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. Another embodiment of the actuator includes a base and at least one bimorph actuator comprising 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. More particularly, embodiments of the present invention relate 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 mechanism. These systems can be enclosed by a structure such as a shielding can. The movable assembly is supported for movement on a support assembly by bearings such as a plurality of 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 fixed support assembly and acts as a spring to allow movement of the movable assembly relative to the fixed 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 them. Each of the SMA wires has one end attached to the support assembly and an opposite end attached to the movable assembly. An electrical drive signal is applied to the SMA wires to actuate the suspension. However, these types of systems suffer from system complexity resulting in a bulky system requiring a large footprint and large height clearance. Additionally, current systems are unable to provide a high Z stroke range in a small, 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 be 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] FIG. 2 illustrates a lens assembly including an SMA actuator configured as a buckle actuator, according to one embodiment. [Figure 1b] FIG. 2 illustrates an SMA actuator according to one embodiment. [Diagram 2] FIG. 2 illustrates an SMA actuator according to one embodiment. [Diagram 3] FIG. 1 is an exploded view of an autofocus assembly including an SMA wire actuator according to one embodiment. [Figure 4] FIG. 1 illustrates an autofocus assembly including an SMA actuator according to one embodiment. [Diagram 5] FIG. 2 illustrates an SMA actuator including a sensor according to one embodiment. [Figure 6] 1A and 1B are top and side views of an SMA actuator configured as a buckle actuator according to one embodiment with a lens carriage attached. [Figure 7] FIG. 2 is a side view of a section of an SMA actuator according to one embodiment. [Figure 8] 1A-1D are multiple views of one embodiment of a buckle actuator. [Figure 9] FIG. 1 illustrates a bimorph actuator with a lens carriage according to one embodiment. [Figure 10] FIG. 1 is a cutaway view of an autofocus assembly including an SMA actuator according to one embodiment. [Figure 11a] FIG. 1 illustrates a bimorph actuator according to some embodiments. [Figure 11b] FIG. 1 illustrates a bimorph actuator according to some embodiments. [Figure 11c] FIG. 1 illustrates a bimorph actuator according to some embodiments. [Figure 12] FIG. 2 illustrates an embodiment of a bimorph actuator, in accordance with one embodiment. [Figure 13] FIG. 13 illustrates a cross section of an end pad of a bimorph actuator according to one embodiment. [Figure 14] FIG. 2 illustrates a cross section of a central power pad of a bimorph actuator in accordance with one embodiment. [Figure 15] FIG. 1 is an exploded view of an SMA actuator including two buckle actuators according to one embodiment. [Figure 16] FIG. 1 illustrates an SMA actuator including two buckle actuators according to one embodiment. [Figure 17] FIG. 13 is a side view of an SMA actuator including two buckle actuators according to one embodiment. [Figure 18] FIG. 13 is a side view of an SMA actuator including two buckle actuators according to one embodiment. [Figure 19] FIG. 1 is an exploded view of an assembly including an SMA actuator that includes two buckle actuators according to one embodiment. [Figure 20] FIG. 1 illustrates an SMA actuator including two buckle actuators according to one embodiment. [Figure 21] FIG. 1 illustrates an SMA actuator including two buckle actuators according to one embodiment. [Figure 22]FIG. 1 illustrates an SMA actuator including two buckle actuators according to one embodiment. [Diagram 23] FIG. 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] FIG. 24 illustrates an SMA system including an SMA actuator including a buckle actuator 2402 with a laminate hammock, according to one embodiment. [Figure 26] FIG. 1 illustrates a buckle actuator including a laminate hammock according to one embodiment. [Figure 27] FIG. 1 illustrates a laminate hammock of an SMA actuator according to one embodiment. [Figure 28] FIG. 13 illustrates a laminate molded crimp connection of an SMA actuator according to one embodiment. [Figure 29] FIG. 1 illustrates an SMA actuator including a buckle actuator with a laminate hammock. [Diagram 30] FIG. 1 is an exploded view of an SMA system including an SMA actuator, including a buckle actuator, according to one embodiment. [Diagram 31] FIG. 1 illustrates an SMA system including an SMA actuator, including a buckle actuator, according to one embodiment. [Diagram 32] FIG. 1 illustrates an SMA actuator including a buckle actuator according to one embodiment. [Diagram 33] FIG. 13 illustrates a two-yoke capture joint of a pair of buckle arms of an SMA actuator according to one embodiment. [Diagram 34] FIG. 13 illustrates a resistance weld crimp for an SMA actuator according to one embodiment, used to attach the SMA wire to a buckle actuator. [Diagram 35]FIG. 13 illustrates an SMA actuator including a buckle actuator with a two-yoke capture joint. [Diagram 36] FIG. 2 illustrates an SMA bimorph liquid lens according to one embodiment. [Figure 37] FIG. 2 shows an SMA bimorph liquid lens viewed obliquely from above according to one embodiment. [Figure 38] 1A and 1B are cross-sectional and bottom views of an SMA bimorph liquid lens according to one embodiment. [Figure 39] FIG. 1 illustrates an SMA system including an SMA actuator with a bimorph actuator according to one embodiment. [Diagram 40] FIG. 1 illustrates an SMA actuator with a bimorph actuator according to one embodiment. [Diagram 41] FIG. 13 shows the length of the bimorph actuator and the location of the bond pads where the SMA wire extends the wire length beyond the bimorph actuator. [Diagram 42] FIG. 2 is an exploded view of an SMA system including a bimorph actuator according to one embodiment. [Diagram 43] FIG. 2 is an exploded view of a subsection of an SMA actuator according to one embodiment. [Diagram 44] FIG. 1 illustrates a subsection of an SMA actuator according to one embodiment. [Diagram 45] FIG. 1 illustrates a five-axis sensor shifting system according to one embodiment. [Diagram 46] FIG. 1 illustrates an exploded view of a five-axis sensor shifting system in accordance with one embodiment. [Figure 47] FIG. 13 illustrates an SMA actuator including a bimorph actuator incorporated in the circuit for all movements, according to one embodiment. [Figure 48] FIG. 1 illustrates an SMA actuator according to one embodiment, including a bimorph actuator incorporated in the circuit for all movements. [Figure 49] FIG. 1 illustrates a cross-section of a five-axis sensor shifting system in accordance with one embodiment. [Figure 50] FIG. 1 illustrates an SMA actuator according to an embodiment including a bimorph actuator. [Figure 51] 1A-1C are top views of an SMA actuator according to one embodiment, including a bimorph actuator that moves an image sensor at different x and y positions. [Figure 52] FIG. 1 illustrates an SMA actuator including a bimorph actuator according to one embodiment configured as a box bimorph autofocus. [Figure 53] FIG. 1 illustrates an SMA actuator including a bimorph actuator according to one embodiment. [Figure 54] FIG. 1 illustrates an SMA actuator including a bimorph actuator according to one embodiment. [Figure 55] FIG. 1 illustrates an SMA actuator including a bimorph actuator according to one embodiment. [Figure 56] FIG. 1 illustrates an SMA system including an SMA actuator according to one embodiment including a bimorph actuator. [Figure 57] FIG. 1 is 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 is a cross-sectional view 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] FIG. 1 illustrates a box bimorph actuator according to one embodiment. [Figure 60] FIG. 1 illustrates an SMA system including an SMA actuator according to one embodiment including a bimorph actuator. [Figure 61] FIG. 1 is an exploded view of an SMA system including an SMA actuator according to one embodiment including a bimorph actuator. [Figure 62]FIG. 1 illustrates a cross-section of an SMA system including an SMA actuator according to one embodiment including a bimorph actuator. [Figure 63] FIG. 1 illustrates a box bimorph actuator according to one embodiment. [Figure 64] FIG. 1 illustrates an SMA system including an SMA actuator according to one embodiment including a bimorph actuator. [Figure 65] FIG. 1 is an exploded view of an SMA system including an SMA actuator according to one embodiment including a bimorph actuator. [Figure 66] FIG. 1 illustrates an SMA system including an SMA actuator according to one embodiment including a bimorph actuator. [Figure 67] FIG. 1 illustrates an SMA system including an SMA actuator according to one embodiment including a bimorph actuator. [Figure 68] FIG. 1 illustrates an SMA system including an SMA actuator according to one embodiment including a bimorph actuator. [Figure 69] FIG. 1 is an exploded view of an SMA including SMA actuator according to one embodiment including a bimorph actuator. [Figure 70] FIG. 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] FIG. 1 illustrates a box bimorph actuator component according to one embodiment. [Figure 72] FIG. 1 illustrates a flexible sensor circuit for use in an SMA system according to one embodiment. [Figure 73] FIG. 1 illustrates an SMA system including an SMA actuator according to one embodiment including a bimorph actuator. [Figure 74] FIG. 1 is an exploded view of an SMA system including an SMA actuator according to one embodiment including a bimorph actuator. [Figure 75]FIG. 1 illustrates a cross-section of an SMA system including an SMA actuator according to one embodiment. [Figure 76] FIG. 1 illustrates a box bimorph actuator according to one embodiment. [Figure 77] FIG. 1 illustrates a flexible sensor circuit for use in an SMA system according to one embodiment. [Figure 78] FIG. 1 illustrates an SMA system including an SMA actuator according to one embodiment including a bimorph actuator. [Figure 79] FIG. 1 is an exploded view of an SMA system including an SMA actuator according to one embodiment including a bimorph actuator. [Figure 80] FIG. 1 illustrates a cross-section of an SMA system including an SMA actuator according to one embodiment. [Figure 81] FIG. 1 illustrates a box bimorph actuator according to one embodiment. [Figure 82] FIG. 1 illustrates a flexible sensor circuit for use in an SMA system according to one embodiment. [Figure 83] FIG. 1 illustrates an SMA system including an SMA actuator according to one embodiment including a bimorph actuator. [Figure 84] FIG. 1 is an exploded view of an SMA system including an SMA actuator according to one embodiment. [Figure 85] FIG. 1 illustrates a cross-section of an SMA system including an SMA actuator according to one embodiment including a bimorph actuator. [Figure 86] FIG. 1 illustrates a box bimorph actuator for use in an SMA system according to one embodiment. [Figure 87] FIG. 1 illustrates a flexible sensor circuit for use in an SMA system according to one embodiment. [Figure 88] FIG. 13 illustrates exemplary dimensions for a bimorph actuator of an SMA actuator according to one embodiment. [Figure 89]FIG. 2 illustrates a lens system for a folded camera according to one embodiment. [Figure 90] 1A-1D illustrate several embodiments of a lens system including a liquid lens according to one embodiment. [Figure 91] FIG. 13 illustrates a folding lens, which is a prism, positioned above the actuator, according to one embodiment. [Figure 92] FIG. 13 illustrates a bimorph arm including an offset according to one embodiment. [Figure 93] FIG. 1 illustrates a bimorph arm including an offset and a limiter according to one embodiment. [Figure 94] FIG. 1 illustrates a bimorph arm including an offset and a limiter according to one embodiment. [Figure 95] FIG. 13 illustrates an embodiment of a base with a bimorph arm including an offset according to one embodiment. [Figure 96] FIG. 13 illustrates an embodiment of a base with two bimorph arms including an offset according to one embodiment. [Figure 97] FIG. 13 illustrates a buckler arm including a load point extension according to one embodiment. [Figure 98] A diagram showing a buckler arm 9801 including a load point extension 9810 according to one embodiment. [Figure 99] FIG. 1 illustrates a bimorph arm including a load point extension according to one embodiment. [Figure 100] FIG. 1 illustrates a bimorph arm including a load point extension according to one embodiment. [Figure 101] FIG. 2 illustrates an SMA optical image stabilization mechanism according to one embodiment. [Figure 102] FIG. 4 shows an SMA material attachment portion 40 of the movable part according to one embodiment. [Figure 103] FIG. 13 illustrates a SAM mounting portion of a stationary plate with resistance welded SMA wires attached according to one embodiment. [Figure 104]FIG. 4 illustrates an SMA actuator 45 that includes a buckle actuator according to one embodiment. [Figure 105a] FIG. 13 illustrates a resistance weld crimp including islands for an SMA actuator according to one embodiment. [Figure 105b] FIG. 13 illustrates a resistance weld crimp including islands for an SMA actuator according to one embodiment. [Fig. 106] FIG. 13 illustrates the relationship between bending surface z offset, valley width, and peak force of a bimorph beam according to one embodiment. [Figure 107] FIG. 13 illustrates an example of how box volume, an approximation of a box enclosing the entire bimorph actuator, relates to work per bimorph component according to one embodiment. [Figure 108] FIG. 1 illustrates a liquid lens actuated using a buckler actuator according to one embodiment. [Figure 109] FIG. 13 illustrates an unanchored load point end of a bimorph arm according to one embodiment. [Figure 110] FIG. 13 illustrates an unanchored load point end of a bimorph arm according to one embodiment. [Figure 111] FIG. 13 illustrates an unanchored load point end of a bimorph arm according to one embodiment. [Figure 112] FIG. 13 illustrates an unanchored load point end of a bimorph arm according to one embodiment. [Figure 113] FIG. 13 illustrates a fixed end of a bimorph arm according to one embodiment. [Fig. 114] FIG. 13 illustrates a fixed end of a bimorph arm according to one embodiment. [Figure 115] FIG. 13 illustrates a fixed end of a bimorph arm according to one embodiment. [Fig. 116] FIG. 13 illustrates a fixed end of a bimorph arm according to one embodiment. [Figure 117] FIG. 13 illustrates a rear view of a fixed end of a bimorph arm according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0006] Described herein are embodiments of SMA actuators that include a small 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 used in mobile phones or wearable devices configured to provide a user with an alert, notification, warning, touch area, or push button response. Additionally, two or more SMA actuators can be used to achieve a larger stroke in a system.

[0007] In various embodiments, the SMA actuator has a z-stroke greater than 0.4 millimeters. Additionally, the SMA actuator for various embodiments has a height in the z-direction of 2.2 millimeters or less when in its initial, parked position. Various embodiments of an SMA actuator configured as an autofocus actuator in a lens assembly can have a footprint as small as 3 millimeters greater than the lens inner diameter ("ID"). According to various embodiments, the SMA actuator can have a footprint that is wider in one direction than another 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 than another, for example, the length of the SMA actuator is 0.5 millimeters greater than the 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, this causes buckle actuator 102 to latch and at least a central portion 104 of each buckle actuator 102 to move in a z-stroke direction, e.g., in the positive z-direction, as shown by arrow 108. According to some embodiments, SMA wire 100 is actuated when an electric current is supplied to one end of the wire passing through a wire holder, such as crimp structure 106. The electric current flows through SMA wire 100 and heats it due to the inherent resistance in the SMA material from which SMA wire 100 is made. The other side of the SMA wire 100 has a wire holder, such as a crimp structure 106, that connects the SMA wire 100 to complete the circuit to ground. Heating the SMA wire 100 to a sufficient temperature changes the unique material properties from a martensite crystal structure to an austenite crystal structure, thereby changing the length of the wire. 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 provide 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 when 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 including those known in the art, a return spring 308, a vertical slide bearing 310, and a guide cover 312. The lens carriage 306 is configured such that the SMA wire is actuated and pulled using techniques including those described herein to slide against the vertical slide bearing 310 when the SMA actuator 302 moves in a z-stroke direction, e.g., the positive z direction, when the buckle actuator 302 is buckled. The return spring 308 is configured to exert a force on the lens carriage 306 in a direction opposite to the z-stroke direction, using techniques including those known in the art. The return spring 308 is configured, according to various embodiments, to move the lens carriage 306 in the opposite direction of the z-stroke direction when the tension in the SMA wire decreases as the SMA wire comes to rest. When the tension in the SMA wire decreases to an initial value, the lens carriage 306 moves to a minimum height in the z-stroke direction. Figure 4 illustrates an autofocus assembly including an SMA actuator according to one 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 movement of the SMA actuator in the z-direction or the movement of a component that the SMA actuator is moving using techniques including those known in the art. The SMA actuator includes one or more buckle actuators 506 configured for actuation 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 of movement that the lens carriage 306 moves in the z-direction 504 from an initial position using techniques including those known in the art. According to some embodiments, the sensor is a tunneling magnetoresistance ("TMR") sensor.

[0012] FIG. 6 illustrates 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 illustrates a side view of a section of the SMA actuator 602 according to the embodiment illustrated in FIG. 6. According to the embodiment illustrated in FIG. 7, the SMA actuator 602 includes a slide base 702. According to one embodiment, the slide base 702 is formed from a metal, such as stainless steel, using techniques including those known in the art. However, one of ordinary skill in the art will appreciate that other materials may be used to form the slide base 702. Additionally, the slide base 702 according to some embodiments has a spring arm 612 coupled to the SMA actuator 602. According to various embodiments, the spring arm 612 is configured to provide 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 downwards, e.g., in the negative z direction, after the SMA wire 602 has moved the SMA actuator 602 in the z-stroke direction, i.e., in the positive z direction. Thus, when actuated, the SMA wire 608 is configured to contract and move the SMA actuator 602 in the z-stroke direction, and when deactivated, to move the SMA actuator 602 in the opposite direction to the z-stroke direction.

[0013] The SMA actuator 602 also includes a buckle actuator 710. In various embodiments, the buckle actuator 710 is formed from a metal, such as stainless steel. The buckle actuator 710 further 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 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 that are 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 can 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 the buckle arms 610 of the buckle actuator 710 are configured to move when the SMA wire 608 is actuated, thereby pulling the pair of wire retainers 606 toward each other. According to various embodiments, the SMA wire 608 is electrically actuated to move and control the position of the buckle arms 610 when a current is applied to the SMA wire 608. The SMA wire 608 stops when the current is removed or below a threshold. This causes the pair of wire retainers 606 to move apart, and the buckle arms 610 to move in a direction opposite to the direction in which the SMA wire 608 was actuated. According to various embodiments, the buckle arms 610 are configured to have an initial angle of 5 degrees with respect to the slide base 702 when the SMA wire is resting in its initial position. Also, at full stroke, or when the SMA wire is fully actuated, the buckle arm 610 is configured to have an angle of 10-12 degrees relative to the sliding base 702 according to various embodiments.

[0014] According to the embodiment shown in Figures 6 and 7, the SMA actuator 602 also includes a slide bearing 706 configured between the slide base 702 and the wire retainer 606. The slide bearing 706 is configured to minimize any friction between the slide base 702 and the buckle arms 610 and / or wire retainer 606. The slide bearing in some embodiments is attached to the slide bearing 706. According to various embodiments, the slide bearing is formed from 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 can 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 one embodiment of a buckle actuator 802 relative to the x, y, and z axes. As oriented in 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 together via a central portion, such as a hammock portion 806. The hammock portion 806, according to various embodiments, is configured to carry an object that the buckle actuator acts upon, for example, a portion of a lens carriage that the buckle actuator moves using techniques including those described herein. The hammock portion 806, according to some embodiments, is configured to provide lateral stiffness to the buckle actuator during actuation. In other embodiments, the buckle actuator does not include a hammock portion 806. According to these embodiments, the buckle arms are configured to act on an object to move the object. For example, the buckle arms are configured to act directly on a feature of the lens carriage to push it up.

[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 illustrated 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 can 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 curl up in the z-direction when actuated, 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 can be configured to help push the bimorph actuators down to their initial, rest position, as described herein. The small footprint of bimorph actuators allows the creation of SMA actuators with reduced footprints compared to current actuator technologies.

[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, such as those 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 including 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 ribbon 1106b (e.g., as shown in a perspective view of a bimorph actuator including an SMA ribbon according to an embodiment of FIG. 11b) or SMA wire 1106a (e.g., as shown in a 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 including 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 including those known in the art. The contacts 1110 according to various embodiments (e.g., as shown in Figures 11a and 11b) are gold-copper pads. According to embodiments, a bimorph actuator 1102 having a length of approximately 1 millimeter is configured to generate a large stroke, e.g., a pressing force of 50 milliNewtons ("mN"), as shown in Figure 11c, is used as part of a lens assembly. According to some embodiments, the use of a bimorph actuator 1102 having a lens larger than 1 millimeter generates a larger stroke but a smaller force than a bimorph actuator 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 can 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 shown in FIG. 12 includes a central feed 1204 that applies power. Power is supplied to the center of the SMA material 1202 (wire or ribbon), such as those described herein. The ends of the SMA material 1202 are grounded to a beam 1206 or base metal as a return at end pads 1203. The end pads 1203 are electrically isolated from the remainder of the contact layer 1214. According to an embodiment, 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 stopped. 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 to ensure a higher total current can be delivered to the wire. Without a uniform heat sink, portions of the wire, such as the center region, can become overheated and damaged, and therefore require reduced current and reduced motion to operate reliably. The center feed 1204 provides the benefits of faster wire activation / actuation (faster heating) and reduced power consumption of the SMA material 1202 for faster response time (reduced resistive path length). This allows for faster actuator motion and the ability to operate at higher translation frequencies.

[0021] 12, the beam 1206 includes a central metal 1208 that is insulated from the remainder of the beam 1206 to form a central feed 1204. An insulator 1210, such as those described herein, is disposed on top of the beam 1206. The insulator 1210 is configured to have 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 contacts to the central metal 1208 to form the central feed 1204. The contact layer 1214, such as those described herein, includes a power section 1214a and a ground section 1214b according to some embodiments that provide actuation / control signals to the bimorph actuator via a power contact 1216 and a ground contact 1218. A covercoat layer 1220, such as that described herein, is disposed over the contact layer 1214 to electrically isolate the contact layer except for portions of the contact layer 1214 to which electrical coupling is desired (e.g., one or more contacts).

[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. The gap is formed using etching techniques, including those known in the art, according to some embodiments. The end pad 1203 includes a via section 1224 configured to electrically couple the end pad 1203 to 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 the central metal 1208 by a via section 1226 of the central feed 1204 formed in a via 1212 formed in the insulator 1210.

[0024] The actuators described herein can be used to form actuator assemblies using multiple buckle actuators and / or bimorph actuators. According to one embodiment, the actuators can 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 according to embodiments described herein are positioned relative to one another to use their motions to act against one another. 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 according to various embodiments is configured to carry an object that one or more of the buckle actuators 1302, 1304 act on, such as a portion of a lens carriage 1306 that the buckle actuators move using techniques including those described above.

[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 effect movement of an object such as a lens carriage in the positive z-direction, or upward direction.

[0028] FIG. 18 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 effect movement of an object such as a lens carriage in the negative z-direction, 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. According to various embodiments, the hammock portion 1908 of each SMA actuator 1902, 1904 is configured to carry an object that one or more buckle actuators 1902, 1904 act on, for example, a portion of a lens carriage 1906 that the buckle actuators move using techniques including those described herein. In some embodiments, the SMA actuator includes a base portion 1918 configured to receive the second buckle actuator 1904. The SMA actuator can 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. This allows for better control of 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, which allows for pitch and roll rotation of the lens carriage for tilt OIS movement.

[0031] An embodiment of an SMA actuator that includes two buckle actuators eliminates the need to have a return spring. The use of two buckle actuators can improve / reduce hysteresis when using SMA wire resistance for position feedback. Opposing force SMA actuators that include two buckle actuators have less hysteresis than those that include return springs, which lends itself to more precise position control. In some embodiments, such as the embodiment shown in FIG. 22, an SMA actuator that includes two buckle actuators 2202, 2204 provides two-axis tilt using differential power to the left SMA wire 2218a and the right SMA wire 2218b of each buckle actuator 2202, 2204. For example, the left SMA wire 2218a is actuated with higher power than the right SMA wire 2218b. This causes the left side of the lens carriage 2206 to move downward and the right side to move (tilt) upward. The SMA wires of the first buckle actuator 2202, in some embodiments, are held at equal power to act as a fulcrum that pushes differentially against the SMA wires 2218a, 2218b to provide tilting motion. For example, applying equal power to the SMA wires of the second buckle actuator 2202 and using differential power to the left SMA 2218a and right SMA 2218b of the second buckle actuator 2204, reversing the power signal applied to the SMA wires will cause the lens carriage 2206 to tilt in the other direction. This allows an object such as a lens carrier to be tilted in either axis of motion, or can be adjusted to eliminate any tilt between the lens and the sensor for better dynamic tilt, resulting in better image quality across all pixels.

[0032] 23 illustrates an SMA actuator including two buckle actuators and a coupler according to one embodiment. The SMA actuator includes two buckle actuators such as those described herein. A first buckle actuator 2302 is configured to couple with a second buckle actuator 2304 using a coupler such as a coupler ring 2305. The buckle actuators 2302, 2304 are positioned relative to one another 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 placed on a sliding 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 actuator, including the two buckle actuators. In some embodiments, an additional spring can be added to push against the two bucklers to help push the actuator assembly and payload back down 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 cause the SMA actuator to move in the positive z-direction with one buckle actuator and in the negative z-direction with one 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 coupled to additional buckle actuators and pairs of buckle actuators 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 with one or more camera lens elements as an autofocus drive mechanism. 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 is reduced as the SMA wire 2408 stops, according to various embodiments. The SMA system of some embodiments includes a housing 2409 configured to receive the return spring 2403 and act as a slide bearing to guide the lens carriage in the z-stroke direction. The housing 2409 is also configured to be disposed over the 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 from a laminate. The buckle actuator 2402 also includes an SMA wire attachment structure, such as a laminate molded 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 mate 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 laminate molded crimp connection 2412. According to the embodiment shown in FIG. 26, the buckle arms 2404 are coupled together through a central portion such as a laminate hammock 2406. The laminate hammock 2406 according to various embodiments is configured to carry an object that the buckle actuator acts on, for example, a portion of a lens carriage that the buckle actuator moves using techniques including those described herein.

[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 motion. For example, the laminate hammock 2406 is formed using a copper layer disposed on a first polyimide layer with a second polyimide layer disposed on the copper layer. In some embodiments, the laminate hammock 2406 is formed on the buckle arm 2404 using deposition and etching techniques including those 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 including 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 buckle arm 2404 remains in place relative to the lens carriage.

[0039] 28 illustrates a laminate molded crimp connection for an SMA actuator according to one embodiment. The laminate molded crimp connection 2412 is configured to attach the SMA wire 2408 to the buckle actuator and form an electrical circuit junction with the SMA wire 2408. In various embodiments, the laminate molded 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 over at least a portion of the stainless steel portion forming the crimp 2413. A conductive layer, such as copper, is then disposed over the polyimide layer, which is electrically coupled to one or more signal traces 2415 disposed over the buckle actuator. Deforming the crimp to contact the SMA wire therein also causes the SMA wire to electrically contact the conductive layer. Thus, the conductive layer coupled to the signal trace or traces is used to apply a power signal to the SMA wire using techniques including those described herein. In some embodiments, a second polyimide layer is formed over the conductive layer in areas where the conductive layer does not contact the SMA wire. In some embodiments, the laminate molded crimp connection 2412 is formed over the crimp 2413 using deposition and etching techniques including those known in the art. In other embodiments, the laminate molded crimp connection 2412 and one or more electrical traces are formed separately from the crimp 2413 and the buckle actuator and attached to the crimp 2412 and the buckle actuator using techniques including 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, causing the buckle arms and laminate hammock to move in the positive z direction. And the laminate hammock in contact with an object, such as a lens carriage, thereby moving the object in the positive z direction. When the power signal is reduced or removed, the SMA wire expands, causing the buckle arms and laminate hammock to move 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, in some embodiments, is configured to be used with one or more camera lens elements as an autofocus drive mechanism. As shown in FIG. 30, the SMA system, in various embodiments, includes a return spring 3003 configured to move the lens carriage 3005 in a direction opposite to the z-stroke direction when tension in the SMA wire 3008 is reduced as the SMA wire stops. The SMA system, in some embodiments, includes a stiffener 3000 disposed on the return spring 3003. The SMA system, in some embodiments, includes a two-part housing 3009 configured to receive the return spring 3003 and act as a slide bearing to guide the lens carriage in the z-stroke direction. The housing 3009 is also configured to be disposed over the buckle actuator 3002. The buckle actuator 3002 includes a two-part slide base 3001 similar to that described herein. The slide base 3001, according to some embodiments, is split to electrically isolate the two sides (e.g., one side is ground and the other side is power) as current flows through portions of the slide base 3001 to the wires.

[0043] The buckle actuator 3002 includes buckle arms 3004. Each pair of the buckle actuators 3002 is formed in 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 that electrically couples 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 mate the SMA system or buckle adapter 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 illustrates an SMA actuator that includes 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 above. An SMA wire 2408 is attached to a resistance weld wire crimp 3012. According to the embodiment illustrated in Figure 32, the buckle arm 3004 is configured to mate with an object, such as a lens carriage, without a center section using a two yoke capture joint.

[0046] FIG. 33 shows a two yoke capture junction of a pair of buckle arms of an SMA actuator according to one embodiment. FIG. 33 also shows plating pads used to attach an optional flex circuit to the sliding base. In some embodiments, the plating pads are formed using gold. FIG. 34 shows a resistance weld crimp for 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 on top of the welds to help with mechanical strength and act as a fatigue strain relief during operation and shock loading.

[0047] FIG. 35 shows an SMA actuator including 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 contact an object, such as a lens carriage, thereby moving the object 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 press a shaped ring 3510 located on top of 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), allowing the bimorph actuators to function as an autofocus. The differential force from the bimorph actuator 3508 can move the light beam in the X and Y directions, allowing the bimorph actuator to act as an optical image stabilization mechanism according to some embodiments. Both OIS and AF functions can be achieved simultaneously with appropriate control for 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 that 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 an SMA bimorph liquid lens viewed from an oblique top view 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 motion in both directions throughout the 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 positive z-stroke displacement. Two SMA wires attached to the bottom of the component allow negative z-stroke displacement. In some embodiments, each bimorph actuator is attached to an object, such as a lens carriage 3910, using tabs that 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 z-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, such as those described herein.

[0050] 41 shows the length 4102 of the bimorph actuator 4103 and the location of the bond pad 4104 where the SMA wire 4206 extends the wire length beyond the bimorph actuator. A longer wire is used than the bimorph actuator to increase the stroke and force. Thus, the extension length 4108 of the SMA wire 4206 beyond the bimorph actuator 4103 is used to set the stroke and force for 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. SMA systems according to various embodiments are configured to use separate metal materials and non-conductive adhesives to create one or more electrical circuits that independently power the SMA wires. Some embodiments do not affect the AF size and include four bimorph actuators such as those described herein. 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 subsection of an SMA actuator according to one embodiment. The subsection includes a base 4304 with 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 including 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 with a wire bond pad 4316 for connecting the SMA wire 4312 of the bimorph actuator 4306 using techniques including 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 from a metal, for example stainless steel. The 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 to actuate the bimorph actuator 4306 using techniques including 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.Additionally, molded wire bond pads are used for the signal junctions to electrically couple SMA wires for power signals.

[0052] FIG. 45 illustrates 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 axis translation and pitch / roll tilt. Optionally, the system is configured to use only 4 axes, including X / Y axis translation and pitch / roll tilt, 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 an image sensor. In some embodiments, a static lens stack is mounted on top of the top cover and inserted inside the ID (without touching the inside of the orange moving carriage).

[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 into the bimorph circuit components using techniques including 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 such as those 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 according to one embodiment, including a bimorph actuator integrated in the circuit for all motions. An embodiment of the SMA actuator may include 8-12 bimorph actuators 4606. However, other embodiments may include more or fewer bimorph actuators. FIG. 48 shows an SMA actuator 4802 according to one embodiment, including a bimorph actuator integrated in the circuit for all motions, 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 moving an image sensor, lens or other various payloads in different x positions and y axes.

[0056] FIG. 52 illustrates an SMA actuator including a bimorph actuator 5202 according to an embodiment configured as a box bimorph autofocus. Four top and bottom mounted SMA bimorph actuators, such as those described herein, are configured to move together to provide movement in the z-stroke direction for autofocus movement. FIG. 53 illustrates an SMA actuator including a bimorph actuator according to an embodiment, where two top mounted bimorph actuators 5302 are configured to push one or more lenses down. FIG. 54 illustrates an SMA actuator including a bimorph actuator according to an embodiment, where two bottom mounted bimorph actuators 5402 are configured to push one or more lenses up. FIG. 55 illustrates an SMA actuator including a bimorph actuator according to an embodiment showing four top and bottom mounted SMA bimorph actuators 5502, such as those described herein, being used to move one or more lenses to provide tilting movement.

[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 / Y axis. In some embodiments, the Z-axis motion comes from a separate AF, such as those described herein. The four bimorph actuators push the sides of the autofocus for OIS motion. 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 used in an SMA system configured as a two-axis lens shift OIS, as manufactured before being molded to fit the system. Such a system can be configured to have a high OIS stroke OIS (e.g., ±200 μm or more). Additionally, such embodiments are configured to have a wide range of motion and excellent OIS dynamic tilt using four slide bearings, such as POM slide bearings. These 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 / Y / Z axes. In some embodiments, the pitch and yaw axis motion is for dynamic tilt adjustment functionality. Eight bimorph actuators are used to provide motion for autofocus and OIS 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 used in an SMA system configured as a 5-axis lens shift OIS and autofocus as manufactured before being molded to fit the system. Such systems can be configured to have high OIS strokes (e.g., ±200 μm or more) and high autofocus strokes (e.g., 400 μm or more). Additionally, such embodiments can be tuned to eliminate any tilt, eliminating 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 extrusion box. In some embodiments, the bimorph actuator assembly is configured to wrap around an object such as a lens carriage. There is a flexible section for low X / Y / Z stiffness because the circuit assembly is moving with the lens carriage. The end pads of the circuit are static. The extrusion box can be configured for 4 or 8 bimorph actuators. Thus, the extrusion box can be configured as 4 bimorph actuators on the side for OIS that moves in the X and Y axes. The extrusion box can be configured as 4 bimorph actuators on the top and bottom for autofocus that moves in the z axis. The extrusion box can be configured as 8 bimorph actuators on the top, bottom and sides for OIS and autofocus that moves in the x, y and z axes and is capable of 3-axis tilt (pitch / ro / 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 outward extrusion 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 outward extrusion box partially molded to receive the lens carriage 6604. FIG. 67 shows an SMA system including an SMA actuator 6602 including a bimorph actuator 6604 according to one embodiment configured as an outward extrusion box as manufactured before 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 movement 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 the 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 a box bimorph actuator 6802 component according to an embodiment used in an SMA system configured as a three-axis lens-shifting OIS during manufacture before being molded to fit the system. FIG. 72 shows a flexible sensor circuit used 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 OIS (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 excellent OIS dynamic tilt using four slide bearings, such as POM slide bearings. These 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 an 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 functions. Eight bimorph actuators are used to provide motion for autofocus and OIS using the techniques described herein. FIG. 74 shows an exploded view of an SMA system including an SMA actuator 7402 according to an 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 an 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 an embodiment used in an SMA system configured as a 6-axis lens-shifting OIS and autofocus as manufactured before being molded to fit the system. FIG. 77 shows a flexible sensor circuit for use in an SMA system according to an 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). Furthermore, such an embodiment can be adjusted to eliminate any tilt, eliminating 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 OIS pitch and yaw movement 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 used in an SMA system configured as a 2-axis lens shift OIS, as manufactured before being molded to fit the system. FIG. 82 shows a flexible sensor circuit used in an SMA system configured as a 2-axis camera tilt OIS, according to an embodiment. Such systems can be configured to have high OIS stroke (e.g., ±3 degrees or greater). These 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 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 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 used in an SMA system according to an embodiment configured as a 3-axis camera tilt OIS, as manufactured before being molded to fit the system. FIG. 87 shows a flexible sensor circuit used in an SMA system according to an embodiment configured as a 3-axis camera tilt OIS. Such a system can be configured to have a high OIS stroke OIS (e.g., ±3 degrees or more). These embodiments are configured to easily integrate with AF designs (e.g., VCM or SMA).

[0064] 88 shows example dimensions of a bimorph actuator of an SMA actuator according to an embodiment. The dimensions are of a preferred embodiment, but one of ordinary skill in the art will appreciate that other dimensions can be used based on the desired characteristics for 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 angled with respect to a transmission axis 8906 that is parallel to the direction of travel of the light before it reaches the folded lens 8902. For example, a folded camera is used in a camera phone system 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, such as those described herein. The embodiment shown in FIG. 89 includes two liquid lenses 8903b, 8903d, such as those described herein. The one or more liquid lenses 8903b, 8903d are configured to be actuated using techniques including those described herein. The liquid lenses are actuated using actuators including, but not limited to, buckler actuators, bimorph actuators, and other SMA actuators. FIG. 108 illustrates a liquid lens actuated using a buckler actuator 60, according to one embodiment. The liquid lens includes a molded ring coupler 64, a liquid lens assembly 61, one or more buckler actuators 60, such as those described herein, a sliding base 65, and a base 62. The one or more buckler 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, alone or in combination with other lenses, can be configured to act as an autofocus or optical image stabilization mechanism. A liquid lens can also be configured to direct an image onto an image sensor in other ways.

[0067] 90 illustrates several embodiments of a lens system 9001 including liquid lenses 9002a-h that focus an image onto an image sensor 9004. As shown, the liquid lenses 9002a-h can be configured to include any lens shape and to be dynamically configured to adjust the light path through the lenses using techniques including 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, such as that shown in FIG. 91. In the example shown in FIG. 91, the folded lens is a prism 9102 disposed on an actuator 9104. The actuator includes an SMA actuator, including but not limited to those described herein. In some embodiments, the prism tilt is disposed on an SMA actuator, including four bimorph actuators 9106, such as those described herein. The actuated folded lens 9100 according to some embodiments is configured as an optical image stabilization mechanism using techniques including those described herein. For example, the actuated folded lens is configured to include an SMA system, such as that shown in FIG. 39. Another example of an actuated folded lens can include an SMA actuator, such as that shown in FIG. 21. However, the folded lens can include other actuators as well.

[0069] FIG. 92 illustrates a bimorph arm including 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 to generate higher forces 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 valley width 9206) are configured to define characteristics of the bimorph arm, such as the peak force. For example, the graph in FIG. 106 illustrates bending plane z offset 9204, valley width 9206, and peak force of bimorph beam 9202 according to one embodiment.

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

[0071] 93 illustrates a bimorph arm including 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 to generate higher forces than a bimorph arm 9301 without the 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 including the shaped offset 9303 and limiter 9304 can be included in SMA actuators and systems such as those described herein. The bimorph arm 9301 includes one or more SMA materials such as SMA ribbons or SMA wires 9308, such as those described herein, attached to the bimorph arm 9301 using techniques including those described herein.

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

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

[0074] FIG. 96 illustrates an embodiment of a base 9608 including two bimorph arms including offsets, according to one embodiment. Each bimorph arm 9601a, 9601b includes a bimorph beam 9602a, 9602b with a shaped offset 9604a, 9604b. Each bimorph arm 9601a, 9601b includes one or more SMA materials, such as SMA ribbons or SMA wires 9606a, 9606b, such as those described herein, attached to the bimorph arm 9501 using techniques including those described herein. Each bimorph arm 9601a, 9601b can also include a limiter using techniques including those described herein. Some embodiments include a base including three or more bimorph arms formed using techniques including 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, solder, 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 allow for increased force to be applied to the object. The following graph in FIG. 107 shows an example of how box volume, which is an approximation of a box that encloses the entire bimorph actuator, relates to the work per bimorph component. The box volume is approximated using the length of bimorph actuator 9612, the width of bimorph actuator 9610, and the height of bimorph actuator 9614 (collectively referred to as "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 including those described herein. The one or more load point extensions 9704a, 9704b according to some embodiments are attached to or integrally formed with the beam portion 9702 offset from the load points 9710a, 9710b of the beam portion 9702. The load points 9710a, 9710b are portions of the beam portion 9702 that are 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 from where they are joined to the beam portion 9702 toward the load points 9710a, 9710b of the beam portion 9702 in the direction of the longitudinal axis of the beam portion 9702. In some embodiments, the ends of the load point extensions 9704a, 9704b extend to at least 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, such as those described herein. The SMA materials, such as SMA wires 9712, are attached to both ends of the beam portion 9702. The SMA materials are attached to both ends of the beam portion using techniques including those described herein. In some embodiments, the length of the load point extensions 9704a, 9704b can be configured to any length that is contained 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 including those described herein. Load points 9804 allow the buckler arm 9801 to increase the stroke range up the buckler arm without stretching. Thus, a buckler arm including a load point extension allows for a larger maximum vertical stroke. Buckler arms including load point extensions can be included in SMA actuators and systems such as those 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 including 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 according to some embodiments are attached to or integrally formed with the beam portion 9902 offset from the free end of the beam portion 9902. The load point extensions 9904a, 9904b are configured to extend from 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, the one or more load point extensions 9904a, 9904b extend in a direction that the free ends of the beam portions extend in 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 with a plane that includes the longitudinal axis of the beam portion, the angle being in the range of 1 degree to 90 degrees. In some embodiments, the ends 9910a, 9910b of the load point extensions 9904a, 9904b are configured to engage an object configured to move.

[0078] The bimorph arm 9901 includes one or more SMA materials, such as SMA ribbons or wires 9906, such as those described herein. The SMA materials, such as SMA wires 9906, are attached to both ends of the beam portion 9902. The SMA materials are attached to both ends of the beam portion 9902 using techniques including 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 according to some embodiments can be configured to be anywhere along the longitudinal length of the beam portion 9902. 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 shows 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 including those described herein. The load point extension 10 allows the bimorph arm 1 to increase the stroke force on the bimorph arm without stretching. Thus, the bimorph arm 1 including the load point extension 10 allows for a greater force to be applied by the bimorph arm 1. The bimorph arm 1 including the load point extension 10 can be included in SMA actuators and systems such as those 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 integrally formed therewith. In some embodiments, moving plate 22 and stationary plate 24 are each formed to be a single, integral 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 SMA material, such as 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 it and the first SMA material attachment portion 30a of the stationary plate, and a second SMA wire 32b disposed between it and the second SMA 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 it and the second SMA material attachment portion 30b of the stationary plate, and a fourth SMA wire 32d disposed between it and the first SMA attachment portion 30a of the stationary plate 24. Actuating each SMA wire using techniques including 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 SMA material, such as SMA wire 41, resistance welded to the SMA material attachment portion 40. FIG. 103 shows the SMA mounting portion 42 of the stationary plate to which the resistance welded SMA wire 43 is 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 such as those described herein. Buckle arms 47 are configured to move in the z-axis when SMA wires 48 are actuated and deactuated using techniques including 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 island 50 isolated from the metal 51 forming the buckle arm 47 on at least one side of the SMA wire 48. The island structure can be used to connect at least one side of an SMA wire to an isolated island structure formed in a base metal layer in other actuators, optical image stabilization, and autofocus systems, 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 including those described herein. FIG. 105a shows the bottom of an SMA actuator 45. The SMA actuator 45 according to some embodiments is formed from a stainless steel base layer 51. 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 50 through vias in the dielectric layer 52, which allows for electrical connection between a wire welded to the stainless steel island 50 and a conductor circuit attached to the stainless steel island. The island 50 according to some embodiments is etched from the stainless steel base layer. 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 to the island 50 using techniques including those described herein, such as resistance welding. Figure 105b shows the top of the SMA actuator 45 including the island 50. In some embodiments, a glue or adhesive can also be placed on top of the weld to aid in mechanical strength and act as a fatigue strain relief during operation and shock loading.

[0083] FIG. 108 includes a lens system including an SMA actuator including 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 to the buckle actuator 60. An SMA actuator including a buckle actuator 60, such as those 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 including those described herein. This moves the molding ring / coupler 64 to change 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 SMA material, such as SMA wire 72. The SMA material 72 is attached to the flat surface 71 by a resistance weld 73. The resistance weld 73 is formed using techniques including 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 attachment of an SMA material, such as an SMA wire 78. The SMA wire 78 is attached to the flat surface 77 by a resistance weld similar to that shown in FIG. 109. An adhesive 79 is placed on top of 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 can include, but is not limited to, a conductive adhesive, a non-conductive adhesive, and other adhesives known in the art.

[0086] 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 attachment of an SMA material, such as an SMA wire 82. A metal interlayer 84 is disposed on the flat surface 81. The metal interlayer 84 may include, 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 may be formed using techniques including 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 attachment of an SMA material, such as an SMA wire 90. A metal interlayer 92 is disposed on the flat surface 89, including but 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 a resistance weld similar to that shown in FIG. 111. An adhesive 91 is disposed on the resistance weld, which 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 a conductive adhesive, a non-conductive adhesive, 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 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 98. The resistance weld 98 is formed using techniques including 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 a resistance weld similar to that shown in FIG. 113. An adhesive 123 is placed on top of the resistance weld. This allows for a more reliable bond between the SMA wire 122 and the fixed end 120. The adhesive 123 can include, but is not limited to, a conductive adhesive, a non-conductive adhesive, 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 may include, 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 including those known in the art. The metal interlayer 130 allows for better adhesion to 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 may include, 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 by a resistance weld similar to that shown 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 may include, but is not limited to, a conductive adhesive, a non-conductive adhesive, and other adhesives known in the art.

[0092] FIG. 117 illustrates 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 isolated from an outer portion 145 of the fixed end 143. This allows the island 144 to be electrically 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 an SMA material, such as an SMA wire, through a via. The island 144 is disposed on an insulator 146, such as those described herein. The island 144 can be formed using etching techniques, including those known in the art.

[0093] It will be understood that terms such as "top," "bottom," "upper," "lower," and x-, y-, and z-directions used herein are convenient terms to indicate the spatial relationship of parts to one another rather than to any given spatial or gravitational orientation, and are therefore intended to encompass an assembly of components, whether the assembly is oriented in the particular orientation shown in the drawings and described in the specification, or upside-down, or in any other rotational variation thereof.

[0094] It is to 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. Likewise, the term "the present invention" should be understood to encompass a plurality of separate innovations, each of which may 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 accomplished without departing from the spirit and scope of the present invention. Furthermore, 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 is therefore to be understood that the detailed description as set forth above and the accompanying drawings are not intended to limit the scope of the present invention, which should be inferred solely from the following claims and their appropriately interpreted legal equivalents. The technical ideas that can be understood from the above-described embodiments will be described below. [Appendix 1] The beam portion and A fixed end; a load point end, the beam portion being disposed between the fixed end and the load point end; and an SMA material attached to the fixed end and the load point end. [Appendix 2] 2. The actuator of claim 1, comprising a limiter. [Appendix 3] 2. The actuator of claim 1, wherein the load point end is configured to attach the SMA material using a resistance weld. [Appendix 4] 2. The actuator of claim 1, wherein the fixed end is configured to attach the SMA material using a resistance weld. [Appendix 5] 5. The actuator of claim 4, wherein the fixed end includes a flat surface. [Appendix 6] 6. The actuator of claim 5, wherein the SMA material is attached to the flat surface by the resistance weld. [Appendix 7] 7. The actuator of claim 6, wherein an adhesive is disposed on the resistance weld and at least a portion of the flat surface. [Appendix 8] 6. The actuator of claim 5, further comprising a metallic intermediate layer disposed on the flat surface. [Appendix 9] 4. The actuator of claim 3, wherein the fixed end includes a flat surface. [Appendix 10] 10. The actuator of claim 9, wherein the SMA material is attached to the flat surface by the resistance weld. [Appendix 11] 11. The actuator of claim 10, wherein an adhesive is disposed on the resistance weld and at least a portion of the planar surface. [Appendix 12] 10. The actuator of claim 9, further comprising a metallic intermediate layer disposed on the planar surface. [Appendix 13] 11. The actuator of claim 10, further comprising an island formed on an opposite side of the fixed end from the resistance weld, the island being electrically coupled to the SMA material. [Appendix 14] 2. The actuator of claim 1, wherein the beam portion includes a shaped offset. [Appendix 15] 15. The actuator of claim 14, comprising a limiter configured adjacent the shaped offset. [Appendix 16] 16. The actuator of claim 15, wherein the limiter is formed as part of the base. [Appendix 17] 2. The actuator of claim 1, wherein the SMA material is an SMA wire. [Appendix 18] 2. The actuator of claim 1, comprising one or more load point extensions. [Appendix 19] 19. The actuator of claim 18, wherein the one or more load point extensions are formed at an angle to the beam portion. [Appendix 20] 19. The actuator of claim 18, wherein the one or more load point extensions are formed parallel to the beam portion. [Appendix 21] With the base, and one or more bimorph arms, the one or more bimorph arms comprising: The beam portion and A fixed end; a load point end, the beam portion being disposed between the fixed end and the load point end; and an SMA material attached to said fixed end and said load point end. [Appendix 22] 22. The actuator of claim 21, wherein the SMA material of the one or more bimorph arms is SMA wire. [Appendix 23] 22. The actuator of claim 21, wherein the bimorph arm is integrally formed with the base. [Appendix 24] 22. The actuator of claim 21, wherein at least one of the fixed end and the load point end of the one or more bimorph arms includes a flat surface. [Appendix 25] 25. The actuator of claim 24, wherein the SMA material of the one or more bimorph arms is attached to the flat surface of at least one of the fixed end and the load point end by a resistance weld. [Appendix 26] 26. The actuator of claim 25, wherein an adhesive is disposed on the resistance weld and the flat surface of at least one of the fixed end and the load point end. [Appendix 27] 26. The actuator of claim 25, wherein at least one of the fixed end and the load point end includes a metal interlayer disposed on the flat surface. [Appendix 28] 26. The actuator of claim 25, further comprising an island formed on at least one of the fixed end and the load point end opposite the resistance weld, the island being electrically coupled to the SMA material. [Appendix 29] 22. The actuator of claim 21, wherein the beam portions of the one or more bimorph arms include a shaped offset. [Appendix 30] 30. The actuator of claim 29, wherein the one or more bimorph arms include a limiter configured adjacent the shaped offset.

Claims

1. a beam portion, the beam portion including a shaped offset; A fixed end; a load point end configured to move, the beam portion being disposed between the fixed end and the load point end, the beam portion extending longitudinally between the fixed end and the load point end, the shaped offset being offset transversely to the longitudinal direction relative to a remainder of the beam portion, the remainder including a portion between one longitudinal end of the shaped offset and the fixed end and a portion between the other longitudinal end of the shaped offset and the load point end; a first electrical contact disposed on the fixed end; a second electrical contact disposed on the load point end; an SMA material attached to the first electrical contact disposed on the fixed end and the second electrical contact disposed on the load point end.

2. The actuator of claim 1 including a limiter.

3. The actuator of claim 1 , wherein the load point end is configured to attach the SMA material using a resistance weld.

4. The actuator of claim 1 , wherein the fixed end is configured to attach the SMA material using a resistance weld.

5. The actuator of claim 4 , wherein the fixed end includes a flat surface.

6. The actuator of claim 5 , wherein the SMA material is attached to the flat surface by the resistance weld.

7. The actuator of claim 6 , wherein an adhesive is disposed on the resistance weld and at least a portion of the planar surface.

8. The actuator of claim 5 comprising a metallic interlayer disposed over the planar surface.

9. The actuator of claim 3 , wherein the load point end includes a flat surface.

10. The actuator of claim 9 , wherein the SMA material is attached to the flat surface by the resistance weld.

11. The actuator of claim 10 , wherein an adhesive is disposed on the resistance weld and at least a portion of the planar surface.

12. The actuator of claim 9 comprising a metallic interlayer disposed over the planar surface.

13. 11. The actuator of claim 10, further comprising an island formed on the fixed end opposite the resistance weld, the island being electrically coupled to the SMA material.

14. The actuator of claim 1 comprising a limiter configured adjacent the contoured offset.

15. The actuator of claim 14 , wherein the limiter is formed as part of a base.

16. The actuator of claim 1 , wherein the SMA material is an SMA wire.

17. The actuator of claim 1 comprising one or more load point extensions.

18. The actuator of claim 17 , wherein the one or more load point extensions are formed at an angle to the beam portion.

19. The actuator of claim 17 , wherein the one or more load point extensions are formed parallel to the beam portion.

20. With the base, and one or more bimorph arms, the one or more bimorph arms comprising: a beam portion, the beam portion of the one or more bimorph arms including a shaped offset; A fixed end; a load point end configured to move, the beam portion being disposed between the fixed end and the load point end, the beam portion extending longitudinally between the fixed end and the load point end, the shaped offset being offset transversely to the longitudinal direction relative to a remainder of the beam portion, the remainder including a portion between one longitudinal end of the shaped offset and the fixed end and a portion between the other longitudinal end of the shaped offset and the load point end; a first electrical contact disposed on the fixed end; a second electrical contact disposed on the load point end; and an SMA material attached to the first electrical contact disposed on the fixed end and the second electrical contact disposed on the load point end.

21. The actuator of claim 20 , wherein the SMA material of the one or more bimorph arms is an SMA wire.

22. The actuator of claim 20 , wherein the bimorph arm is integrally formed with the base.

23. The actuator of claim 20 , wherein at least one of the fixed end and the load point end of the one or more bimorph arms includes a flat surface.

24. 24. The actuator of claim 23, wherein the SMA material of the one or more bimorph arms is attached to the flat surface of at least one of the fixed end and the load point end by a resistance weld.

25. 25. The actuator of claim 24, wherein an adhesive is disposed on the resistance weld and the flat surface of at least one of the fixed end and the load point end.

26. 25. The actuator of claim 24, wherein at least one of the fixed end and the load point end includes a metal interlayer disposed on the planar surface.

27. 25. The actuator of claim 24, further comprising an island formed on at least one of the fixed end and the load point end opposite the resistance weld, the island being electrically coupled to the SMA material.

28. The actuator of claim 20 , wherein the one or more bimorph arms include a limiter configured adjacent the shaped offset.

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