Shape memory alloy actuator and method thereof

Abstract

To provide an improved bimorph actuator.SOLUTION: SMA actuators and related methods are described. One embodiment of an actuator includes: a base; a plurality of buckle arms; and at least a first shape memory alloy wire coupled with a pair of buckle arms of the plurality of buckle arms. Another embodiment of an actuator includes a base and at least one bimorph actuator including a shape memory alloy material. The bimorph actuator is attached to the base.SELECTED DRAWING: Figure 89

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of and priority to U.S. Provisional Application No. 63 / 090,569, filed October 12, 2020, and U.S. Patent Application No. 17 / 207,530, filed March 19, 2021, the disclosures of all of which are incorporated herein by reference in their entireties.

[0002] FIELD OF THE INVENTION Embodiments of the present invention relate to the field of shape memory alloy systems, and more particularly to the field of shape memory alloy actuators and related methods. [Background technology]

[0003] Shape memory alloy ("SMA") systems have movable assemblies or structures that can be used, for example, with camera lens elements 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 a 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 and support assemblies are connected by four shape memory alloy (SMA) wires extending between them. Each of the SMA wires has one end attached to the support assembly and an opposite end attached to the movable assembly. Applying an electrical drive signal to the SMA wires actuates the suspension. However, these types of systems suffer from system complexity, resulting in bulky systems requiring large footprints and large height clearances. Additionally, current systems are unable to provide a high Z stroke range in a small, low-profile footprint. Summary of the Invention

[0004] An SMA actuator and related 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.

[0005] 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 limitation, in the figures of the accompanying drawings, in which like reference numerals refer to similar elements and in which: [Brief explanation of the drawings]

[0006] [Figure 1a] FIG. 1 illustrates a lens assembly including an SMA actuator configured as a buckle actuator, according to one embodiment. [Figure 1b] FIG. 1 illustrates an SMA actuator according to one embodiment. [Figure 2] FIG. 1 illustrates an SMA actuator according to one embodiment. [Figure 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. [Figure 5] FIG. 1 illustrates an SMA actuator according to one embodiment, including a sensor. [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. 1 is a side view of a section of an SMA actuator according to one embodiment. [Figure 8] 1A-1C 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] 1A-1C are diagrams of bimorph actuators according to some embodiments. [Figure 11b] 1A-1C are diagrams of bimorph actuators according to some embodiments. [Figure 11c] 1A-1C are diagrams of bimorph actuators according to some embodiments. [Figure 12] FIG. 1 illustrates an embodiment of a bimorph actuator, according to one embodiment. [Figure 13] 1A and 1B illustrate cross sections of end pads of a bimorph actuator according to one embodiment. [Figure 14] FIG. 10 illustrates a cross section of a central power pad of a bimorph actuator according to 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. 1 is a side view of an SMA actuator including two buckle actuators according to one embodiment. [Figure 18] FIG. 1 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. [Figure 23] FIG. 1 illustrates an SMA actuator including two buckle actuators and a coupler according to one embodiment. [Figure 24] FIG. 1 is an exploded view of an SMA system including an SMA actuator including a buckle actuator with a laminate hammock, according to one embodiment. [Figure 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] 1A-1C illustrate laminated crimp connections for an SMA actuator according to one embodiment. [Figure 29] FIG. 10 shows an SMA actuator including a buckle actuator with a laminate hammock. [Figure 30] FIG. 1 is an exploded view of an SMA system including an SMA actuator including a buckle actuator according to one embodiment. [Figure 31] FIG. 1 illustrates an SMA system including an SMA actuator including a buckle actuator according to one embodiment. [Figure 32] 1A-1C illustrate SMA actuators including buckle actuators according to one embodiment. [Figure 33] 10A-10C illustrate two-yoke captured joints of a pair of buckle arms of an SMA actuator according to one embodiment. [Figure 34]FIG. 10 illustrates a resistance weld crimp for an SMA actuator according to one embodiment, used to attach the SMA wire to the buckle actuator. [Figure 35] FIG. 10 illustrates an SMA actuator including a buckle actuator with a two-yoke capture joint. [Figure 36] FIG. 1 illustrates an SMA bimorph liquid lens according to one embodiment. [Figure 37] 1A and 1B are diagrams illustrating 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. [Figure 40] FIG. 1 illustrates an SMA actuator with a bimorph actuator according to one embodiment. [Figure 41] FIG. 10 shows the length of the bimorph actuator and the location of the bonding pads where the SMA wire extends the wire length beyond the bimorph actuator. [Figure 42] FIG. 1 is an exploded view of an SMA system including a bimorph actuator according to one embodiment. [Figure 43] FIG. 1 is an exploded view of a subsection of an SMA actuator according to one embodiment. [Figure 44] FIG. 1 illustrates a subsection of an SMA actuator according to one embodiment. [Figure 45] FIG. 1 illustrates a five-axis sensor shifting system according to one embodiment. [Figure 46] FIG. 1 illustrates an exploded view of a five-axis sensor-shifting system in accordance with one embodiment. [Figure 47] FIG. 10 illustrates an SMA actuator including a bimorph actuator incorporated into this circuit for all motions, according to one embodiment. [Figure 48]FIG. 1 illustrates an SMA actuator according to one embodiment, including a bimorph actuator incorporated into the circuit for all movements. [Figure 49] FIG. 1 illustrates a cross section of a five-axis sensor shifting system according to one embodiment. [Figure 50] FIG. 1 illustrates an SMA actuator according to one embodiment including a bimorph actuator. [Figure 51] 1A and 1B 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 configured as a box bimorph autofocus according to one embodiment. [Figure 53] 1A and 1B illustrate an SMA actuator including a bimorph actuator according to one embodiment. [Figure 54] 1A and 1B illustrate an SMA actuator including a bimorph actuator according to one embodiment. [Figure 55] 1A and 1B illustrate 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-shifting 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] 1A-1C illustrate box bimorph actuator components 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 used 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. 10 illustrates exemplary dimensions for a bimorph actuator of an SMA actuator according to one embodiment. [Figure 89] FIG. 1 is a first diagram of a bimorph actuator according to one embodiment. [Figure 90] FIG. 2 is a second view of an exemplary bimorph actuator according to an embodiment. [Figure 91] 1 is a perspective view of an exemplary bimorph actuator according to an embodiment. FIG. [Figure 92] 1A-1C illustrate SMA wires of an exemplary bimorph actuator according to an embodiment. [Figure 93] A diagram illustrating current flow paths in an exemplary bimorph actuator 9310, according to an embodiment. [Figure 94] 1A-1C illustrate an exemplary bimorph actuator including a single, unanchored load point end, according to an embodiment. [Figure 95] 1A-1C illustrate an exemplary bimorph actuator including a single, unanchored load point end, according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] Described herein are embodiments of SMA actuators that include a small footprint and provide a high actuation height, e.g., movement in the positive z-axis direction (z-direction), referred to herein as z-stroke. Examples of SMA actuators include SMA buckle actuators and SMA bimorph actuators. SMA actuators can be used to mechanically impact two surfaces to produce the vibration sensation typically found in haptic feedback sensors and devices, as well as other systems in which actuators are used, in many applications, including, but not limited to, lens assemblies, microfluidic pumps, sensor shifters, optical image stabilization, optical zoom assemblies, as autofocus actuators, and other systems. For example, actuator embodiments described herein can be used as haptic feedback actuators for use in mobile phones or wearable devices configured to provide users with alerts, notifications, warnings, touch areas, or press-button responses. Furthermore, two or more SMA actuators can be used to achieve larger strokes in a system.

[0008] 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 larger 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 larger in one direction than another; for example, the length of the SMA actuator is 0.5 millimeters larger than the width.

[0009] 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 actuators 102 are coupled to a base 101. As shown in FIG. 1b, SMA wire 100 is attached to buckle actuators 102 such that when SMA wire 100 is actuated and contracts, this causes buckle actuators 102 to latch and at least a central portion 104 of each buckle actuator 102 to move in a z-stroke direction, e.g., the positive z-direction, as indicated by arrow 108. According to some embodiments, SMA wire 100 is actuated when an electric current is supplied to one end of the wire, which passes through a wire holder, such as crimp structure 106. The electric current flows through SMA wire 100, heating it due to the inherent resistance of the SMA material from which SMA wire 100 is made. The other side of the SMA wire 100 has a wire holder, such as a crimp structure 106, to which the SMA wire 100 is connected to complete the circuit to ground. Heating the SMA wire 100 to a sufficient temperature changes the unique material properties from a martensitic to an austenitic crystalline structure, causing the wire to change length. Varying the current changes the temperature of the wire, and therefore its length, which is used to activate and deactivate the actuator to control its movement 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.

[0010] 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.

[0011] FIG. 3 shows 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 302 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 buckle actuator 302 is buckled and moves in the z-stroke direction, e.g., the positive z-direction. The return spring 308 is configured to apply a force to the lens carriage 306 in a direction opposite to the z-stroke direction, using techniques including those known in the art. According to various embodiments, the return spring 308 is configured to move the lens carriage 306 in the opposite direction of the z-stroke when the tension in the SMA wire decreases as the SMA wire comes to a stop. 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.

[0012] 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.

[0013] FIG. 6 shows a top view and a side view of an SMA actuator 602 configured as a buckle actuator according to one embodiment, with a lens carriage 604 attached. FIG. 7 shows a side view of a section of the SMA actuator 602 according to the embodiment shown in FIG. 6. According to the embodiment shown in FIG. 7, the SMA actuator 602 includes a slide base 702. According to one embodiment, the slide base 702 is formed from a metal, such as stainless steel, using techniques including those known in the art. However, one skilled in the art will understand that other materials can be used to form the slide base 702. Additionally, the slide base 702 according to some embodiments includes a spring arm 612 coupled to the SMA actuator 602. According to various embodiments, the spring arm 612 is configured to serve two functions. First, it serves to 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 downward, for example, in the negative z-direction, after the SMA wire 602 has moved the SMA actuator 602 in the z-stroke direction, i.e., 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.

[0014] 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. Additionally, the buckle actuator 710 includes a buckle arm 610 and one or more wire retainers 606. According to the embodiment shown in FIGS. 6 and 7 , the buckle actuator 710 includes four wire retainers 606. Each of the four wire retainers 606 is configured to receive an end of an SMA wire 608 and hold the SMA wire 608 so that the SMA wire 608 is attached to the buckle actuator 710. In various embodiments, the four wire retainers 606 are crimps configured to clamp a portion of the SMA wire 608 to attach the wire to the crimp. Those 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, soldering, and mechanical attachment. A smart memory alloy ("SMA") wire 608 extends between the pair of wire holders 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 holders 606 toward each other. According to various embodiments, the SMA wire 608 is electrically actuated when a current is applied to the SMA wire 608, causing the buckle arms 610 to move and control their positions. The SMA wire 608 stops when the current is removed or falls below a threshold. This causes the pair of wire holders 606 to move apart, and the buckle arms 610 to move in the opposite direction from when 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 at 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 to 12 degrees relative to the slide base 702, according to various embodiments.

[0015] 6 and 7, the SMA actuator 602 also includes a slide bearing 706 configured between the slide base 702 and the wire holder 606. The slide bearing 706 is configured to minimize any friction between the slide base 702 and the buckle arms 610 and / or wire holder 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.

[0016] 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.

[0017] FIG. 8 shows multiple views of one embodiment of a buckle actuator 802 relative to the x-axis, y-axis, and z-axis. 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 to one another 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 on, 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 the 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 directly act on a feature of the lens carriage to lift it.

[0018] 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 skilled 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, which is 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 urge the bimorph actuators 902 back to their initial, rest position. The return spring can be configured, as described herein, to help urge the bimorph actuators back down to their initial, rest position. The small footprint of bimorph actuators allows for the fabrication of SMA actuators with reduced footprints compared to current actuator technologies.

[0019] 10 shows a cutaway view of an autofocus assembly including an SMA actuator, according to one embodiment, that includes 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 that includes 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 multiple electrical traces in the spring arm of the movable spring 1006 of the optical image stabilization assembly.

[0020] 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, such as SMA ribbon 1106b (e.g., as shown in the perspective view of the bimorph actuator including an SMA ribbon according to an embodiment of FIG. 11b) or SMA wire 1106a (e.g., as shown in the cross section of the 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. According to various embodiments, the contacts 1110 (e.g., as shown in FIGS. 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 50 milliNewton ("mN") bias force, as shown in FIG. 11c, is used as part of a lens assembly. According to some embodiments, the use of a bimorph actuator 1102 with a lens greater than 1 millimeter generates a larger stroke but less 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 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.

[0021] FIG. 12 shows a diagram of one embodiment of a bimorph actuator, according to one embodiment. The embodiment shown in FIG. 12 includes a central feed 1204 for applying 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 the beam 1206 or base metal with return paths 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 deactivated. This results in faster wire deactivation and actuator response times. The thermal profile of the SMA wire or ribbon is improved. For example, the thermal profile is more uniform, ensuring a higher total current can be delivered to the wire. Without a uniform heat sink, sections of the wire, such as the center region, can overheat and become damaged, thus requiring reduced current and reduced motion for reliable operation. 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 movement and the ability to operate at higher translation frequencies.

[0022] 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. Disposed on top of the beam 1206 is an insulator 1210, such as those described herein. The insulator 1210 is configured with one or more openings or vias 1212 to provide electrical access to the beam 1206, for example, to couple the ground section 1214b of the contact layer 1214 and to provide contact 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 those described herein, is disposed over the contact layer 1214 to electrically isolate the contact layer except for portions of the contact layer 1214 where electrical coupling is desired (e.g., one or more contacts).

[0023] FIG. 13 illustrates an end pad cross section of a bimorph actuator according to one embodiment, such as that shown in FIG. 12. As described above, end pad 1203 is electrically isolated from the remainder of contact layer 1214 by a gap 1222 formed between end pad 1203 and contact layer 1214. The gap is formed, according to some embodiments, using etching techniques, including those known in the art. End pad 1203 includes a via section 1224 configured to electrically couple end pad 1203 to beam 1206. Via section 1224 is formed in via 1212 formed in insulator 1210. SMA material 1202 is electrically coupled to end pad 1213. SMA material 1202 can be electrically coupled to end pad 1213 using techniques including, but not limited to, soldering, resistance welding, laser welding, and direct plating.

[0024] Figure 14 shows a cross section of a center feed of a bimorph actuator according to one embodiment as shown in Figure 12. The center feed 1204 is electrically coupled to a power source through contact layer 1214 and is electrically and thermally coupled to the center metal 1208 by a via section 1226 of the center feed 1204 formed in a via 1212 formed in the insulator 1210.

[0025] 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.

[0026] 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 so that they use their motions to act in opposition to 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.

[0027] 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 on the outer surfaces of the two buckle actuators. According to various embodiments, the hammock portion 1308 of each SMA actuator 1302, 1304 is configured to carry an object that is acted upon by one or more buckle actuators 1302, 1304, such as a portion of a lens carriage 1306 that is moved by the buckle actuators using techniques including those described above.

[0028] 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 cause movement of an object such as a lens carriage in the positive z-direction, or upward direction.

[0029] 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 cause movement of an object such as a lens carriage in the negative z-direction, or downward direction.

[0030] 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 shows an SMA actuator including two buckle actuators according to one embodiment including a base portion and a cover portion.

[0031] 21 shows an SMA actuator including two buckle actuators according to one embodiment. In some embodiments, the buckle actuators 1902, 1904 are positioned relative to one another such that the hammock portion 1908 of the first buckle actuator 1902 is rotated approximately 90 degrees from the hammock portion of the second buckle actuator 1904. The 90-degree configuration allows for pitch and roll rotation of an object such as the lens carriage 1906, which allows for better control 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.

[0032] An embodiment of an SMA actuator including two buckle actuators eliminates the need for 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 including two buckle actuators have lower hysteresis than those including return springs, which lends to more precise position control. In some embodiments, such as the embodiment shown in FIG. 22, an SMA actuator including two buckle actuators 2202, 2204 provides two-axis tilt using differential power to the left SMA wire 2218a and 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 effect tilting motion. For example, by 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 tilt in either axis of motion, or can be adjusted to eliminate any tilt between the lens and sensor for better dynamic tilt, resulting in better image quality across all pixels.

[0033] 23 shows 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 to a second buckle actuator 2304 using a coupler such as 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 moving payload, such as a lens or lens assembly, is attached to a lens carriage 2306 configured to be placed on the sliding base of the first buckle actuator 2302.

[0034] 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 the stroke of the other SMA actuator comprising 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 downward when the power signal is removed from the SMA actuator. Equal and opposite power signals can be applied to the SMA wires of the first buckle actuator 2302 and the second buckle actuator 2304. This can allow the SMA actuators to move in the positive z-direction with one buckle actuator and in the negative z-direction with one buckle actuator, allowing for precise control of the position of the SMA actuators. 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.

[0035] 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 buckle actuator pairs to achieve a desired stroke greater than that of a single SMA actuator.

[0036] 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, in some embodiments, is configured for use with one or more camera lens elements as an autofocus drive mechanism. As shown in FIG. 24 , the SMA system, according to various embodiments, includes a return spring 2403 configured to move the lens carriage 2405 in the opposite direction of the z-stroke when tension in the SMA wire 2408 is reduced as the SMA wire 2408 comes to a stop. 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.

[0037] As shown in Figure 24, sliding base 2401 is positioned on 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, an additional SMA system, or other component. Figure 25 shows an SMA system 2501 including an SMA actuator that includes buckle actuator 2402 with a laminate hammock, according to one embodiment.

[0038] 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 2408 is actuated and deactuated as described herein. The SMA wire 2408 is attached to the buckle actuator using a laminate mold crimp connection 2412. According to the embodiment shown in FIG. 26, the buckle arms 2404 are connected to each other through a central portion, such as a laminate hammock 2406. According to various embodiments, the laminate hammock 2406 is configured to carry an object that the buckle actuator acts on, such as a portion of a lens carriage that the buckle actuator moves using techniques including those described herein.

[0039] FIG. 27 shows 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.

[0040] 28 shows a laminated crimp connection for an SMA actuator according to one embodiment. The laminated 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 laminated crimp connection 2412 includes a laminate formed from one or more layers of insulation and one or more layers of conductive layers formed over the crimp.

[0041] 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 and electrically coupled to one or more signal traces 2415 disposed on the buckle actuator. Deforming the crimp so that it contacts the SMA wire therein also causes the SMA wire to make electrical contact with the conductive layer. Thus, the conductive layer coupled to the one or more signal 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 buckle actuator and attached to the crimp 2412 and buckle actuator using techniques including welding, adhesives, and other techniques known in the art.

[0042] Figure 29 shows an SMA actuator including a buckle actuator with a laminate hammock. As shown in Figure 29, when a power signal is applied, the SMA wire contracts or shortens, moving the buckle arms and laminate hammock in the positive z direction. The laminate hammock, in contact with an object, thereby moves the object, such as a lens carriage, in the positive z direction. When the power signal is reduced or removed, the SMA wire expands, moving the buckle arms and laminate hammock in the negative z direction.

[0043] 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, according to 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 upon the SMA wire being stopped. 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.

[0044] The buckle actuator 3002 includes buckle arms 3004. Each pair of 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.

[0045] As shown in Figure 30, sliding base 3001 is positioned on 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 buckle actuator 3002, according to one embodiment.

[0046] Figure 32 illustrates an SMA actuator including a buckle actuator according to one embodiment. Buckle actuator 3002 includes buckle arms 3004. Buckle arms 3004 are configured to move in the z-axis when SMA wire 3012 is actuated and deactuated as described above. SMA wire 2408 is attached to resistance weld wire crimp 3012. According to the embodiment illustrated in Figure 32, buckle arms 3004 are configured to mate with an object, such as a lens carriage, without a center section using a two-yoke capture joint.

[0047] Figure 33 shows a two-yoke capture joint for a pair of buckle arms of an SMA actuator according to one embodiment. Figure 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. Figure 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 weld to aid in mechanical strength and act as a fatigue strain relief during operation and shock loading.

[0048] Figure 35 shows an SMA actuator including a buckle actuator with two yoke capture joints. As shown in Figure 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.

[0049] 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 circuitry with an SMA actuator 3506. In various embodiments, the SMA actuator includes four bimorph actuators 3508, such as those described herein. The bimorph actuators 3508 are configured to press against a shaped ring 3510 positioned over a flexible membrane 3512. The ring distorts the membrane 3512 / liquid 3514, changing 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 a 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 circuitry including 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 circuitry including the SMA actuators 3506 includes four power circuit control contacts for each SMA actuator and a common return contact.

[0050] Figure 37 shows an SMA bimorph liquid lens viewed from diagonally above according to one embodiment. Figure 38 shows a cross-sectional and bottom view of an SMA bimorph liquid lens according to one embodiment. FIG. 39 illustrates an SMA system including an SMA actuator 3902 with bimorph actuators according to one embodiment. The SMA actuator 3902 includes four bimorph actuators using the techniques described herein. As shown in FIG. 40, which illustrates an SMA actuator 3902 with bimorph actuators according to one embodiment, two of the bimorph actuators are configured as positive z-stroke actuators 3904 and two are configured as negative z-stroke actuators 3906. The opposing actuators 3906, 3904 are configured to control movement in both directions throughout the stroke range. This allows the control cord to be adjusted to compensate for tilt. In various embodiments, two SMA wires 3908 attached to the top of the component enable positive z-stroke displacement. Two SMA wires attached to the bottom of the component enable 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 for the lens carriage 3910 in axes perpendicular to the z-stroke axis, e.g., in the z- and y-axes. 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 for the lens carriage 3910 in axes perpendicular to the z-stroke axis, e.g., in the x- and y-axes. The bottom spring 3918 is configured to be disposed on a base 3920, such as those described herein.

[0051] 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.

[0052] 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 using 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 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 and a bimorph actuator 4306. The negative actuator signal connection 4302 includes a wire bond pad 4308 for connecting the SMA wire 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. The base 4304, the negative actuator signal connection 4302, and the positive actuator signal connection 4314 are each formed from a metal, such as stainless steel. Connection pads 4322 on each of the base 4304, the negative actuator signal connection 4302, and the positive actuator signal connection 4314 are configured to electrically couple control signals and ground 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 signal connections to electrically couple SMA wires for power signals.

[0053] FIG. 45 illustrates a five-axis sensor shift system according to one embodiment. The five-axis sensor shift system is configured to move an object, such as an image sensor, relative to one or more lenses in five axes, including X / Y / Z translation and pitch / roll tilt. Optionally, the system is configured to use only four axes, including X / Y translation and pitch / roll tilt, with a separate AF on top to perform Z movement. Other embodiments include a five-axis sensor shift system configured to move one or more lenses relative to the image sensor. In some embodiments, a static lens stack is mounted on top of the top cover and inserted inside the ID (without contacting the inside of the orange moving carriage).

[0054] 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 constructed on the bimorph circuit components using techniques including those described herein. The five-axis sensor shifting system includes a movable carriage 4608 configured to hold one or more lenses and an outer housing 4610. The bimorph actuator circuit 4604, according to one embodiment, includes 8-12 SMA actuators, such as those described herein. The SMA actuators are configured to move the movable carriage 4608 in five axes, including x, y, z, pitch, and roll, similar to other five-axis systems described herein.

[0055] FIG. 47 shows an SMA actuator according to one embodiment, including a bimorph actuator integrated into 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 into the circuit for all motions, partially formed to fit inside a corresponding outer housing 4804. FIG. 49 shows a cross section of a five-axis sensor shifting system according to one embodiment.

[0056] Figure 50 shows an SMA actuator 5002 according to one embodiment, which includes a bimorph actuator. The SMA actuator 5002 is configured to move an image sensor, lens, or other various payload 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 payload at different x positions and y axes.

[0057] FIG. 52 illustrates an SMA actuator including a bimorph actuator 5202 according to one embodiment configured as a box bimorph autofocus. Four top- and bottom-mounted SMA bimorph actuators, 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 one embodiment, where two top-mounted bimorph actuators 5302 are configured to push down on one or more lenses. FIG. 54 illustrates an SMA actuator including a bimorph actuator according to one embodiment, where two bottom-mounted bimorph actuators 5402 are configured to push up on one or more lenses. FIG. 55 illustrates an SMA actuator including a bimorph actuator according to one embodiment, where four top- and bottom-mounted SMA bimorph actuators 5502, such as those described herein, are used to move one or more lenses to provide tilting movement.

[0058] FIG. 56 shows an SMA system including an SMA actuator according to one 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 a lens in the X / Y axes. In some embodiments, the Z-axis motion comes from a separate autofocus, such as those described herein. Four bimorph actuators push on the sides of the autofocus for OIS movement. FIG. 57 shows an exploded view of an SMA system including an SMA actuator 5802 according to one 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 one embodiment, including a bimorph actuator 5806 configured as a two-axis lens-shift OIS. FIG. 59 shows a box bimorph actuator 5802 according to one 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 (e.g., ±200 μm or greater). 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).

[0059] FIG. 60 illustrates an SMA system including an SMA actuator according to one 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 the autofocus and OIS using the techniques described herein. FIG. 61 illustrates an exploded view of an SMA system including an SMA actuator 6202 according to one embodiment, including a bimorph actuator 6204 according to one embodiment, configured as a 5-axis lens shift OIS and autofocus. FIG. 62 illustrates a cross section of an SMA system including an SMA actuator 6202 according to one embodiment, including a bimorph actuator 6204 configured as a 5-axis lens shift OIS and autofocus. FIG. 63 illustrates a box bimorph actuator 6202 according to one 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 a high OIS stroke (e.g., ±200 μm or greater) and a high autofocus stroke (e.g., 400 μm or greater). Additionally, such embodiments can be adjusted to eliminate any tilt, eliminating the need for a separate autofocus assembly.

[0060] 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. Because the circuit assembly moves with the lens carriage, there are flexible sections for low X / Y / Z stiffness. The terminal pads of the circuit are static. The extrusion box can be configured for four or eight bimorph actuators. Thus, the extrusion box can be configured with four bimorph actuators on the sides for OIS that moves in the X and Y axes. The extrusion box can be configured with four bimorph actuators on the top and bottom for autofocus that moves in the z axis. The extrusion box can be configured with eight 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 three-axis tilt (pitch / roof / yaw). Figure 65 shows an exploded view of an SMA system including an SMA actuator 6602 according to an embodiment, including a bimorph actuator 6604 configured as an extruded box. The SMA actuator is therefore configured such that the bimorph actuator acts on the outer housing 6504 to move the lens carriage 6506 using the techniques described herein. Figure 66 shows an SMA system including an SMA actuator 6602 according to an embodiment, including a bimorph actuator configured as an extruded box partially molded to receive a lens carriage 6603. Figure 67 shows an SMA system including an SMA actuator 6602 according to an embodiment, including a bimorph actuator 6604 configured as an extruded box, as manufactured before being molded to fit within the system.

[0061] FIG. 68 shows an SMA system including an SMA actuator 6802 according to one 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. Four bimorph actuators are configured to push on the sides of a 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 one 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 one embodiment, including a bimorph actuator 6806 configured as a three-axis sensor-shifting OIS. FIG. 71 shows the box bimorph actuator 6802 components according to one embodiment used in an SMA system configured as a three-axis lens-shifting OIS during manufacturing 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 one embodiment. Such systems can be configured to have a high OIS stroke (e.g., ±200 μm or greater) and a high autofocus stroke (e.g., 400 μm or greater). Additionally, 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).

[0062] FIG. 73 shows an SMA system including an SMA actuator 7302 according to one embodiment, including a bimorph actuator 7304 configured as a six-axis sensor-shift OIS and autofocus. In some embodiments, the six-axis sensor-shift OIS and autofocus is configured to move a lens in the X, Y, Z, pitch, yaw, and roll 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. 74 shows an exploded view of an SMA system including an SMA actuator 7402 according to one embodiment, including a bimorph actuator 7404 configured as a six-axis sensor-shift OIS and autofocus. FIG. 75 shows a cross-section of an SMA system including an SMA actuator 7402 according to one embodiment, including a bimorph actuator configured as a six-axis sensor-shift OIS and autofocus. FIG. 76 shows a box bimorph actuator 7402 according to one embodiment used in an SMA system configured as a six-axis lens-shift OIS and autofocus, as manufactured before being molded to fit the system. Figure 77 shows a flexible sensor circuit for use in an SMA system configured as a three-axis sensor-shift OIS according to one embodiment. Such a system can be configured to have a high OIS stroke (e.g., ±200 μm or greater) and a high autofocus stroke (e.g., 400 μm or greater). Furthermore, such an embodiment can be adjusted to eliminate any tilt, eliminating the need for a separate autofocus assembly.

[0063] FIG. 78 shows an SMA system including an SMA actuator according to one embodiment, including a bimorph actuator configured as a two-axis camera tilt OIS. In some embodiments, the two-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 overall camera movement relative to the 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 one embodiment, including a bimorph actuator 7904 configured as a two-axis camera tilt OIS. FIG. 80 shows a cross section of an SMA system including an SMA actuator according to one embodiment, including a bimorph actuator configured as a two-axis camera tilt OIS. FIG. 81 shows a box bimorph actuator according to one embodiment used in an SMA system configured as a two-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 two-axis camera tilt OIS, according to one embodiment. Such systems can be configured to have a 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).

[0064] FIG. 83 shows an SMA system including an SMA actuator according to one embodiment, including a bimorph actuator configured as a three-axis camera tilt OIS. In some embodiments, the two-axis camera tilt OIS is configured to move the camera in the pitch / yaw / roll axes. Four bimorph actuators are used to push the top and bottom of the autofocus for full camera movement relative to the OIS pitch and yaw movement using the techniques described herein, and four bimorph actuators are used to push the sides of the autofocus for full camera movement relative to the OIS roll movement using the techniques described herein. FIG. 84 shows an exploded view of an SMA system including an SMA actuator 8402 according to one embodiment, including a bimorph actuator 8404 configured as a three-axis camera tilt OIS. FIG. 85 shows a cross-section of an SMA system including an SMA actuator according to one embodiment, including a bimorph actuator configured as a three-axis camera tilt OIS. FIG. 86 shows a box bimorph actuator used in an SMA system according to one embodiment configured as a three-axis camera tilt OIS, as manufactured before being molded to fit the system. Figure 87 shows a flexible sensor circuit used in an SMA system according to one embodiment configured as a 3-axis camera tilt OIS. Such a system can be configured to have a high OIS stroke (e.g., ±3 degrees or greater). These embodiments are configured to easily integrate with AF designs (e.g., VCM or SMA).

[0065] 88 shows exemplary dimensions of a bimorph actuator for an SMA actuator according to an embodiment. The dimensions are of a preferred embodiment, but one skilled in the art will understand that other dimensions can be used based on the desired characteristics for the SMA actuator.

[0066] 89 shows a first diagram of a bimorph actuator 8980 according to one embodiment. The bimorph actuator 8980 includes a conductive metal base layer 8934 (e.g., a stainless steel layer) and a dielectric layer 8939. The illustrated bimorph actuator 8980 allows for a reduced layer count configuration compared to conventional designs. This reduced layer count improves manufacturing efficiency and reduces raw material costs.

[0067] For purposes of this disclosure, Figure 1 is a view of the dielectric side of bimorph actuator 8980. Bimorph actuator 8980 includes at least one free end (otherwise referred to herein as the "unanchored end"), two free ends 8909, 8910 are illustrated herein. Bimorph actuator 8980 also includes a fixed end 8930. Free end 8910 is connected to fixed end 8930 by bimorph arm 8921. Free end 8908 is connected to fixed end 8930 by bimorph arm 8923.

[0068] According to some embodiments, free end 8908 includes a load point including a contact member 8912 extending from tongue 8907. According to some embodiments, tongue 8907 is constructed largely of stainless steel. Similarly, according to some embodiments, free end 8910 includes a load point including a contact member 8909 extending from tongue 8911. Contact member 8912 can also include a contact material such as stainless steel. Contact member 8912 is configured to engage with any component, for example, a lens carriage or other object. In this configuration, bimorph actuator 8980 is configured to move in the z-direction when actuated and to lift an object, such as a lens carriage, in the z-direction.

[0069] According to some embodiments, bimorph arm 8921 includes one or more SMA materials (e.g., as described herein), such as SMA ribbon or SMA wire. According to some embodiments, the SMA material is attached to bimorph arm 8921 using techniques including those described herein. According to some embodiments, the SMA material is attached to beam 8921 using adhesive film materials, epoxy, or other attachment techniques. Bimorph arm 8921 also includes a conductive metal base layer 8934 and optionally a dielectric layer 8926. Similarly, second bimorph arm 8923 includes a conductive metal base layer and optionally a dielectric layer 8924. Conductive metal base layer 8934 can be formed from a conductive metal, including, but not limited to, stainless steel, copper, copper alloys, gold, nickel, other conductive materials, and combinations thereof.

[0070] In some embodiments, the bimorph arms are configured as beams, such as those described herein. For example, conductive metal base layer 8934 takes the form of a beam-shaped stainless steel base, including those described herein, extending from fixed end 8930 to form free ends 8908, 8910. Dielectric layer 8926 extends along conductive metal base layer 8934 of first bimorph arm 8921. According to some embodiments, SMA material extends on dielectric layer 8926 from first SMA contact 8987 to tongue 8907. The SMA material is attached to first SMA contact 8987 and tongue 8911 using techniques including those described herein. SMA material also extends on dielectric layer 8924 from second SMA contact 8988 to tongue 8907. The SMA material is attached to second SMA contact 8988 and tongue 8907 using techniques including those described herein. In some embodiments, a dielectric layer may also be disposed over the SMA material, which electrically insulates the SMA material from the conductive metal base layer and other conductive components.

[0071] Fixed end 8930 includes a first contact pad 8935 and a second contact pad 8932. First contact pad 8935 is electrically and mechanically coupled to the SMA material of first bimorph arm 8921 via first SMA contact 8987. First contact pad 8935 is configured to be coupled to a current source of SMA material to actuate first bimorph arm 8921 as described herein. Similarly, second contact pad 8932 is electrically and mechanically coupled to the SMA material of second bimorph arm 8923 via second SMA contact 8988. Second contact pad 8932 is configured to be coupled to a current source of SMA material to actuate second bimorph arm 8923 as described herein. According to various examples of the present disclosure, first contact pad 8935 and second contact pad 8932 are gold stainless steel pads. The fixed end 8930 also includes an aperture 8936 configured to receive an anchoring element for attaching the bimorph actuator 8980 to a base. The fixed end 8930 of the bimorph actuator 8980 includes a dielectric layer 8939 and a conductive metal base layer 8934.

[0072] 90 shows a second view of a bimorph actuator 8980, according to embodiments. The bimorph actuator 8980 includes a conductive metal base layer 8934. The bimorph actuator 8980 includes two free ends 8910, 8908 extending from a fixed end 8930 by bimorph arms 8921, 8923, respectively. According to some embodiments, the two free ends 8910, 8908, the bimorph arms 8921, 8923, and a portion of the fixed end 8930 are comprised of a single conductive metal base layer 8906.

[0073] The fixed end 8930 also includes a first conductive metal base element 8931, a second conductive metal base element 8933, and a common conductive metal base layer 8906. The first conductive metal base element 8931, the second conductive metal base element 8933, and the common conductive metal base layer 8906 can be separated on the fixed end 8930 by a gap defined by a dielectric layer 8939. In some embodiments, the gap can be a partially or fully etched gap that exposes the dielectric layer 8939 attached to the first conductive metal base element 8931, the second conductive metal base element 8933, and the common conductive metal base layer 8906. Weld tongues or partial etch features can be applied to the fixed end 8930 or the free ends 8910, 8908.

[0074] The first conductive metal base element 8931 and the second conductive metal base element 8933 are electrically isolated to create an electrical path to the SMA material, as described in further detail below. The common conductive metal base layer 8906 is configured to enable rigidity for assembly and application of the bimorph actuator 8980. In some examples, the first contact pad (shown in FIG. 89 as reference numeral 8935) can be a gold pad plated on the first conductive metal base element 8931. Similarly, the second contact pad (shown in FIG. 89 as reference numeral 8932) can be a gold pad plated on the second conductive metal base element 8933.

[0075] 91 shows a perspective view of a bimorph actuator 8990 according to an embodiment. A first conductive metal base element 8931 and a second conductive metal base element 8933 are electrically separated by a dielectric gap 8939.

[0076] The first contact pad 8935 is configured to be electrically connected to a power source. The first contact pad 8935 is electrically and mechanically connected to the first conductive metal base element 8931. The first conductive metal base element 8931 is electrically and mechanically connected to the first contact 8937. The first contact 8937 is configured to be connected to the SMA material 8925 of the first bimorph arm 8921. In other words, the first conductive metal base element 8931 is configured to function as an electrical pathway to the SMA material 8925 of the first bimorph arm 8921.

[0077] The current causes the SMA material 8925 to heat up, which results in a contraction in length of the SMA material 8925. In the process, the contraction of the SMA material 8925 lifts the free end 8910 to a plane above the fixed end 8930, effectively raising the first bimorph arm 8921.

[0078] Similarly, the second contact pad 8932 is configured to be electrically connected to a power source. The second contact pad 8932 is electrically and mechanically connected to a second conductive metal base element 8933. The second conductive metal base element 8933 is also electrically and mechanically connected to a second contact element 8938. The second contact element 8938 is connected to the SMA material 8922 of the second bimorph arm 8923. In other words, the second conductive metal base element 8933 is configured to function as an electrical pathway to the SMA material 8922 of the second bimorph arm 8923.

[0079] The current causes the SMA material 8922 to heat up, which results in a contraction in length of the SMA material 8922. In the process, the contraction of the SMA material 8922 lifts the free end 8908 to a plane above the fixed end 8930, effectively raising the first bimorph arm 8921.

[0080] FIG. 92 illustrates SMA materials 8925, 8922 of an exemplary bimorph actuator 8990, according to an embodiment. The SMA material 8925 is electrically coupled to the first conductive metal base element 8931 of the fixed end 8930. The SMA material 8925 is also electrically coupled to the conductive metal base layer of the tongue 8907 of the free end 8910. According to some embodiments, the SMA material 8922 and the SMA material 8925 are connected in series. Current flows in direction 8995 into the common conductive metal base layer 8906 of the fixed end, through the first bimorph arm 8921, and to the conductive metal base of the tongue 8910. The current flows in direction 8997, through the SMA material 8925, to the first conductive metal base element 8931, and in direction 8993 to the first contact pad 8935.

[0081] The SMA material 8922 is electrically coupled to the second conductive metal base element 8933 of the fixed end 8930. The SMA material 8922 is also electrically coupled to the conductive metal base of the tongue 8907 of the free end 8908. Current flows into the second contact pad 8932 of the fixed end in direction 8991, through the second conductive metal base element 8933, and to the SMA material 8922. Current flows through the SMA material 8922 to the conductive metal base of the tongue 8911. Current flows from the tongue 8911 through the second bimorph arm 8923 to the common conductive metal base layer 8906 in direction 8994. Current flows through the SMA material 8922 to the conductive metal base of the tongue 8911 in direction 8992 and toward the second contact pad 8935 in direction 8991.

[0082] According to embodiments, the proximity of the common conductive metal base layer 8906 to SMA material 8922, 8925, such as SMA wire, along the entire length of the SMA material allows the wire to cool faster when the current is turned off, i.e., the bimorph actuator is deactivated. This results in faster wire deactivation and actuator response time. The thermal profile of the SMA wire or ribbon is improved. For example, the thermal profile is more uniform, ensuring higher total current can be delivered through the wire.

[0083] 93 shows a current flow path of an exemplary bimorph actuator 9310, according to an embodiment. The bimorph actuator 9310 includes a first bimorph arm 9321, which includes one or more SMA materials 9325, such as SMA ribbons or SMA wires. The SMA material 9325 can be attached to a beam of the first bimorph arm 9321. The first bimorph arm 9321 can also include a conductive metal base layer and optionally a dielectric layer.

[0084] The SMA material 9325 is electrically coupled to the first conductive metal base element 9337 of the fixed end 9330. The SMA material 9325 is also electrically coupled to the conductive metal base layer of the tongue 9311 of the free end 9310. Current flows in the first conductive metal base element 9337 of the fixed end in direction 9301. Electrically coupling the SMA material 9325 to the conductive metal base of the tongue 9311 provides a circuit return path in direction 9303. Current flows from the first bimorph arm 9321 in direction 9305 within the single conductive metal base layer.

[0085] The bimorph actuator 9310 includes a second bimorph arm 9323, which includes one or more SMA materials 9327, such as SMA ribbons or SMA wires. The SMA material 9327 may be attached to a beam of the second bimorph arm 9323. The second bimorph arm 9323 may also include a conductive metal base layer and optionally a dielectric layer.

[0086] The SMA material 9327 is electrically coupled to a second conductive metal base element 9338 of the fixed end 9330. The SMA material 9327 is also electrically coupled to the conductive metal base layer of the tongue 9313 of the free end 9312. Current flows from the common conductive metal base layer 9338 of the fixed end to the SMA material 9327 in direction 9307. Electrically coupling the SMA material 9327 to the conductive metal base of the tongue 9313 provides a circuit return path in direction 9309. Some examples show two loose load point ends, one connected to each bimorph arm. The present disclosure also provides for a single loose load point end attached to two or more bimorph arms.

[0087] FIG. 94 illustrates an exemplary bimorph actuator 9400 including a single, loose load point end 9410, according to an embodiment. The single, loose load point end 9410 can include contact members 9408, 9409 extending from a conductive metal base layer of a tongue 9411. The contact members 9408, 9409 are configured to engage a component, such as a lens carriage. The bimorph actuator 9400 includes a first bimorph arm 9421, which includes one or more SMA materials 9425, such as SMA ribbons or SMA wires. The SMA material 9425 can be attached to a beam of the first bimorph arm 9421. The first bimorph arm 9421 can also include a conductive metal base layer and, optionally, a dielectric layer.

[0088] 93 , the SMA material 9425 can be electrically coupled to the conductive metal base element of the fixed end. The SMA material 9425 is also electrically coupled to the conductive metal base layer of the tongue 9411 of the single, unfixed load point end 9410. The bimorph actuator 9400 can also include a second bimorph arm 9423. The second bimorph arm 9423 includes one or more SMA materials 9422, such as SMA ribbons or SMA wires. The SMA material 9422 can be attached to a beam of the second bimorph arm 9423. The second bimorph arm 9423 can also include a conductive metal base layer and optionally a dielectric layer.

[0089] The SMA materials 9425, 9422 can be electrically coupled to the conductive metal base element 9411 of the single, free load point end 9410. Current flows from the common conductive metal base layer of the fixed end to the SMA material 9425 in direction 9401. Electrically coupling the SMA material 9425 to the conductive metal base element 9411 of the single, free load point end 9410 provides a circuit return path to the SMA material 9422 in direction 9402. Current flows from the conductive base element 9411 through the SMA material 9422 to the common conductive metal base layer of the fixed end in direction 9403.

[0090] In this example, the single, loose load point end 9410 eliminates concerns about a separate current flow path with the conductive metal base element 9411. The single, loose load point end 9410 also allows for a larger footprint for the conductive metal base element 9411 and provides a thinner surface post-etch. The exemplary bimorph actuator 9400 consumes less power compared to the previous example due to the shorter electrical path and improved resistance path. The single, loose load point end 9410 also allows for designs incorporating load point structures of various sizes and shapes.

[0091] FIG. 95 illustrates an exemplary bimorph actuator 9500 including a single, loose load point end 9510, according to an embodiment. The single, loose load point end 9510 can include a load point element 9512 extending from a conductive metal base layer of a tongue 9511. The load point element 9512 is configured to engage a component, such as a lens carriage. The load point element 9512 can be made of any material that combines with the conductive metal base layer of the tongue 9511 to enable a low-friction connection between the load point element 9512 and the payload of the engaging component. In some examples, the load point may be constructed predominantly of stainless steel.

[0092] The bimorph actuator 9500 includes a first bimorph arm 9521, which includes one or more SMA materials 9525, such as SMA ribbons or SMA wires. The SMA material 9525 may be attached to a beam of the first bimorph arm 9521. The first bimorph arm 9521 may also include a conductive metal base layer and optionally a dielectric layer.

[0093] 93, the SMA material 9525 is electrically coupled to the conductive metal base element of the fixed end. The SMA material 9525 is also electrically coupled to the conductive metal base layer of the tongue 9511 of the single, unfixed load point end 9510. The bimorph actuator 9500 may also include a second bimorph arm 9523. The second bimorph arm 9523 includes one or more SMA materials 9522, such as SMA ribbons or SMA wires. The SMA material 9522 may be attached to a beam of the second bimorph arm 9523. The second bimorph arm 9523 may also include a conductive metal base layer and optionally a dielectric layer.

[0094] The SMA materials 9525, 9522 are electrically coupled to the conductive metal base element 9511 of the single, free load point end 9510. Current flows in direction 9501 from the common conductive metal base layer of the fixed end to the SMA material 9425. Electrically grounding the SMA material 9525 to the conductive metal base element 9411 of the single, free load point end 9410 provides a circuit return path in direction 9502 to the SMA material 9522. Current flows in direction 9503 from the conductive base element 9511 through the SMA material 9522 to the common conductive metal base layer of the fixed end.

[0095] In some examples of the present disclosure, the load point elements 9512 can be manufactured in a variety of sizes and shapes. In some examples of the present disclosure, the load point elements 9512 can be attached to the loose load point ends 9510 using any method, including, but not limited to, glue, welding, adhesives, etc. Additionally, the load point elements 9512 can be one or more separate pieces. The load point elements 9512 are illustrated on a single loose load point end 9510. Further examples of the present disclosure can include a load point element located on each loose load point end, for example, in FIGS. 88-93 .

[0096] It will be understood that terms such as "top," "bottom," "upper," "lower," and x-, y-, and z-directions used herein are terms of convenience that indicate the spatial relationship of parts to one another rather than to any given spatial or gravitational orientation. These terms are therefore intended to encompass assemblies 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.

[0097] It is 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, it is understood that the term "the present invention" encompasses multiple separate innovations, each of which can be considered a separate invention. While 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 made without departing from the spirit and scope of the present invention. Furthermore, the techniques described herein can be used to create devices having two, three, four, five, six, or more generally, n bimorph and buckle actuators. Therefore, it should be understood that the detailed description and accompanying drawings as set forth above 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.

Claims

1. a fixed end portion including a dielectric layer and a conductive metal base layer, the conductive metal base layer including a first conductive metal base element, a second conductive metal base element, and a common conductive metal base layer that are electrically insulated from each other; a first bimorph arm and a second bimorph arm extending from the fixed end, the first bimorph arm and the second bimorph arm being constructed from the common conductive metal base layer; a first free end extending from the first bimorph arm and a second free end extending from the second bimorph arm, the first free end and the second free end being formed from the common conductive metal base layer and spaced apart from each other; a first SMA material extending between the fixed end and the first free end; a second SMA material extending between the fixed end and the second free end; the first SMA material is electrically coupled to the first conductive metal base element at the fixed end and to the common conductive metal base layer at the first free end; A bimorph actuator, wherein the second SMA material is electrically coupled to the second conductive metal base element at the fixed end and to the common conductive metal base layer at the second free end.

2. A fixed end including a dielectric layer and a conductive metal base layer, the conductive metal base layer including a first conductive metal base element, a second conductive metal base element, and a common conductive metal base layer that are electrically insulated from each other; a first bimorph arm and a second bimorph arm extending from the fixed end, the first bimorph arm and the second bimorph arm being constructed from the common conductive metal base layer; a single unfixed load point end connected to the first bimorph arm and the second bimorph arm, the single unfixed load point end being made of the common conductive metal base layer; a first SMA material extending between the fixed end and the single, unanchored load point end, the first SMA material being electrically coupled to the first conductive metal base element of the fixed end and to the common conductive metal base layer of the single, unanchored load point end; a second SMA material extending between the fixed end and the single, unanchored load point end, the second SMA material being electrically coupled to the second conductive metal base element of the fixed end and to the common conductive metal base layer of the single, unanchored load point end.

3. 3. A bimorph actuator as described in claim 1 or 2, wherein the conductive metal base layer is separated into the first conductive metal base element, the second conductive metal base element, and the common conductive metal base layer by a gap defined by the dielectric layer.

4. 4. The bimorph actuator of claim 3, wherein the gap is a partially or completely etched gap that exposes the dielectric layer attached to the first conductive metal base element, the second conductive metal base element, and the common conductive metal base layer.

5. A bimorph actuator as described in claim 3, wherein the first bimorph arm and the second bimorph arm are composed of the common conductive metal base layer and the dielectric layer.

6. A bimorph actuator as described in claim 1, wherein each of the first free end and the second free end includes a tongue-shaped portion constructed from the common conductive metal base layer and a contact member extending from the tongue-shaped portion.

7. The bimorph actuator of claim 2 , wherein the single, unanchored load point comprises a load point element.

8. A bimorph actuator as described in claim 1 or 2, wherein each of the first SMA material and the second SMA material includes an SMA ribbon or an SMA wire.

9. A bimorph actuator as described in claim 1 or 2, wherein each of the first SMA material and the second SMA material is attached to a corresponding bimorph arm using an adhesive film material.

10. The bimorph actuator of claim 1 or 2, wherein the conductive metal base layer is made of at least one of stainless steel, copper, a copper alloy, gold, and nickel.

11. 3. The bimorph actuator of claim 1, wherein the fixed end includes a first contact pad electrically and mechanically coupled to the first SMA material, the first contact pad being a gold-plated stainless steel pad.

12. 3. The bimorph actuator of claim 1, wherein the fixed end includes a second contact pad electrically and mechanically coupled to the second SMA material, the second contact pad being a gold-plated stainless steel pad.

13. An actuator comprising a dielectric layer and a conductive metal base layer, a fixed end, wherein the conductive metal base layer of the fixed end is separated into a first conductive metal base element, a second conductive metal base element, and a common conductive metal base layer that are electrically insulated from one another by a gap defined by the dielectric layer; a first bimorph arm and a second bimorph arm extending from the fixed end, the first bimorph arm and the second bimorph arm being configured with the common conductive metal base layer and the dielectric layer; a first free end extending from the first bimorph arm and a second free end extending from the second bimorph arm, the first free end and the second free end being formed from the common conductive metal base layer and spaced apart from each other; a first SMA material extending between the fixed end and the first free end, the first SMA material being electrically coupled to the first conductive metal base element of the fixed end and to the common conductive metal base layer of the first free end; a second SMA material extending between the fixed end and the second free end, the second SMA material being electrically coupled to the second conductive metal base element of the fixed end and to the common conductive metal base layer of the second free end; the first conductive metal base element and the second conductive metal base element are configured to be electrically coupled to a power source, whereby the first SMA material and the second SMA material are connected in series between the first conductive metal base element and the second conductive metal base element via the common conductive metal base layer.

14. The actuator of claim 13 , wherein the first conductive metal base element and the second conductive metal base element are electrically isolated.

15. An actuator as described in claim 13, wherein each of the first free end and the second free end includes a tongue-shaped portion constructed from the common conductive metal base layer and a contact member extending from the tongue-shaped portion.

Images