a buckle arm 2404 coupled to a hammock portion, such as a laminate hammock 2406 formed of a laminate. The buckle actuator 2402 also includes an SMA wire attachment structure, such as a laminated crimp connection 2412.

[0036] As shown in Figure 24, the sliding base 2401 is placed on an optional adapter plate 2414. The adapter plate is configured to couple the SMA system or buckle actuator 2402 to another system, such as an OIS, additional SMA systems, or other components. Figure 25 shows an SMA system 2501 including an SMA actuator that includes a buckle actuator 2402 with a laminate hammock, according to one embodiment.

[0037] FIG. 26 illustrates a buckle actuator including a laminate hammock according to one embodiment. The buckle actuator 2402 includes a buckle arm 2404. The buckle arm 2404 is configured to move in the z-axis when an SMA wire 2412 is actuated and deactuated as described herein. The SMA wire 2408 is attached to the buckle actuator using a laminated crimp connection 2412. According to the embodiment shown in FIG. 26, the buckle arms 2404 are coupled together via a central portion, such as a laminate hammock 2406. The laminate hammock 2406 is configured to support an object actuated by the buckle actuator, for example, a portion of a lens carriage moved by the buckle actuator using techniques such as those described herein, according to various embodiments.

[0038] FIG. 27 illustrates a laminate hammock for an SMA actuator according to one embodiment. In some embodiments, the material of the laminate hammock 2406 is a low stiffness material and therefore does not resist actuation movement. For example, the laminate hammock 2406 is formed using a copper layer disposed on a first polyimide layer and a second polyimide layer disposed on the copper. In some embodiments, the laminate hammock 2406 is formed on the buckle arm 2404 using deposition and etching techniques, such as techniques known in the art. In other embodiments, the laminate hammock 2406 is formed separately from the buckle arm 2404 and attached to the buckle arm 2404 using techniques such as welding, adhesives, and other techniques known in the art. In various embodiments, glue or other adhesives are used on the laminate hammock 2406 to ensure that the buckler arm 2404 remains in place relative to the lens carriage.

[0039] 28 illustrates a laminated crimp connection for an SMA actuator according to one embodiment. The laminated crimp connection 2412 is configured to attach an SMA wire 2408 to a buckle actuator and form an electrical circuit interface with the SMA wire 2408. In various embodiments, the laminated crimp connection 2412 includes a laminate formed from one or more layers of insulation and one or more layers of conductive layers formed over the crimp.

[0040] For example, a polyimide layer is disposed on at least a portion of the stainless steel portion that forms the crimp 2413. A conductive layer, such as copper, is then disposed on the polyimide layer, and the conductive layer is electrically coupled to one or more signal traces 2415 disposed on the buckle actuator. The SMA wire is also electrically contacted with the conductive layer by deforming the crimp to contact the SMA wire in the crimp. The conductive layer, coupled with the one or more signal traces, is thus used to apply a power signal to the SMA wire using techniques such as those described herein. In some embodiments, a second polyimide layer is formed on the conductive layer in areas where the conductive layer does not contact the SMA wire. In some embodiments, the laminated crimp connection 2412 is formed on the crimp 2413 using deposition and etching techniques, such as those known in the art. In other embodiments, the laminated crimp connection 2412 and one or more electrical traces are formed separately from the crimp 2413 and buckle actuator and attached to the crimp 2412 and buckle actuator using techniques such as welding, adhesives, and other techniques known in the art.

[0041] Figure 29 shows an SMA actuator including a buckle actuator with a laminate hammock. As shown in Figure 29, when a power signal is applied, the SMA wire contracts or shortens, moving the buckle arms and laminate hammock in the positive z direction. The laminate hammock in contact with an object then moves the object, such as a lens carriage, in the positive z direction. When the power signal is reduced or removed, the SMA wire expands, moving the buckle arms and laminate hammock in the negative z direction.

[0042] FIG. 30 shows an exploded view of an SMA system including an SMA actuator including a buckle actuator, according to one embodiment. As described herein, the SMA system is configured in some embodiments to be used in conjunction with one or more camera lens elements as an autofocus drive. As shown in FIG. 30, the SMA system includes a return spring 3003 configured to move the lens carriage 3005 in the opposite direction to the z-stroke direction when tension in the SMA wire 3008 decreases as the SMA wire is deactivated, according to various embodiments. The SMA system includes a stiffener 3000 disposed on the return spring 3003, in some embodiments. The SMA system for some embodiments includes a housing 3009 formed from two parts configured to receive the return spring 3003 and act as a sliding bearing to guide the lens carriage in the z-stroke direction. The housing 3009 is also configured to be disposed on the buckle actuator 3002. The buckle actuator 3002 is formed from two parts, including a slide base 3001 similar to that described herein. According to some embodiments, as current flows through the wires through the slide base 3001 portions, the slide base 3001 is split to electrically isolate the two sides (e.g., one side is ground and the other side is power).

[0043] The buckle actuator 3002 includes buckle arms 3004. Each pair of buckle actuators 3002 is formed on a separate portion of the buckle actuator 3002. The buckle actuator 3002 also includes an SMA wire attachment structure, such as a resistance weld wire crimp 3012. The SMA system optionally includes a flex circuit 3020 for electrically coupling the SMA wire 3008 to one or more control circuits.

[0044] As shown in Figure 30, the sliding base 3001 is placed on an optional adapter plate 3014. The adapter plate is configured to couple the SMA system or buckle actuator 3002 to another system, such as an OIS, additional SMA systems, or other components. Figure 31 shows an SMA system 3101 including an SMA actuator that includes a buckle actuator 3002, according to one embodiment.

[0045] Figure 32 includes an SMA actuator including a buckle actuator, according to one embodiment. The buckle actuator 3002 includes a buckle arm 3004. The buckle arm 3004 is configured to move in the z-axis when an SMA wire 3012 is actuated and deactuated as described herein. An SMA wire 2408 is attached to a resistance weld wire crimp 3012. According to the embodiment shown in Figure 32, the buckle arm 3004 is configured to mate with an object, such as a lens carriage without a center portion, using a two yoke capture joint.

[0046] FIG. 33 shows the two yoke capture joints of a pair of buckle arms of an SMA actuator, according to one embodiment. FIG. 33 also shows the plating pads used to attach the optional flex circuit to the sliding base. In some embodiments, the plating pads are formed using gold. FIG. 34 shows the resistance weld crimps of an SMA actuator, according to one embodiment, used to attach the SMA wire to the buckle actuator. In some embodiments, glue or adhesive can also be placed over the welds to aid in mechanical strength and act as a fatigue strain relief during operation and shock loading.

[0047] FIG. 35 shows an SMA actuator that includes a buckle actuator with two yoke capture joints. As shown in FIG. 35, when a power signal is applied, the SMA wire contracts or shortens, moving the buckle arm in the positive z direction. The two yoke capture joints are in contact with an object, which in turn moves the object, such as a lens carriage, in the positive z direction. When the power signal is reduced or removed, the SMA wire expands, moving the buckle arm in the negative z direction. The yoke capture feature ensures that the buckle arm remains in the correct position relative to the lens carriage.

[0048] FIG. 36 illustrates an SMA bimorph liquid lens according to one embodiment. The SMA bimorph liquid lens 3501 includes a liquid lens subassembly 3502, a housing 3504, and a circuit with an SMA actuator 3506. In various embodiments, the SMA actuator includes four bimorph actuators 3508, such as the embodiments described herein. The bimorph actuators 3508 are configured to push a shaped ring 3510 located on a flexible membrane 3512. The ring distorts the membrane 3512 / liquid 3514 to change the optical path through the membrane 3512 / liquid 3514. A liquid containment ring 3516 is used to contain the liquid 3514 between the membrane 3512 and the lens 3518. Equal forces from the bimorph actuators change the focus of the image in the Z direction (perpendicular to the lens), thereby allowing it to function as an autofocus. The differential force from the bimorph actuator 3508 can move the beam in the X and Y directions, thereby allowing it to function as an optical image stabilization mechanism according to some embodiments. Both OIS and AF functions can be achieved simultaneously with appropriate control to each actuator. In some embodiments, three actuators are used. The circuit with the SMA actuator 3506 includes one or more contacts 3520 for control signals to activate the SMA actuators. According to some embodiments including four SMA actuators, the circuit with the SMA actuator 3506 includes four power circuit control contacts for each SMA actuator and a common return contact.

[0049] Figure 37 shows a perspective view of an SMA bimorph liquid lens according to one embodiment. Figure 38 shows a cross-sectional and bottom view of an SMA bimorph liquid lens according to one embodiment. FIG. 39 illustrates an SMA system including an SMA actuator 3902 with bimorph actuators according to one embodiment. The SMA actuator 3902 includes four bimorph actuators using the techniques described herein. As shown in FIG. 40, which illustrates an SMA actuator 3902 with bimorph actuators according to one embodiment, two of the bimorph actuators are configured as positive z-stroke actuators 3904 and two are configured as negative z-stroke actuators 3906. The opposing actuators 3906, 3904 are configured to control movement in both directions over the entire stroke range. This allows the control code to be adjusted to compensate for tilt. In various embodiments, two SMA wires 3908 attached to the top of the component allow for positive z-stroke displacement. Two SMA wires attached to the bottom of the component allow for negative z-stroke displacement. In some embodiments, each bimorph actuator is attached to an object, such as a lens carriage 3910, using a tab to engage the object. The SMA system includes a top spring 3912 configured to provide stability to the lens carriage 3910 in an axis perpendicular to the z-stroke axis, e.g., in the x-axis and y-axis directions. Additionally, a top spacer 3914 is configured to be disposed between the top spring 3912 and the SMA actuator 3902. A bottom spacer 3916 is disposed between the SMA actuator 3902 and a bottom spring 3918. The bottom spring 3918 is configured to provide stability to the lens carriage 3910 in an axis perpendicular to the z-stroke axis, e.g., in the x-axis and y-axis directions. The bottom spring 3918 is configured to be disposed on a base 3920 as described herein.

[0050] 41 shows the length 4102 of the bimorph actuator 4103 and the location of the bond pads 4104 for the SMA wire 4206 to extend the wire length beyond the bimorph actuator. To increase the stroke and force, a longer wire is used than the bimorph actuator. Thus, the extension length 4108 of the SMA wire 4206 beyond the bimorph actuator 4103 is used to set the stroke and force of the bimorph actuator 4103.

[0051] FIG. 42 shows an exploded view of an SMA system including an SMA bimorph actuator 4202 according to one embodiment. The SMA system is configured to create one or more electrical circuits that independently power the SMA wires using separate metal materials and non-conductive adhesives according to various embodiments. Some embodiments include four bimorph actuators as described herein without AF size effects. Two of the bimorph actuators are configured as positive z-stroke actuators and two are configured as negative z-stroke actuators. FIG. 43 shows an exploded view of a small portion of an SMA actuator according to one embodiment. The small portion includes a base 4304 having a negative actuator signal connection 4302, a bimorph actuator 4306. The negative actuator signal connection 4302 includes a wire bond pad 4308 for connecting the SMA wires of the bimorph actuator 4306 using techniques such as those described herein. The negative actuator signal connection 4302 is attached to the base 4304 using an adhesive layer 4310. The subsection also includes a positive actuator signal connection 4314 having a wire bond pad 4316 for connecting the SMA wire 4312 of the bimorph actuator 4306 using techniques such as those described herein. The positive actuator signal connection 4314 is attached to the base 4304 using an adhesive layer 4318. Each of the base 4304, the negative actuator signal connection 4302, and the positive actuator signal connection 4314 are formed of a metal, for example stainless steel. Connection pads 4322 on each of the base 4304, the negative actuator signal connection 4302, and the positive actuator signal connection 4314 are configured to electrically couple control signals and ground for actuating the bimorph actuator 4306 using techniques such as those described herein. In some embodiments, the connection pads 4322 are gold plated. FIG. 44 illustrates a subsection of an SMA actuator according to one embodiment. In some embodiments, gold plated pads are formed on the stainless steel layer for solder bonding or other known electrical termination methods.In addition, the formed wire bond pads are used for signal joints to electrically couple SMA wires for power signals.

[0052] FIG. 45 shows a 5-axis sensor shift system according to an embodiment. The 5-axis sensor shift system is configured to move an object, such as an image sensor, in 5 axes relative to one or more lenses. This includes X / Y / Z translation and pitch / roll tilt. Optionally, the system is configured to use only 4 axes with X / Y translation and pitch / roll tilt, along with a separate AF on top to perform Z motion. Other embodiments include a 5-axis sensor shift system configured to move one or more lenses relative to the image sensor. In some embodiments, a static lens stack is mounted on the top cover and inserted inside the ID (not touching the orange movable carriage inside).

[0053] FIG. 46 shows an exploded view of a five-axis sensor shifting system according to one embodiment. The five-axis sensor shifting system includes two circuit components: a flexible sensor circuit 4602, a bimorph actuator circuit 4604, and 8-12 bimorph actuators 4606 built on the bimorph circuit components using techniques such as those described herein. The five-axis sensor shifting system includes a moveable carriage 4608 configured to hold one or more lenses and an outer housing 4610. The bimorph actuator circuit 4604 includes 8-12 SMA actuators as described herein according to one embodiment. The SMA actuators are configured to move the moveable carriage 4608 in five axes, such as x-direction, y-direction, z-direction, pitch, and roll similar to other five-axis systems described herein.

[0054] FIG. 47 shows an SMA actuator with a bimorph actuator integrated into the circuit for all of the movements, according to one embodiment. An embodiment of the SMA actuator may include 8-12 bimorph actuators 4606. However, other embodiments may include more or less. FIG. 48 shows an SMA actuator 4802 with a bimorph actuator integrated into the circuit for all of the movements, according to one embodiment, partially formed to fit inside a corresponding outer housing 4804. FIG. 49 shows a cross section of a 5-axis sensor shifting system, according to one embodiment.

[0055] Figure 50 shows an SMA actuator 5002 according to one embodiment, including a bimorph actuator. The SMA actuator 5002 is configured to move an image sensor, lens, or other various payloads in the x and y directions using four side-mounted SMA bimorph actuators 5004. Figure 51 shows a top view of an SMA actuator, including a bimorph actuator, that has moved an image sensor, lens, or other various payloads to different x and y positions.

[0056] FIG. 52 shows an SMA actuator including a bimorph actuator 5202 according to one embodiment configured as a box bimorph autofocus. Four top- and bottom-mounted SMA bimorph actuators as described herein are configured to move together to generate z-stroke motion for autofocus operation. FIG. 53 shows an SMA actuator including a bimorph actuator according to one embodiment, where two top-mounted bimorph actuators 5302 are configured to push one or more lenses down. FIG. 54 shows an SMA actuator including a bimorph actuator according to one embodiment, where two bottom-mounted bimorph actuators 5402 are configured to push one or more lenses up. FIG. 55 shows an SMA actuator including a bimorph actuator according to one embodiment, where four top- and bottom-mounted SMA bimorph actuators 5502 as described herein are used to move one or more lenses to generate tilt motion.

[0057] FIG. 56 shows an SMA system including an SMA actuator according to an embodiment, including a bimorph actuator configured as a two-axis lens shift OIS. In some embodiments, the two-axis lens shift OIS is configured to move the lens in the X-axis / Y-axis. In some embodiments, the Z-axis movement comes from a separate AF as described herein. The four bimorph actuators push on the sides of the autofocus for OIS operation. FIG. 57 shows an exploded view of an SMA system including an SMA actuator 5802 according to an embodiment, including a bimorph actuator 5806 configured as a two-axis lens shift OIS. FIG. 58 shows a cross section of an SMA system including an SMA actuator 5802 according to an embodiment, including a bimorph actuator 5806 configured as a two-axis lens shift OIS. FIG. 59 shows a box bimorph actuator 5802 according to an embodiment for use in an SMA system configured as a two-axis lens shift OIS in an as-manufactured state prior to being molded to fit within the system. Such a system can be configured to have a high OIS stroke OIS (e.g., + / - 200 μm or more). Moreover, such embodiments are configured to have a wide range of motion and good OIS dynamic tilt using four plain bearings, such as POM plain bearings.Embodiments are configured to easily integrate with AF designs (e.g., VCM or SMA).

[0058] FIG. 60 shows an SMA system including an SMA actuator according to an embodiment including a bimorph actuator configured as a 5-axis lens shift OIS and autofocus. In some embodiments, the 5-axis lens shift OIS and autofocus is configured to move the lens in the X-axis / Y-axis / Z-axis. In some embodiments, the pitch and yaw axis motion is for dynamic tilt adjustment capabilities. Eight bimorph actuators are used to provide autofocus and OIS operation using the techniques described herein. FIG. 61 shows an exploded view of an SMA system including an SMA actuator 6202 according to an embodiment including a bimorph actuator 6204 according to an embodiment configured as a 5-axis lens shift OIS and autofocus. FIG. 62 shows a cross section of an SMA system including an SMA actuator 6202 according to an embodiment including a bimorph actuator 6204 configured as a 5-axis lens shift OIS and autofocus. FIG. 63 shows a box bimorph actuator 6202 according to an embodiment for use in an SMA system configured as a 5-axis lens shift OIS and autofocus in an as-manufactured state prior to being molded to fit within the system. Such systems can be configured to have high OIS stroke (e.g., + / - 200 μm or greater) and high autofocus stroke (e.g., 400 μm or greater). Additionally, such embodiments can accommodate any tilt and eliminate the need for a separate autofocus assembly.

[0059] FIG. 64 shows an SMA system including an SMA actuator according to one embodiment, including a bimorph actuator configured as an outward push box. In some embodiments, the bimorph actuator assembly is configured to be placed around an object, such as a lens carriage. Since the circuit assembly is moving with the lens carriage, there is a flexible section for low X / Y / Z stiffness. The tail pad of the circuit is static. The outward push box can be configured for both four bimorph actuators or eight bimorph actuators. Thus, the outward push box can be configured as four bimorph actuators on the sides for OIS with motion in the X and Y axes. The outward push box can be configured as four bimorph actuators on the top and bottom for autofocus with motion in the z axis. The outward push box can be configured as eight bimorph actuators on the top, bottom, and sides for OIS and autofocus with motion in the x, y, and z axes and capable of three-axis tilt (pitch / roll / yaw). FIG. 65 shows an exploded view of an SMA system including an SMA actuator 6602 according to one embodiment including a bimorph actuator 6604 configured as an outwardly pushing box. The SMA actuator is thus configured such that the bimorph actuator acts on the outer housing 6504 to move the lens carriage 6506 using the techniques described herein. FIG. 66 shows an SMA system including an SMA actuator 6602 according to one embodiment including a bimorph actuator configured as an outwardly pushing box partially molded to receive the lens carriage 6604. FIG. 67 shows an SMA system including an SMA actuator 6602 according to one embodiment including a bimorph actuator 6604 configured as an outwardly pushing box in the as-manufactured state prior to being molded to fit within the system.

[0060] FIG. 68 shows an SMA system including an SMA actuator 6802 according to an embodiment, including a bimorph actuator configured as a three-axis sensor-shifting OIS. In some embodiments, the z-axis motion comes from a separate autofocus system. The four bimorph actuators are configured to push on the sides of the sensor carriage 6804 to provide motion for the OIS using techniques described herein. FIG. 69 shows an exploded view of an SMA including an SMA actuator 6802 according to an embodiment, including a bimorph actuator configured as a three-axis sensor-shifting OIS. FIG. 70 shows a cross-section of an SMA system including an SMA actuator 6802 according to an embodiment, including a bimorph actuator 6806 configured as a three-axis sensor-shifting OIS. FIG. 71 shows components of a box bimorph actuator 6802 according to an embodiment for use in an SMA system configured as a three-axis sensor-shifting OIS in an as-manufactured state prior to being molded to fit within the system. FIG. 72 shows a flexible sensor circuit for use in an SMA system configured as a three-axis sensor-shifting OIS according to an embodiment. Such systems can be configured to have high OIS stroke (e.g., + / - 200 μm or more) and high autofocus stroke (e.g., 400 μm or more). Furthermore, such embodiments are configured to have a wide range of two-axis motion and good OIS dynamic tilt using four plain bearings, such as POM plain bearings. Embodiments are configured to easily integrate with AF designs (e.g., VCM or SMA).

[0061] FIG. 73 shows an SMA system including an SMA actuator 7302 according to one embodiment including a bimorph actuator 7304 configured as a 6-axis sensor-shifting OIS and autofocus. In some embodiments, the 6-axis sensor-shifting OIS and autofocus is configured to move the lens in the X / Y / Z / pitch / yaw / roll axes. In some embodiments, the pitch and yaw axis motion is for dynamic tilt adjustment capabilities. Eight bimorph actuators are used to provide autofocus and OIS operation using the techniques described herein. FIG. 74 shows an exploded view of an SMA system including an SMA actuator 7402 according to one embodiment including a bimorph actuator 7404 configured as a 6-axis sensor-shifting OIS and autofocus. FIG. 75 shows a cross section of an SMA system including an SMA actuator 7402 according to one embodiment including a bimorph actuator configured as a 6-axis sensor-shifting OIS and autofocus. FIG. 76 shows a box bimorph actuator 7402 according to one embodiment for use in an SMA system configured as a 6-axis sensor-shifting OIS and autofocus in an as-manufactured state prior to being molded to fit within the system. FIG. 77 shows a flexible sensor circuit for use in an SMA system according to one embodiment configured as a 3-axis sensor-shifting OIS. Such a system can be configured to have a high OIS stroke (e.g., + / - 200 μm or more) and a high autofocus stroke (e.g., 400 μm or more). Additionally, such an embodiment can accommodate any tilt and eliminate the need for a separate autofocus assembly.

[0062] FIG. 78 shows an SMA system including an SMA actuator according to an embodiment, including a bimorph actuator configured as a 2-axis camera tilt OIS. In some embodiments, the 2-axis camera tilt OIS is configured to move the camera in the pitch / yaw axis. Four bimorph actuators are used to push the top and bottom of the autofocus for full camera movement for the OIS pitch and yaw motion using the techniques described herein. FIG. 79 shows an exploded view of an SMA system including an SMA actuator 7902 according to an embodiment, including a bimorph actuator 7904 configured as a 2-axis camera tilt OIS. FIG. 80 shows a cross section of an SMA system including an SMA actuator according to an embodiment, including a bimorph actuator configured as a 2-axis camera tilt OIS. FIG. 81 shows a box bimorph actuator according to an embodiment for use in an SMA system configured as a 2-axis camera tilt OIS in an as-manufactured state prior to being molded to fit within the system. FIG. 82 shows a flexible sensor circuit for use in an SMA system configured as a 2-axis camera tilt OIS according to an embodiment. Such systems can be configured to have a high OIS stroke (e.g., + / - 3 degrees or more).Embodiments are configured to easily integrate with autofocus ("AF") designs (e.g., VCM or SMA).

[0063] FIG. 83 shows an SMA system including an SMA actuator according to an embodiment, including a bimorph actuator configured as a 3-axis camera tilt OIS. In some embodiments, a 2-axis camera tilt OIS is configured to move the camera in pitch / yaw / roll axes. Four bimorph actuators are used to push the top and bottom of the autofocus for full camera movement for OIS pitch and yaw movement, using the techniques described herein, and four bimorph actuators are used to push the sides of the autofocus for full camera movement for OIS roll movement, using the techniques described herein. FIG. 84 shows an exploded view of an SMA system including an SMA actuator 8402 according to an embodiment, including a bimorph actuator 8404 configured as a 3-axis camera tilt OIS. FIG. 85 shows a cross-section of an SMA system including an SMA actuator according to an embodiment, including a bimorph actuator configured as a 3-axis camera tilt OIS. FIG. 86 shows a box bimorph actuator for use in an SMA system according to an embodiment configured as a 3-axis camera tilt OIS, in an as-manufactured state prior to being molded to fit within the system. FIG. 87 shows a flexible sensor circuit for use with an SMA system according to one embodiment configured as a 3-axis camera tilt OIS. Such a system can be configured to have a high OIS stroke (e.g., + / - 3 degrees or more). The embodiment is configured to easily integrate with AF designs (e.g., VCM or SMA).

[0064] 88 shows exemplary dimensions of a bimorph actuator of an SMA actuator according to an embodiment. While the dimensions are a preferred embodiment, one skilled in the art will understand that other dimensions can be used based on the desired characteristics of the SMA actuator.

[0065] FIG. 89 illustrates a lens system for a folded camera according to one embodiment. The folded camera includes a folded lens 8902 configured to bend light into a lens system 8901 that includes one or more lenses 8903a-d. In some embodiments, the folded lens is any one or more of a prism and a lens. The lens system 8901 is configured to have a principal axis 8904 that is at an angle to a transmission axis 8906 that is parallel to the light's direction of travel before the light reaches the folded lens 8902. For example, folded cameras are used in camera phone systems to reduce the height of the lens system 8901 in the direction of the transmission axis 8906.

[0066] An embodiment of the lens system includes one or more liquid lenses as described herein. The embodiment illustrated in FIG. 89 includes two liquid lenses 8903b, 8903d as described herein. The one or more liquid lenses 8903b, 8903d are configured to be actuated using techniques such as those described herein. The liquid lenses are actuated using actuators including, but not limited to, buckle actuators, bimorph actuators, and other SMA actuators. FIG. 108 shows a liquid lens actuated using a buckle actuator 60, according to one embodiment. The liquid lens includes a molded ring coupler 64, a liquid lens assembly 61, one or more buckle actuators 60 as described herein, a sliding base 65, and a base 62. The one or more buckle actuators 60 are configured to move the molded ring / coupler 64 to change the shape of the flexible membrane of the liquid lens assembly 61 to move or shape the light beam, for example as described herein. In some embodiments, three or four actuators are used. A liquid lens may be configured to function as an autofocus or optical image stabilization mechanism, alone or in combination with other lenses. A liquid lens may also be configured to otherwise direct an image onto an image sensor.

[0067] 90 illustrates several embodiments of a lens system 9001 including liquid lenses 9002a-h for focusing an image onto an image sensor 9004. As illustrated, the liquid lenses 9002a-h may include any lens shape and may be configured to be dynamically configured to adjust the light path through the lens using techniques such as those described herein.

[0068] The lens system for the folded camera is configured to include an actuated folded lens 9100. One example of an actuated folded lens is a prism tilt as shown in FIG. 91. In the example shown in FIG. 91, the folded lens is a prism 9102 disposed on an actuator 9104. The actuators include, but are not limited to, SMA actuators, including those described herein. In some embodiments, the prism tilt is disposed on an SMA actuator, including four bimorph actuators 9106, as described herein. The actuated folded lens 9100 is configured as an optical image stabilization mechanism, according to some embodiments, using techniques such as those described herein. For example, the actuated folded lens is configured to include an SMA system as shown in FIG. 39. Another example of an actuated folded lens can include an SMA actuator as illustrated in FIG. 21. However, the folded lens may also include other actuators.

[0069] FIG. 92 illustrates a bimorph arm with an offset according to one embodiment. Bimorph arm 9201 includes a bimorph beam 9202 with a shaped offset 9203. The shaped offset 9203 increases the mechanical advantage and generates a higher force than a bimorph arm without an offset. According to some embodiments, the depth of offset 9204 (also referred to herein as bending plane z offset 9204) and the length of offset 9206 (also referred to herein as trough width 9206) are configured to define the characteristics of the bimorph arm, such as the peak force. For example, the graph in FIG. 106 illustrates the relationship between bending plane z offset 9204, trough width 9206, and peak force of a bimorph beam 9202 according to one embodiment.

[0070] The bimorph arm includes one or more SMA materials, such as SMA ribbons or wires 9210, as described herein. The SMA material is attached to the beam using techniques such as those described herein. In some embodiments, the SMA material, such as SMA wires 9210, is attached to the fixed end 9212 of the bimorph arm and the load point end 9214 of the bimorph arm such that a formed offset 9203 is between the ends to which the SMA material is attached. In various embodiments, the ends of the SMA material are electrically and mechanically coupled to contacts configured to provide current to the SMA material, using techniques such as those known in the art. Bimorph arms with offsets can be included in SMA actuators and systems as described herein.

[0071] 93 illustrates a bimorph arm with an offset and limiter, according to one embodiment. The bimorph arm 9301 includes a bimorph beam 9302 with a shaped offset 9303 and a limiter 9304 adjacent to the shaped offset 9303. The offset 9303 increases the mechanical advantage and generates a higher force than a bimorph arm 9301 without an offset, and the limiter 9304 prevents motion of the arm away from the free load point end 9306 of the bimorph actuator. The bimorph arm 9301 with the shaped offset 9303 and limiter 9304 can be included in SMA actuators and systems as described herein. The bimorph arm 9301 includes one or more SMA materials, such as SMA ribbons or SMA wires 9308 as described herein, attached to the bimorph arm 9301 using techniques such as those described herein.

[0072] FIG. 94 illustrates a bimorph arm with an offset and limiter, according to one embodiment. The bimorph arm 9401 includes a bimorph beam 9402 with a formed offset 9403 and a limiter 9404 adjacent the formed offset 9403. The limiter 9404 is formed as part of a base 9406 for the bimorph arm 9401. The base 9406 is configured to receive the bimorph arm 9401 and includes a recess 9408 configured to receive an offset portion of the bimorph beam. A bottom of the recess is configured as the limiter 9404 adjacent the formed offset 9403. The base 9406 may also include one or more portions 9410 configured to support a portion of the bimorph arm when the bimorph arm is not actuated. The bimorph arm 9401 with the formed offset 9403 and limiter 9404 may be included in SMA actuators and systems as described herein. The bimorph arm 9401 includes one or more SMA materials, such as SMA ribbons or SMA wires as described herein, attached to the bimorph arm 9401 using techniques such as those described herein.

[0073] 95 shows an embodiment of a base including a bimorph arm with an offset, according to one embodiment. The bimorph arm 9501 includes a bimorph beam 9502 with a formed offset 9504. The bimorph arm can also include a limiter, using techniques such as those described herein. The bimorph arm 9501 includes one or more SMA materials, such as SMA ribbons or SMA wires 9506 as described herein, attached to the bimorph arm 9501, using techniques such as those described herein.

[0074] FIG. 96 illustrates an embodiment of a base 9608 including two bimorph arms with offsets, according to one embodiment. Each bimorph arm 9601a, 9601b includes a bimorph beam 9602a, 9602b with a formed offset 9604a, 9604b. Each bimorph arm 9601a, 9601b includes one or more SMA materials, such as SMA ribbons or SMA wires 9606a, 9606b, as described herein, attached to the bimorph arm 9501 using techniques such as those described herein. Each bimorph arm 9601a, 9601b can also include a limiter, using techniques such as those described herein. Some embodiments include a base including two or more bimorph arms formed using techniques such as those described herein. According to some embodiments, the bimorph arm 9601 is integrally formed with the base 9608. In other embodiments, one or more of the bimorph arms 9602a, 9602b are formed separately from the base 9608 and attached to the base 9608 using techniques including, but not limited to, soldering, resistance welding, laser welding, and adhesives. In some embodiments, two or more bimorph arms 9601a, 9601b are configured to act on a single object. This can increase the force applied to the object. The following graph in FIG. 107 shows an example of how box volume, an approximation of a box that encompasses the entire bimorph actuator, is related to the work per bimorph component. The box volume is approximated using the length of the bimorph actuator 9612, the width of the bimorph actuator 9610, and the height of the bimorph actuator 9614 (collectively referred to as the "box volume").

[0075] FIG. 97 illustrates a buckler arm including a load point extension, according to one embodiment. The buckler arm 9701 includes a beam portion 9702 and one or more load point extensions 9704a, 9704b extending from the beam portion 9702. Each end 9706a, 9706b of the buckler arm 9701 is configured to be attached to or integrally formed with a plate or other base using techniques such as those described herein. The one or more load point extensions 9704a, 9704b are attached to or integrally formed with the beam portion 9702, offset from the load points 9710a, 9710b of the beam portion 9702, according to some embodiments. The load points 9710a, 9710b are portions of the beam portion 9702 configured to transfer the force of the buckler arm 9701 to another object. In some embodiments, the load points 9710a, 9710b are in the center of the beam portion 9702. In other embodiments, the load points 9710a, 9710b are at a location other than the center of the beam portion 9702. The load point extensions 9704a, 9704b are configured to extend in the direction of the longitudinal axis of the beam portion 9702 from the point where they are joined to the beam portion 9702 toward the load points 9710a, 9710b of the beam portion 9702. In some embodiments, the ends of the load point extensions 9704a, 9704b extend at least to the load points 9710a, 9710b of the beam portion 9702. The buckler arm 9701 includes one or more SMA materials, such as SMA ribbons or SMA wires 9712, as described herein. The SMA materials, such as the SMA wires 9712, are attached at both ends of the beam portion 9702. The SMA materials are attached to both ends of the beam portion using techniques such as those described herein. In some embodiments, the length of the load point extensions 9704a, 9704b can be configured to any length that is included within the longitudinal length of the associated flat (non-actuated) beam portion 9702 of the buckler arm 9701.

[0076] 98 shows a buckler arm 9801 including a load point extension 9810 according to one embodiment in an actuated position. SMA material attached to both ends of beam section 9802 is actuated using techniques such as those described herein. The load point 9804 allows the buckler arm 9801 to have an increased stroke range over a buckler arm without the extension. Thus, a buckler arm including a load point extension allows for a greater maximum vertical stroke. Buckler arms with load point extensions can be included in SMA actuators and systems as described herein.

[0077] FIG. 99 illustrates a bimorph arm including a load point extension according to one embodiment. The bimorph arm 9901 includes a beam portion 9902 and one or more load point extensions 9904a, 9904b extending from the beam portion. One end of the bimorph arm 9901 is configured to be attached to or integrally formed with a plate or other base using techniques such as those described herein. The end of the beam portion 9902 opposite the attached or integrally formed end is not fixed and is free to move. The one or more load point extensions 9904a, 9904b are attached to or integrally formed with the beam portion 9902 offset from the free end of the beam portion 9902 according to some embodiments. The load point extensions 9904a, 9904b are configured to extend from a point where they are joined to the beam portion 9902 in a direction away from a plane that includes the longitudinal axis of the beam portion 9902. For example, one or more load point extensions 9904a, 9904b extend in a direction that the free ends of the beam portions extend when actuated. Some embodiments of the bimorph arm 9901 include one or more load point extensions 9904a, 9904b having a longitudinal axis that forms an angle, such as between 1 degree and 90 degrees, with a plane that contains the longitudinal axes of the beam portions. In some embodiments, the ends 9910a, 9910b of the load point extensions 9904a, 9904b are configured to engage an object configured to be moved.

[0078] The bimorph arm 9901 includes one or more SMA materials, such as SMA ribbons or wires 9906, as described herein. The SMA materials, such as SMA wires 9906, are attached at both ends of the beam portion 9902. The SMA materials are attached to both ends of the beam portion 9902 using techniques such as those described herein. In some embodiments, the length of the load point extensions 9904a, 9904b can be configured to be any length. The location of the engagement point of an object by the ends 9910a, 9910b of the load point extensions 9904a, 9904b can be configured to be at any point along the longitudinal length of the beam portion 9902, according to some embodiments. The height of the ends of the load point extensions above the beam portion when the beam portion is flat (unactuated) can be configured to be any height. In some embodiments, the load point extensions can be configured to be above at least other portions of the bimorph arm when the bimorph arm is actuated.

[0079] FIG. 100 illustrates a bimorph arm including a load point extension according to one embodiment in an actuated position. SMA material attached to both ends of beam portion 2 is actuated using techniques such as those described herein. The load point extension 10 allows the bimorph arm 1 to increase stroke force over a bimorph arm without an extension. Thus, the bimorph arm 1 including the load point extension 10 allows a greater force to be applied by the bimorph arm 1. The bimorph arm 1 with the load point extension 10 can be included in SMA actuators and systems as described herein.

[0080] FIG. 101 illustrates an SMA optical image stabilization mechanism according to one embodiment. SMA optical image stabilization mechanism 20 includes a moving plate 22 and a stationary plate 24. Moving plate 22 includes a spring arm 26 formed integrally therewith. In some embodiments, moving plate 22 and stationary plate 24 are each formed to be a single, one-piece plate. Moving plate 22 includes a first SMA material mounting portion 28a and a second SMA material mounting portion 28b. Stationary plate 24 includes a first SMA material mounting portion 30a and a second SMA material mounting portion 30b. Each SMA material mounting portion 28, 30 is configured to secure an SMA material, such as an SMA wire, to the plate using a resistance weld joint. The first SMA material attachment portion 28a of the movable plate 22 includes a first SMA wire 32a disposed between the first SMA material attachment portion 30a of the stationary plate and a second SMA wire 32b disposed between the second SMA material attachment portion 30b of the stationary plate 24. The second SMA material attachment portion 28b of the movable plate 22 includes a third SMA wire 32c disposed between the second SMA material attachment portion 30b of the stationary plate and a fourth SMA wire 32d disposed between the first SMA material attachment portion 30a of the stationary plate 24. Actuating each SMA wire using techniques such as those described herein moves the movable plate 22 away from the stationary plate 24. FIG. 102 illustrates an SMA material attachment portion 40 of the movable portion according to one embodiment. The SMA material attachment portion is configured to have an SMA material such as an SMA wire 41 resistance welded to the SMA material attachment portion 40. FIG. 103 shows the SMA mounting portion 42 of the stationary plate with resistance welded SMA wire 43 attached, according to one embodiment.

[0081] FIG. 104 illustrates an SMA actuator 45 including a buckle actuator, according to one embodiment. Buckle actuator 46 includes buckle arms 47 as described herein. Buckle arms 47 are configured to move in the z-axis when SMA wires 48 are actuated and deactuated using techniques such as those described herein. Each SMA wire 48 is attached to a respective resistance weld wire crimp 49 using resistance welding. Each resistance weld wire crimp 49 includes an isolated island 50 from the metal 51 that forms the buckle arm 47 on at least one side of the SMA wire 48. The island structure can be used in other actuators, optical image stabilization, and autofocus systems to connect at least one side of the SMA wire to an isolated island structure formed in a base metal layer, such as the OIS application shown in FIG.

[0082] FIG. 105 shows a resistance weld crimp including islands for an SMA actuator according to one embodiment, used to attach an SMA wire 48 to a buckle actuator 46 using techniques such as those described herein. FIG. 105a shows a bottom portion of an SMA actuator 45. The SMA actuator 45 is formed from a stainless steel base layer 51 according to some embodiments. A dielectric layer 52, such as a polyimide layer, is disposed on the bottom of the stainless steel base layer 51. A conductor layer 53, according to some embodiments, is electrically connected to the stainless steel island 50 through vias in the dielectric layer 52, allowing electrical connections to be made between wires welded to the stainless steel island 50 and conductor circuits attached to the stainless steel island. The island 50 is etched from the stainless steel base layer according to some embodiments. The dielectric layer 52 maintains the position of the island 50 within the stainless steel base layer 51. The island 50 is configured to attach an SMA wire using techniques such as those described herein, such as resistance welding. FIG. 105b shows a top portion of an SMA actuator 45 including the island 50. In some embodiments, a glue or adhesive may be placed over the welds to aid in mechanical strength and act as a fatigue strain relief during operation and shock loading.

[0083] 108 includes a lens system including an SMA actuator with a buckle actuator, according to one embodiment. The lens system includes a liquid lens assembly 61 disposed on a base 62. The lens system also includes a molding ring / coupler 64 that is mechanically coupled with the buckle actuator 60. An SMA actuator including a buckle actuator 60 as described herein is disposed on a sliding base 65 that is disposed on the base 62. The SMA actuator is configured to move the molding ring / coupler 64 along the optical axis of the liquid lens assembly 61 by actuating the buckle actuator 60 using techniques such as those described herein. This moves the molding ring / coupler 64, changing the focus of the liquid lens in the liquid lens assembly.

[0084] 109 illustrates a free load point end of a bimorph arm according to one embodiment. The free load point end 70 of the bimorph arm includes a flat surface 71 for attachment of an SMA material such as an SMA wire 72. The SMA wire 72 is attached to the flat surface 71 by a resistance weld 73. The resistance weld 73 is formed using techniques such as those known in the art.

[0085] FIG. 110 illustrates a free load point end of a bimorph arm according to one embodiment. The free load point end 76 of the bimorph arm includes a flat surface 77 for attaching an SMA material such as an SMA wire 78. The SMA wire 78 is attached to the flat surface 77 by resistance welding, similar to that shown in FIG. 109. An adhesive 79 is placed on the resistance weld. This allows for a more reliable bond between the SMA wire 78 and the free load point end 76. The adhesive 79 includes, but is not limited to, conductive adhesives, non-conductive adhesives, and other adhesives known in the art.

[0086] FIG. 111 illustrates a bimorph arm free load point end according to one embodiment. The bimorph arm free load point end 80 includes a flat surface 81 for attaching an SMA material such as an SMA wire 82. A metal interlayer 84 is disposed on the flat surface 81. The metal interlayer 84 includes, but is not limited to, a gold layer, a nickel layer, or an alloy layer. The SMA wire 82 is attached to the metal interlayer 84 disposed on the flat surface 81 by a resistance weld 83. The resistance weld 83 is formed using techniques such as those known in the art. The metal interlayer 84 allows for better adhesion to the free load point end 80.

[0087] FIG. 112 illustrates a bimorph arm free load point end according to one embodiment. The bimorph arm free load point end 88 includes a flat surface 89 for attaching an SMA material such as an SMA wire 90. A metal interlayer 92 is disposed on the flat surface 89. The metal interlayer 92 includes, but is not limited to, a gold layer, a nickel layer, or an alloy layer. The SMA wire 90 is attached to the flat surface 89 by resistance welding, similar to that shown in FIG. 111. An adhesive 91 is disposed on the resistance weld. This allows for a more reliable bond between the SMA wire 90 and the free load point end 88. The adhesive 91 includes, but is not limited to, conductive adhesives, non-conductive adhesives, and other adhesives known in the art.

[0088] 113 illustrates a fixed end of a bimorph arm according to one embodiment. The fixed end 95 of the bimorph arm includes a flat surface 96 for attaching an SMA material, such as an SMA wire 97. The SMA wire 97 is attached to the flat surface 96 by a resistance weld 98. The resistance weld 98 is formed using techniques such as those known in the art.

[0089] FIG. 114 illustrates a fixed end of a bimorph arm according to one embodiment. The fixed end 120 of the bimorph arm includes a flat surface 121 for attaching an SMA material, such as an SMA wire 122. The SMA wire 122 is attached to the flat surface 121 by resistance welding, similar to that illustrated in FIG. 113. An adhesive 123 is placed on the resistance weld. This allows for a more reliable bond between the SMA wire 122 and the fixed end 120. The adhesive 123 includes, but is not limited to, conductive adhesives, non-conductive adhesives, and other adhesives known in the art.

[0090] FIG. 115 illustrates a fixed end of a bimorph arm according to one embodiment. The fixed end 126 of the bimorph arm includes a flat surface 127 for attaching an SMA material, such as an SMA wire 128. A metal interlayer 130 is disposed on the flat surface 127. The metal interlayer 130 includes, but is not limited to, a gold layer, a nickel layer, or an alloy layer. The SMA wire 128 is attached to the metal interlayer 130 disposed on the flat surface 127 by a resistance weld 129. The resistance weld 129 is formed using techniques such as those known in the art. The metal interlayer 130 allows for better adhesion with the fixed end 126.

[0091] FIG. 116 illustrates a fixed end of a bimorph arm according to one embodiment. The fixed end 135 of the bimorph arm includes a flat surface 136 for attaching an SMA material, such as an SMA wire 137. A metal interlayer 138 is disposed on the flat surface 136. The metal interlayer 136 includes, but is not limited to, a gold layer, a nickel layer, or an alloy layer. The SMA wire 137 is attached to the flat surface 136 by resistance welding, similar to that illustrated in FIG. 115. An adhesive 139 is disposed on the resistance weld. This allows for a more reliable bond between the SMA wire 137 and the fixed end 135. The adhesive 139 includes, but is not limited to, conductive adhesives, non-conductive adhesives, and other adhesives known in the art.

[0092] FIG. 117 shows a rear view of a fixed end of a bimorph arm according to one embodiment. The bimorph arm 143 is constructed according to embodiments described herein. The fixed end 143 of the bimorph arm includes an island 144 that is isolated from an outer portion 145 of the fixed end 143. This allows the island 144 to be electrically insulated and / or thermally isolated from the outer portion 145. In some embodiments, the SMA material attached to the opposite side of the fixed end 143 of the bimorph arm is electrically coupled to the SMA material, such as an SMA wire, through a via. The island 144 is disposed on an insulator 146 as described herein. The island 144 may be formed using an etching technique, such as techniques known in the art.

[0093] 118 illustrates a loose load point end 70 of a bimorph arm according to one embodiment. The loose load point end 70 of the bimorph arm includes a planar surface 71 configured to include a radiating surface region 74 extending from a resistance weld region 73. The radiating surface region 74 includes a distal portion 76 and a proximal portion 75. The planar surface 71 is configured to have an SMA material, such as an SMA wire 72, attached to the planar surface 71. According to some embodiments, the SMA wire 72 is attached to the planar surface 71 at the resistance weld region 73 by resistance welding. The resistance weld is formed using techniques such as those known in the art. In other embodiments, the SMA wire 72 is attached to the planar surface 71 using other attachment techniques such as those described herein.

[0094] The temperature reduction of the unanchored load point end 70 is relative to the phase transition temperature of the SMA wire 72. The radiating surface area 74 significantly increases the surface area of ​​the unanchored load point end 70.

[0095] The increased surface area improves temperature reduction at the unanchored load point end 70. The increased surface area allows for cooling to prevent phase transformation of the shape memory alloy during operation. 119 illustrates a free load point end 170 of a bimorph arm according to one embodiment. The free load point end 170 of the bimorph arm includes a planar surface 171 configured to include a radiating surface region 174 extending from a resistance weld region 173.

[0096] Radiating surface region 174 includes distal portion 176 and proximal portion 175. Planar surface 171 is configured with an SMA material, such as an SMA wire 172, attached to planar surface 171. According to some embodiments, SMA wire 172 is attached to planar surface 171 by resistance welding to resistance weld region 173. In other embodiments, SMA wire 172 is attached to planar surface 171 using other attachment techniques, such as those described herein.

[0097] The unsecured load point end 170 also includes a proximal opening 178 and a distal opening 179 separated by a resistance weld region 173. The proximal opening 178 and the distal opening 179 are formed using techniques such as those known in the art. Although the openings 178 and 179 are shown as fully through features, in some examples the openings 178 and 179 may be partially etched.

[0098] Proximal opening 178 and distal opening 179 physically interrupt plane 171 and define the location of resistance weld region 173. Openings 178 and 179 are configured to mitigate interference between wire 172 and plane 171 near resistance weld region 173, according to some embodiments.

[0099] 120 illustrates a bimorph arm free load point end 270 according to one embodiment. The bimorph arm free load point end 270 includes a planar surface 271 configured to include a radiating surface region 274 extending from a resistance weld region 273. The planar surface 271 is configured to have an SMA material, such as an SMA wire 272, attached to the planar surface 271. According to some embodiments, the SMA wire 272 is attached to the planar surface 271 by resistance welding to the resistance weld region 273. In other embodiments, the SMA wire 272 is attached to the planar surface 271 using other attachment techniques, such as the techniques described herein.

[0100] The free load point end 270 also includes a proximal opening 278 and a distal opening 279 separated by a resistance weld region 273. The free load point end 270 also includes an elongated opening 280 that corresponds to a portion of the SMA wire 272. The elongated opening 280 may be removed to create clearance for the SMA wire 272 in the wire. In some embodiments, the elongated opening 280 extends from the proximal opening 278. Although the openings 278, 279, and 280 are shown as fully through features, the openings 278, 279, and 280 may be partially etched in some examples.

[0101] Proximal opening 278 and distal opening 279 physically interrupt plane 271 and define the location of resistance weld region 273. Similarly, elongated opening 280 physically interrupts plane 271 and defines the location of SMA wire 272. Apertures 278, 279, and 280 are configured to mitigate interference between wire 272 and plane 271 near resistance weld region 273, according to some embodiments.

[0102] FIG. 121 illustrates a free load point end 370 of a bimorph arm according to one embodiment. Planar surface 371 is configured with an SMA material, such as an SMA wire 372, attached to planar surface 371. According to some embodiments, SMA wire 372 is attached to planar surface 371 at least in part by resistance welding to a resistance weld area 373 isolated by nonlinear aperture 378. In some configurations, nonlinear aperture 378 is U-shaped to physically isolate up to 90% of resistance weld area 373. Resistance weld area 373 can be attached on a weld tongue defined by nonlinear aperture 378. In other embodiments, SMA wire 372 is attached to planar surface 371 using other attachment techniques, such as those described herein. Although nonlinear aperture 378 is shown as a fully through feature, in some examples nonlinear aperture 378 may be partially etched.

[0103] The increased surface area from the radiating surface region 374 allows for cooling to prevent phase transition of the shape memory alloy during actuation. In some alternative embodiments, the resistance weld region 373 may be completely etched away from the free load point end 370. Alternatively, the resistance weld region 373 may include a partially etched slot to increase tongue conformance.

[0104] 122 illustrates a free load point end 470 of a bimorph arm according to one embodiment. An adjacent planar surface 471 is provided for attachment of an SMA material such as an SMA wire 472. The SMA wire 472 is attached to the planar surface 471 by a resistance weld region 473, which is at least partially isolated by a nonlinear aperture 478.

[0105] Resistance weld area 473 may be attached using a partially etched slot 479 in non-linear aperture 478. In some configurations, non-linear aperture 478 physically interrupts plane 471 and defines the location of resistance weld area 473. Apertures 178 and 179 are configured to mitigate interference between wire 172 and plane 171 near resistance weld area 173, according to some embodiments. Although apertures 178 and 179 are shown as fully through features, in some examples apertures 178 and 179 may be partially etched.

[0106] The increased surface area from the emitting surface region 474 allows for cooling to prevent phase transformation of the shape memory alloy during operation. The disclosed embodiments can be applied to the fixed end of a bimorph arm, and Figures 123-125 are provided herein as exemplary embodiments of fixed ends incorporating the disclosed embodiments.

[0107] 123 illustrates a fixed end of a bimorph arm according to one embodiment. The fixed end 95 of the bimorph arm includes a flat surface 96 for attachment of an SMA material, such as an SMA wire 97. The SMA wire 97 is attached to the flat surface 96 by a resistance weld region 98. The resistance weld region 98 is formed using techniques such as those known in the art.

[0108] Fixed end 95 includes a proximal opening 93 and a distal opening 94 separated by a resistance weld region 98. Proximal opening 93 and distal opening 94 are formed using techniques such as those known in the art.

[0109] Proximal opening 93 and distal opening 94 physically interrupt plane 96 and define the location of resistance weld 98. Apertures 93 and 94 are configured, according to some embodiments, to mitigate interference between SMA wire 97 and plane 96 near resistance weld area 98. Although apertures 93 and 94 are shown as fully through features, in some examples apertures 93 and 94 may be partially etched.

[0110] 124 illustrates a fixed end of a bimorph arm according to one embodiment. Fixed end 195 of the bimorph arm includes a flat surface 196 for attaching an SMA material, such as an SMA wire 197. SMA wire 197 is attached to flat surface 196 by resistance welding at resistance weld region 198. Resistance weld region 198 is formed using techniques such as those known in the art.

[0111] Fixed end 195 includes a proximal opening 193 and a distal opening 194 separated by a resistance weld region 198. Proximal opening 193 and distal opening 194 are formed using techniques such as those known in the art.

[0112] Fixed end 195 also includes an elongated opening 160 that corresponds to a portion of SMA wire 197. Elongated opening 160 may be removed to provide clearance for SMA wire 197. In some embodiments, elongated opening 160 extends from distal opening 194.

[0113] Proximal opening 193 and distal opening 194 at least partially physically isolate resistance weld region 198. Elongated opening 160 physically interrupts plane 196 and defines the location of SMA wire 197. Apertures 194 and 196 are configured, according to some embodiments, to mitigate interference between SMA wire 197 and plane 196 near resistance weld region 198. Although apertures 194 and 196 are shown as fully through features, in some examples apertures 194 and 196 may be partially etched.

[0114] 125 illustrates a fixed end 295 of a bimorph arm according to one embodiment. The fixed end 295 of the bimorph arm includes a flat surface 296 for attaching an SMA material, such as an SMA wire 297. The SMA wire 297 is attached to the flat surface 296 by resistance welding at a resistance weld region 298.

[0115] The resistance weld area 298 is at least partially isolated by the nonlinear aperture 294. In some configurations, the nonlinear aperture 294 is U-shaped to physically isolate up to 90% of the resistance weld area 298. The resistance weld 298 can be attached on a weld tongue defined by the nonlinear aperture 294.

[0116] The non-linear aperture 294 physically interrupts the plane 296 and defines the location of the resistance weld region 298. The linear aperture 294 is configured, according to some embodiments, to mitigate interference between the SMA wire 297 and the plane 296 near the resistance weld region 298. In some alternative embodiments, the resistance weld region 298 may be etched completely from the fixed end 295. Alternatively, the resistance weld region 298 may include a partial etch slot to reduce the contact area.

[0117] FIG. 126 illustrates a balanced bimorph actuator according to one embodiment. The balanced bimorph actuator included two bimorph arms formed and configured using techniques such as those described herein. The balanced bimorph actuator includes two bimorph arms arranged in opposite directions, and is therefore configured to counterbalance its own friction component. The friction force component of each bimorph arm acts in a different direction than the desired force stroke of each bimorph arm. According to some embodiments, the balanced bimorph actuator includes at least a first bimorph arm and at least another bimorph arm configured to have a friction force component acting in an opposite direction to the first bimorph arm. Thus, the balanced bimorph actuator is configured to counterbalance the sliding friction caused by one or more bimorph arms. This allows for more precise control with less or no need to actively counteract undesired friction forces. Balanced bimorph actuators, including those described herein, overcome the problem of other bimorph actuators generating friction force components at the tip. These other bimorph actuators generate a pushing force in the Y direction, and also generate an unwanted force in the X direction by sliding in the X direction along the surface of the actuator's pushed member. This creates a small amount of unwanted motion in the X direction that the control system must compensate for. However, these compensating bimorph actuators also induce their own unwanted friction forces. This requires complex control algorithms to achieve good motion performance, for example to be used in optical image stabilization systems.

[0118] FIG. 127 shows an optical image stabilization including balanced bimorph actuators, according to one embodiment. The balanced bimorph actuators on all sides are positioned in opposite directions, so they act to cancel their own friction components. Since the net friction is near zero, open-loop position errors are minimal. Small errors are due in some instances to typical assembly and component size tolerances, and can be easily corrected by using a closed-loop control system.

[0119] FIG. 128 illustrates a balanced bimorph actuator according to an embodiment. The balanced bimorph actuator includes two bimorph arms as described herein, the two bimorph arms being arranged in a linear mirror symmetric orientation. According to some embodiments, the first bimorph arm is configured to have a friction force component primarily in the direction of the fixed end of the first bimorph arm parallel to the longitudinal axis of the balanced bimorph actuator. The second bimorph arm is configured in line with the first bimorph arm such that the fixed end of the second bimorph arm is adjacent to the fixed end of the first bimorph arm. The second bimorph arm is configured to have a friction force component in the opposite direction to the first bimorph arm. This results in approximately zero net total friction for the balanced bimorph actuator. In some embodiments, each bimorph arm of the balanced bimorph actuator includes an SMA wire. In some examples, the SMA wires are connected in series and configured to receive equal currents in both wires, for example, through a one-channel input for controlling the actuation of the actuator. In another example, the SMA wires are connected in parallel and configured to receive a current equal to the current of each of the power sources.

[0120] Figure 129 illustrates a balanced bimorph actuator according to an embodiment that includes a polyimide layer configured to retain and isolate the metal components. Figure 130 illustrates a balanced bimorph actuator according to an embodiment that includes a common base island. The common base island is the fixed end of the first and second bimorph arms.

[0121] FIG. 131 illustrates a balanced bimorph actuator according to one embodiment. The balanced bimorph actuator includes two bimorph arms arranged in an inverse linear orientation as described herein. According to some embodiments, the first bimorph arm is configured to have a friction force component primarily in the direction of the fixed end of the first bimorph arm parallel to the longitudinal axis of the balanced bimorph actuator. The second bimorph arm is configured in line with the first bimorph arm such that the fixed ends of the bimorph arm are at both ends of the bimorph actuator. Thus, the free ends of the first bimorph arm and the second bimorph are positioned in close proximity to each other. The second bimorph arm is configured to have a friction force component in the opposite direction to the first bimorph arm. This results in approximately zero net total friction for the balanced bimorph actuator. In some embodiments, each bimorph arm of the balanced bimorph actuator includes an SMA wire. In some embodiments, the SMA wires are connected in series and configured to receive equal currents in both wires, for example through a single channel input for controlling the actuation of the actuator, while in other embodiments, the SMA wires are connected in parallel and configured to receive currents equal to the currents of their respective power sources.

[0122] Figure 132 illustrates a balanced bimorph actuator according to an embodiment that includes a polyimide layer configured to retain and isolate metal components, and Figure 133 illustrates a balanced bimorph actuator according to an embodiment that includes a control input pad and a ground pad.

[0123] FIG. 134 illustrates a balanced bimorph actuator according to one embodiment. The balanced bimorph actuator includes two bimorph arms as described herein, the two bimorph arms being arranged in a linear mirror symmetric orientation. According to some embodiments, the first bimorph arm is configured to have a friction force component primarily in the direction of the fixed end of the first bimorph arm parallel to the longitudinal axis of the balanced bimorph actuator. The second bimorph arm is configured in line with the first bimorph arm such that the fixed end of the second bimorph arm is adjacent to the fixed end of the first bimorph arm. The second bimorph arm is configured to have a friction force component in the opposite direction to the first bimorph arm. This results in approximately zero net total friction for the balanced bimorph actuator. In some embodiments, a single SMA wire is used, with each end of the SMA wire being coupled to a respective unfixed end of each bimorph arm. The single SMA wire allows for more stroke for the balanced bimorph actuator.

[0124] Figure 135 illustrates a balanced bimorph actuator according to an embodiment including a single SMA wire, and Figure 136 illustrates a balanced bimorph actuator according to an embodiment including a single SMA wire, configured for a control input pad, and a ground pad.

[0125] FIG. 137 illustrates a balanced bimorph actuator according to one embodiment. The balanced bimorph actuator includes two bimorph arms as described herein arranged in a staggered orientation. According to some embodiments, the first bimorph arm is configured to have a friction force component in the direction of the fixed end of the first bimorph arm that is primarily parallel to the longitudinal axis of the first bimorph arm. The second bimorph arm is configured to be staggered with the first bimorph arm such that the longitudinal axis of the second bimorph arm is approximately parallel to the longitudinal axis of the first bimorph arm. Furthermore, the fixed ends of the bimorph arms are at both ends of the bimorph actuator. Thus, the unfixed end of the first bimorph arm and the second bimorph are offset with respect to each other. The second bimorph arm is configured to have a friction force component in the opposite direction to the first bimorph arm. This results in approximately zero net total friction for the balanced bimorph actuator. In some embodiments, each bimorph arm of the balanced bimorph actuator includes an SMA wire. In some examples, the SMA wires are connected in series and configured to receive equal currents in both wires, for example through a single channel input for controlling actuation of the actuator. In other examples, the SMA wires are connected in parallel and configured to receive currents equal to the currents of their respective power sources.

[0126] Figure 138 shows a balanced bimorph actuator with alternating orientations according to one embodiment including a polyimide layer configured to hold and isolate the metal components, and Figure 139 shows a balanced bimorph actuator according to one embodiment including a control input pad and a ground pad.

[0127] FIG. 140 illustrates an optical image stabilization including balanced bimorph actuators, according to one embodiment. The balanced bimorph actuators on all sides are positioned in opposite directions, so they act to cancel their own friction components. Since the net friction is near zero, open-loop position errors are minimal. Small errors are due in some instances to typical assembly and component size tolerances, and can be easily corrected by using a closed-loop control system.

[0128] FIG. 141 shows an exploded view of an optical image stabilization including a balanced bimorph actuator, according to one embodiment. The optical image stabilization is configured to receive a bimorph actuator as described herein, which self-positions flush into a pocket on the outer housing. This configuration allows for a smaller X / Y footprint for the bimorph module, by allowing the bimorph actuator, such as the balanced bimorph actuator described herein, to share the same X / Y space as the outer housing. This also simplifies assembly of the bimorph module by allowing the bimorph actuator to be inserted in a final step from the outside. The outer housing can be made of molded plastic, metal, or other materials.

[0129] FIG. 142 shows an optical image stabilization including a balanced bimorph actuator, according to one embodiment. The optical image stabilization is configured to receive a bimorph actuator as described herein, which self-positions flush into a pocket on the outer housing. This configuration allows for a smaller X / Y footprint for the bimorph module, by allowing the bimorph actuator, such as the balanced bimorph actuator described herein, to share the same X / Y space as the outer housing. This also simplifies assembly of the bimorph module by allowing the bimorph actuator to be inserted in a final step from the outside. The outer housing can be made of molded plastic, metal, or other materials.

[0130] FIG. 143 illustrates a sensor-shifting optical image stabilization including a bimorph actuator, according to one embodiment. The optical image stabilization is configured to receive a balanced bimorph actuator as described herein configured as a balanced carriage. The bimorph carriage is configured to insert from the outside of the sensor-shifting OIS module. In some embodiments, the sensor-shifting OIS also induces a rotation of the image sensor, which can be controlled to suppress roll excitation as well as X / Y excitation, using an off-center bimorph actuator design. This configuration allows for a smaller X / Y footprint for the bimorph module, by having the bimorph actuator, such as the balanced bimorph actuator described herein, share the same X / Y space as the outer housing. This also simplifies assembly of the bimorph module by allowing the bimorph actuator to be inserted in a final step from the outside. The outer housing can be made of molded plastic, metal, or other materials.

[0131] FIG. 144 shows an optical image stabilization including a balanced bimorph actuator, according to one embodiment. The optical image stabilization is configured to receive a bimorph actuator as described herein, which self-positions flush into a pocket on the outer housing. This configuration allows for a smaller X / Y footprint for the bimorph module, by allowing the bimorph actuator, such as the balanced bimorph actuator described herein, to share the same X / Y space as the outer housing. This also simplifies assembly of the bimorph module by allowing the bimorph actuator to be inserted in a final step from the outside. The outer housing can be made of molded plastic, metal, or other materials.

[0132] Fig. 145 shows a metal outer housing fabricated as molded metal that is attached with molded plastic in an insert molding process, and Fig. 146 shows a metal outer can embodiment that includes pockets formed into four sides of the outer can that are configured to allow for flush mounting of a bimorph actuator as described herein.

[0133] FIG. 147 illustrates an optical image stabilization 147 including a bimorph actuator, according to one embodiment. The optical image stabilization 147 includes an actuator 1470, and a side view of a bimorph 1471 disposed around the actuator 1470 is shown. Each bimorph 1471 may be configured with a bearing element 1472 disposed between the bimorph 1471 and an outer contact surface 1473 of the actuator 1470, according to one embodiment. The four bimorphs 1471 may be formed and configured using techniques such as those described herein. It is understood that the optical image stabilization 147 may include more or less than the four bimorphs shown herein. The actuator 1471 includes a bearing element 1472 configured to minimize or reduce friction between the bimorph 1471 and the outer contact surface 1473 of the actuator 1470. In some examples, a lubricating material may be used to further reduce friction of the bearing element 1472. For example, a suitable lubricant, such as, but not limited to, cleanroom grease, may be employed as a means for providing lubrication to the bearing elements 1472. Additionally, a suitable lubricant may be used as a means to help hold the bearing elements in place.

[0134] Bimorph actuators on all sides act to minimize their own frictional components by incorporating bearing elements. Since the net friction is near zero, open loop position errors are minimal. Small errors are due in some instances to typical assembly and component size tolerances and can be easily corrected by using a closed loop control system.

[0135] The incorporation of bearing elements 1472 allows for more precise control with less or no need to actively counteract undesired frictional forces. The actuator 1470 including the bimorph 1471 described herein overcomes the problem of other bimorph actuators that generate a frictional force component at the tip. These other bimorph actuators generate a pushing force in the Y direction and also generate an undesired force in the X direction by sliding in the X direction along the surface of the actuator's pushed member. This creates a small amount of undesired motion in the X direction that the control system must compensate for. However, these compensating bimorph actuators also induce their own undesired frictional forces. This requires complex control algorithms to achieve good motion performance, for example as used in optical image stabilization system 147.

[0136] FIG. 148A is an isometric view of a bimorph actuator 1480 having a sphere 1486 formed thereon. The sphere 1486 is configured to reduce or minimize friction and may be referred to herein as a friction reducing sphere or bearing. The bimorph actuator 1480 may include a base island 1485, a non-fixed load point end 1487, and a metal beam 1481 connecting the non-fixed load point end 1487 to the base island 1485. The sphere 1486 may be formed on the non-fixed load point end 1487. FIG. 148B is a detailed view of the non-fixed load point end 1487 and the sphere 1486 formed thereon. FIG. 149 is a top and side view of the bimorph actuator 1480 of FIG. 148A, according to one embodiment. The bimorph actuator 1480 includes a control input pad 1483 and a ground pad 1484.

[0137] The design of the friction reducing sphere 1486 can, for example, control the vector of normal forces acting on the moving parts while minimizing the surface contact area between the moving parts. The sphere 1486 is configured to reduce friction and can facilitate the desired motion by minimizing friction between the bimorph actuator 1480 and the outer contact surface of the actuator (of FIG. 147).

[0138] This substantially minimizes friction in the bimorph actuator. In some embodiments, each metal beam 1481 of the bimorph actuator 1480 includes an SMA wire 1482. In some examples, the SMA wires 1482 are connected in series and configured to receive equal currents in both wires, for example through a one channel input for controlling actuation of the bimorph actuator 1480. In other examples, the SMA wires 1482 are connected in parallel and configured to receive currents equal to the currents of their respective power sources.

[0139] FIG. 150 shows top and side views of a bimorph actuator 1500 having a ball bearing 1501 housed within a non-fixed load point end 1587, according to one embodiment. The non-fixed load point end 1587 includes a bearing configured to reduce or minimize friction, which may be configured as a cantilever element 1502 at the non-fixed load point end 1587. The cantilever element 1502 may include a semicircular receiving space that houses at least one freely rotating metal ball (ball bearing 1501). The ball bearing 1501 includes at least one rolling element, such as a ball having a circular cross section. The ball may be fixed within the non-fixed load point end 1587 of the bimorph actuator 1500 by the cantilever element 1502.

[0140] The design of the ball bearings 1501 may, for example, control the vector of normal forces on the moving parts while minimizing the surface contact area between the moving parts. The ball bearings 1501 may facilitate the desired motion by minimizing friction between the bimorph actuator 1500 and the outer contact surface of the actuator (of FIG. 147). In some examples, a lubricating material may be implemented to further reduce friction in the ball bearings 1501. For example, clean room grease may be implemented as a lubricating means for the ball bearings 1501. Additionally, a suitable lubricant may be used to help hold the ball bearings in place.

[0141] In some embodiments, each metal beam 1581 of the bimorph actuator 1500 includes an SMA wire 1582. In some examples, the SMA wires 1582 are connected in series and configured to receive equal currents in both wires, for example through a one-channel input for controlling actuation of the bimorph actuator 1500. In other examples, the SMA wires 1582 are connected in parallel and configured to receive currents equal to the currents of their respective power sources.

[0142] FIG. 151 shows top and side views of a bimorph actuator 1510 having a ball bearing 1511 housed within a non-fixed load point end 1587, according to one embodiment. The non-fixed load point end 1587 includes a bearing 1512 configured to reduce friction, which may be attached to the non-fixed load point end 1587. The friction reducing bearing 1512 may be fixed to the non-fixed load point end 1587 at welds 1512A and 1512B. In other examples, the friction reducing bearing 1512 may be fixed to the non-fixed load point end 1587 using other disclosed techniques. The friction reducing bearing 1512 includes a semicircular receiving space that houses at least one freely rotating metal ball (ball bearing 1511). The ball bearing 1511 includes at least one rolling element, such as a ball having a circular cross section. The ball may be fixed within the free load point end 1587 of the bimorph actuator 1510 by a friction reducing bearing 1512 .

[0143] The design of the ball bearings 1511 can, for example, control the vector of normal forces on the moving parts while minimizing the surface contact area between the moving parts. The ball bearings 1511 may facilitate the desired motion by minimizing friction between the bimorph actuator 1510 and the outer contact surface of the actuator (FIG. 147). In some examples, a lubricating material may be implemented to further reduce friction in the ball bearings 1511. For example, clean room grease may be implemented as a lubricating means for the ball bearings 1511. Additionally, a suitable lubricant may be used to help hold the ball bearings in place.

[0144] FIG. 152 illustrates top and side views of a bimorph actuator 1520 having a spherical bearing 1521 housed within a non-fixed load point end 1587, according to one embodiment. The spherical bearing 1521 includes a shaft 1521B that rotates between an opening formed from the non-fixed load point end 1587. The opening in the non-fixed load point end 1587 is formed between the non-fixed load point end 1587 and a bearing 1522 configured to reduce friction, which may be attached to the non-fixed load point end 1587. The friction reducing bearing 1522 may be secured to the non-fixed load point end 1587 at welds 1522A and 1522B. In other examples, the friction reducing bearing 1522 may be secured to the non-fixed load point end 1587 using other disclosed techniques.

[0145] The bearing 1522 includes a semicircular receiving space that accommodates at least a portion of the shaft 1521B that rotates the spherical bearing 1521. The spherical bearing 1521 includes at least one rolling element, such as a roller 1521A having a circular cross section. The shaft 1521B may be configured to rotate while being fixed to the free load point end 1587 of the bimorph actuator 1520 by the friction reducing bearing 1522.

[0146] The design of the spherical bearing 1521 can, for example, control the vector of normal forces on the moving parts while minimizing the surface contact area between the moving parts. The spherical bearing 1521 may facilitate the desired motion by minimizing friction between the bimorph actuator 1510 and the outer contact surface of the actuator (in FIG. 147). In some examples, a lubricating material may be implemented to further reduce friction in the spherical bearing 1521. For example, clean room grease may be implemented as a lubricating means for the spherical bearing 1521. Additionally, a suitable lubricant may be used to help hold the spherical bearing in place.

[0147] FIG. 153 shows top and side views of a bimorph actuator 1530 having a spherical bearing 1531 housed within a non-fixed load point end 1587, according to one embodiment. The spherical bearing 1531 includes at least one rolling element, such as a roller 1531A having a circular cross section. The spherical bearing 1531 also includes a shaft 1531B that rolls between an opening in the non-fixed load point end 1587. The opening in the non-fixed load point end 1587 is formed between an arrangement of a first cantilever element 1532A and a second cantilever element 1532B in the non-fixed load point end 1587. It is understood that multiple cantilever elements may be implemented herein. The first cantilever element 1532A may include a semicircular element arranged in a first direction. Meanwhile, the second cantilever element 1532B may include a semicircular element arranged in a second direction opposite the first direction. In this manner, the arrangement of the first cantilever element 1532A and the second cantilever element 1532B may create a penetration configured to receive a portion of the shaft 1531B of the spherical bearing 1531.

[0148] The design of the spherical bearing 1531 can, for example, control the vector of normal forces on the moving parts while minimizing the surface contact area between the moving parts. The spherical bearing 1531 may facilitate the desired motion by minimizing friction between the bimorph actuator 1530 and the outer contact surface of the actuator (in FIG. 147).

[0149] FIG. 154A is a top and side view of a spherical bearing 1541 at its non-fixed load point end 1587 in an open state, according to one embodiment. FIG. 154B is a top and side view of a spherical bearing at its non-fixed load point end 1587 in a closed state, according to one embodiment. The non-fixed load point end 1587 includes a first configurable cantilever element 1542A and a second configurable cantilever element 1542B extending from the non-fixed load point end 1587. This is referred to as the open state and is shown in FIG. 154A. The distal ends of both the first configurable cantilever element 1542A and the second configurable cantilever element 1542B may be configured to fold back a portion of the length of each respective cantilever element forming an opening in the non-fixed load point end 1587. This is referred to as the closed state and is shown in FIG.

[0150] The spherical bearing 1541 also includes a shaft 1541B that rotates between an opening in the closed, non-fixed load point end 1587. The opening in the non-fixed load point end 1587 is formed between the arrangement of the first configurable cantilever element 1542A and the second configurable cantilever element 1542B of the non-fixed load point end 1587. In this manner, the arrangement of the first configurable cantilever element 1542A and the second configurable cantilever element 1542B can create a penetration configured to receive a portion of the shaft 1541B of the spherical bearing 1541.

[0151] It will be understood that terms such as "top," "bottom," "upper," "lower," and x-, y-, and z-directions used herein are used as terms of convenience to indicate the spatial relationship of parts relative to one another, rather than any particular spatial or gravitational orientation. These terms are therefore intended to encompass an assembly of component parts, whether the assembly is oriented in the particular orientation shown in the drawings and described herein, or oriented upside down from that orientation, or any other rotational variation.

[0152] It will be understood that the term "the present invention" as used herein should not be interpreted to mean that only a single invention having a single essential element or group of elements is presented. Similarly, it will be understood that the term "the present invention" encompasses several separate innovations, each of which can be considered as a separate invention. Although the present invention has been described in detail with reference to preferred embodiments and drawings thereof, it should be apparent to those skilled in the art that various adaptations and modifications of the embodiments of the present invention can be achieved without departing from the spirit and scope of the present invention. In addition, the techniques described herein can be used to create devices having 2, 3, 4, 5, 6, or more generally n bimorph and buckle actuators. It will therefore be understood that the above detailed description and accompanying drawings are not intended to limit the scope of the present invention, which should be inferred only from the following claims and their properly interpreted legal equivalents.

Claims

1. An actuator, a plurality of bimorph arms configured to reduce a net frictional force of the plurality of bimorph arms; a plurality of bearing elements, each of which is disposed between a bimorph arm and an outer contact surface of the actuator; An actuator comprising:

2. 2. The actuator of claim 1, wherein a bearing element of the plurality of bearing elements is configured to reduce friction and comprises a sphere formed on a free load point end of the bimorph arm.

3. The actuator of claim 1 , wherein a bearing element of the plurality of bearing elements comprises a ball bearing received in a free load point end of the bimorph arm.

4. The actuator of claim 3 , wherein the free load point end of the bimorph arm comprises a cantilever element having a semicircular receiving space for receiving the ball bearing.

5. a bearing configured to reduce friction and attached to the free load point end of the bimorph arm; The actuator of claim 3 , wherein the bearing includes a semicircular receiving space that receives the ball bearing.

6. The actuator of claim 1 , wherein a bearing element of the plurality of bearing elements comprises a spherical bearing received at a free load point end of the bimorph arm.

7. 7. The actuator of claim 6, wherein the spherical bearing includes at least one rolling element and a shaft that rolls between two openings formed from the non-fixed load point end.

8. 8. The actuator of claim 7, wherein the opening in the non-fixed load point end is formed between the non-fixed load point end and at least one bearing configured to reduce friction and attached to the non-fixed load point end.

9. 7. The actuator of claim 6, wherein the free load point end of the bimorph arm comprises a plurality of cantilever elements having a semicircular receiving space, and an arrangement of first and second cantilever elements forms a penetration configured to receive a portion of the spherical bearing.

10. the unanchored load point end comprises a first configurable cantilever element and a second configurable cantilever element extending from the unanchored load point end; 7. The actuator of claim 6, wherein a distal end of both the first configurable cantilever element and the second configurable cantilever element are configured to be folded over a portion of a length of each cantilever element forming an opening at the free load point end for receiving a portion of the spherical bearing.

11. The actuator of claim 1 , wherein each of the plurality of bimorph arms comprises a beam and one or more smart metal alloy (SMA) materials.

12. 12. The actuator of claim 11, wherein the SMA material comprises an SMA wire or an SMA ribbon.

13. The actuator of claim 1 , wherein each of the plurality of bimorph arms includes a metal beam and an SMA wire.

14. 1. An actuator module assembly comprising: an outer housing formed of plastic or metal configured to receive one or more bimorph actuators at an outer periphery of the outer housing, the bimorph actuators being configured to reduce frictional forces of the plurality of bimorph actuator arms; a plurality of bearing elements, each of which is disposed between a bimorph actuator arm of the plurality of bimorph actuator arms and an outer contact surface of an inner housing; An actuator module assembly comprising:

15. 15. The actuator module assembly of claim 14, wherein a bearing element of the plurality of bearing elements is configured to reduce friction and comprises a sphere formed on a free load point end of the bimorph actuator arm.

16. 15. The actuator module assembly of claim 14, wherein a bearing element of the plurality of bearing elements comprises a ball bearing received in a free load point end of the bimorph actuator arm.

17. 17. The actuator module assembly of claim 16, wherein the free load point end of the bimorph actuator arm comprises a cantilever element having a semicircular receiving space for receiving the ball bearing.

18. a bearing configured to reduce friction and attached to the free load point end of the bimorph actuator arm; The actuator module assembly of claim 16 , wherein the bearing includes a semicircular receiving space that receives the ball bearing.

19. 15. The actuator module assembly of claim 14, wherein a bearing element of the plurality of bearing elements comprises a spherical bearing received in a free load point end of the bimorph actuator arm.

20. 20. The actuator module assembly of claim 19, wherein the spherical bearing includes at least one rolling element and a shaft that rolls between two openings formed from the non-fixed load point end.

21. 21. The actuator module assembly of claim 20, wherein the opening in the non-fixed load point end is formed between the non-fixed load point end and at least one bearing configured to reduce friction and attached to the non-fixed load point end.

22. 20. The actuator module assembly of claim 19, wherein the free load point end of the bimorph actuator arm comprises a plurality of cantilever elements having a semicircular receiving space, and an arrangement of first and second cantilever elements forms a penetration configured to receive a portion of the spherical bearing.

23. the unanchored load point end comprises a first configurable cantilever element and a second configurable cantilever element extending from the unanchored load point end; 20. The actuator module assembly of claim 19, wherein a distal end of both the first configurable cantilever element and the second configurable cantilever element are configured to be folded over a portion of the length of each cantilever element forming an opening at the free load point end for receiving a portion of the spherical bearing.

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