A shape memory actuator system and control methods thereof are provided that include a shape memory actuator having a body made of shape memory material, with individual power conductors interfaced with a first portion of the body, and one or more individual ground conductors interfaced with a second portion of the body. A power source provides power to the individual power conductors. One or more controllers are provided for pulse controlling or regionally controlling a resistive heating current connection sufficient to impart shape memory to the body or regions of the body between the individual power conductors and the one or more individual ground conductors with the provision that the ground conductors are physically separated from the individual power conductors. Structures of shape memory actuators and methods of control are also provided.

There is provided herein a shape memory alloy wire that includes an alloy composition of CuAlMnNi and excluding grain refiner elements. The alloy composition includes 20 at %-28 at % Al, 2 at %-4 at % Ni, 3 at %-5 at % Mn with Cu as a remaining balance of the alloy composition. The alloy composition is disposed as an elongated wire of at least about 1 meter in length, having a wire diameter of less than about 150 microns. At least about 50 vol % of said alloy composition along said wire length has an oligocrystalline microstructure as-disposed in the wire and without thermal treatment of the wire.

The invention discloses the internal structures and processes to synthesize the structure of self-healing materials, especially metallic materials, metal matrix micro and nanocomposites. Self-healing is imparted by incorporation of macro, micro or nanosize hollow reinforcements including nanotubes, filled with low melting healing material or incorporation of healing material in pockets within the metallic matrix; the healing material melts and fills the crack. In another concept, macro, micro and nanosize solid reinforcements including ceramic and metallic particles, and shape memory alloys are incorporated into alloy matrices, specially nanostructured alloy matrices, to impart self healing by applying compressive stresses on the crack or diffusing material into voids to fill them. The processes to synthesize these self-healing and nanocomposite structures, including pressure or pressureless infiltration, stir mixing and squeeze casting in addition to solid and vapour phase consolidation processes are part of this invention.

A hybrid fluid-flow assembly having a base fitting that has been formed by axial load bulge forming from a sheet of metal, and a custom fitting that has been machined from a shaped-memory alloy. The input port of the custom fitting is connected to the output port of the base fitting by an interference fit. The interference fit may be formed by cooling the custom fitting to a temperature below its transition temperature, deforming the custom fitting so that the diameter of an inlet port is slightly larger than an output port on the base fitting, installing the input port of the custom fitting on the output port of the base fitting, and allowing the custom fitting to warm to room temperature. The shaped-memory alloy swages and coins the outer surface of the base fitting at the interface of the ports, thereby forming a compressive, interference fit.

A method of making a superelastic medical device with a radiopaque marker includes threading a radiopaque marker having an elongated shape over a wire comprising a shape memory alloy. After the threading, the wire is secured in a predetermined configuration to a mandrel. While secured to the mandrel, the wire is heat set in an environment comprising an inert gas so as to impart a memory of the predetermined configuration to the wire and superelastic properties to the shape memory alloy. A superelastic medical device including the radiopaque marker is thus formed.

A device includes a capsule extending longitudinally from a proximal end to a distal end and including a channel extending therethrough. The capsule is releasably coupled to a proximal portion of the device. Device also includes a first arm rigidly fixed to the distal end of the capsule to extend distally therefrom. In addition, Device includes a second arm, a proximal end of which is slidably received within the capsule so that the second arm is movable between an open configuration, in which the second arm is moved laterally away from the first arm and a distal end of the second arm is moved distally past the distal end of the first arm, and a closed configuration, in which the second arm is moved toward the first arm and the distal end of the second arm is moved proximally toward the distal end of the first arm.

A dental archwire is provided having a pre-set shape including an elongate, curved length approximating the shape of a dental arch and a rectangular cross-section having a first dimension of 0.013-0.021 inch and a second dimension of 0.018-0.026 inch or a circular cross-section of diameter 0.013 through 0.026 inch over at least a portion of the elongate, curved length. The dental archwire in the pre-set shape comprises a hyperelastic, single crystal shape memory alloy that is free of elemental precipitates and is capable of exhibiting greater than a 10 percent strain recovery, a constant force deflection, negligible stress hysteresis, and a binding force to an orthodontic bracket equal or less than 4 N.

A material engagement element sheet formed from a sheet material (10) incorporates a pattern of material engagement element slots (14), each slot containing an array of material engagement elements (20) which have a tapered distal section (30), a flange section (34) and a proximal section (32) which is attached to an edge of the slots in the sheet material.. The material engagement element sheet material may be a single layer of shape memory material, or the sheet material may be a composite of different layers some of which may include pre-strained shape memory materials with distinguishable activation parameters. The material engagement element slot configuration allows for the simultaneous processing of the material engagement elements. The material engagement elements may be processed such that they are in a state that is substantially perpendicular to the surface of the material engagement element sheet. The configuration of the flexible base material and the pattern of the material engagement element slots may be used in order to manufacture various material engagement element devices including a material engagement element pad device (166), a cylindrical material engagement element device (104, 105), and a spherical material engagement element device (152).

A method for treating a material comprising: applying energy to a predetermined portion of the material in a controlled manner such that the local chemistry of the predetermined portion is altered to provide a predetermined result. When the material is a shape memory material, the predetermined result may be to provide an additional memory to the predetermined portion or to alter the pseudo-elastic properties of the shape memory material. In other examples, which are not necessarily restricted to shape memory materials, the process may be used to adjust the concentration of components at the surface to allow the formation of an oxide layer at the surface of the material to provide corrosion resistance; to remove contaminants from the material; to adjust surface texture; or to generate at least one additional phase particle in the material to provide a nucleation site for grain growth, which in turn, can strengthen the material.

Wire products, such as round and flat wire, strands, cables, and tubing, are made from a shape memory material in which inherent defects within the material are isolated from the bulk material phase of the material within one or more stabilized material phases, such that the wire product demonstrates improved fatigue resistance. In one application, a method of mechanical conditioning in accordance with the present disclosure isolates inherent defects in nickel-titanium or NiTi materials in fields of a secondary material phase that are resistant to crack initiation and/or propagation, such as a martensite phase, while the remainder of the surrounding defect-free material remains in a primary or parent material phase, such as an austenite phase, whereby the overall superelastic nature of the material is preserved.