Abstract: Methods of fabricating a free standing thin film of shape memory alloy material, and products made by the methods. A sacrificial layer of a metallic material is deposited onto the surface of a substrate. Then an amorphous shape memory alloy is sputter deposited onto the outer surface of the sacrificial layer. The sacrificial layer is etched away, leaving the thin film free standing, that is separated from the substrate. The thin film is annealed by heating into a crystalline state, with the annealing step carried out either after the film has been separated from the substrate, or while remaining attached to it.

Abstract: Methods for making thin film multiple layered three-dimensional devices using two-dimensional MEMS techniques for use in a variety of applications including endovascular, endolumenal, intracranial, and intraocular medical applications. In the general method, a thin film first layer of the device material is deposited over a release layer which in turn is deposited on a substrate. An other release layer is deposited on the first device layer, with portions of the other release layer removed, leaving a pattern in the first device layer. In a similar manner a second layer of device material is formed in a pattern overlying the first device layer with portions of the two layers joined together leaving a portion of the release layer between them. The two release layers are removed and the first and second layers of the device material are formed into a three-dimensional shape suitable for the desired end-use application.

Abstract: An SMA actuated miniature latching valve for on and off control of fluid flow. A valve closure includes a poppet for opening and closing the fluid flow path. The poppet is operated responsive to an actuator mechanism which has SMA wires arranged to be actuated by electric resistant heating. Actuation causes different ones of the wires to contract and pull the poppet either toward or away from a valve seat. A latching mechanism comprising a conical spring operates between two bistable positions which hold the poppet either fully open or fully closed without further application of power to the actuators. A method of forming a secure mechanical and electrical connection between an SMA wire end and its support includes the steps of swaging a metal cone between a cone-shaped hole in the support and the wire end.

Abstract: A valve for the control of fluid flow in microsize systems, such as for transfer of small samples of blood for processing. An actuator beam comprised of a microribbon formed of a shape memory alloy is in a normally closed position where inlet and outlet ports of the valve are closed. In this position a compliant member presses against and holds the microribbon, together with a compliant tape carried below the microribbon, against the ports. The valve is actuated by heating the alloy through its crystalline phase change transition temperature. The resulting change of the microribbon to its memory shape moves the microribbon and tape away from the ports, enabling fluid flow through between the ports in a valve-open mode. The microribbon and tape are held in the valve-open mode when the alloy cools below the transition temperature by a force applied from a heat-shrinkable layer carried on the upper side of the microribbon.

Abstract: A method of fabricating ternary TiNi-based alloys to achieve substantially higher phase-change transition temperatures in the resulting SMA materials and which have optimal thermo-mechanical properties. One target is provided which comprises the element Ti, a second target comprises the element Ni and a third target comprises an element which when combined with Ti and Ni can produce a shape memory alloy. The three targets are co-sputtered onto a substrate at rates which are controlled so that the sum of the percentage composition of the elements that are from the left side of the periodic table are substantially 50 atomic percent, and the sum of percentage composition of the elements that are from the right side of the periodic table comprise the remaining 50 atomic percent.

Abstract: A microrelay device formed on a silicon substrate wafer for use in opening and closing a current path in a circuit. A pair of electrically conducting latching beams are attached at their proximal ends to terminals on the substrate. Proximal ends of the beams have complementary shapes which releasably fit together to latch the beams and close the circuit. A pair of shape memory alloy actuators are selectively operated to change shapes which bend one of the beams in a direction which latches the distal ends, or bend the other beam to release the distal ends and open the circuit. The microrelay is bistable in its two positions, and power to the actuators is applied only for switching it open or closed.

Abstract: A method of measuring with high accuracy the composition of shape memory alloy elements that are sputter deposited in thin film form. An element of known composition is polished with a flat surface. An element of unknown composition is sputter deposited onto the surface. Miniature openings are made by photography in the unknown layer, exposing an area of the known substrate. With adjacent areas of the two samples then only microns apart, accurate measurements of the compositions are made by comparing the X-ray spectra resulting from an electron beam scanning across the two areas.

Abstract: A light shutter for controlling a light signal between occluded and uninterrupted states. The shutter has a frame which mounts a beam under compression so that it assumes either of two bi-stable buckled positions. An occluder is mounted on the beam, A shape memory alloy actuator is provided which applies a force transverse on the beam as the actuator is heated to its shape change transition temperature. The transverse force bends the beam, causing it to buckle to the opposite bi-stable position. This moves the occluder into or out of the path of the light signal.

Abstract: A thin film device, such as an intravascular stent, is disclosed. The device is formed of a seamless expanse of thin-film (i) formed of a sputtered nitinol shape memory alloy, defining, in an austenitic state, an open, interior volume, having a thickness between 0.5-50 microns, having an austenite finish temperature Af below 37° C.; and demonstrating a stress/strain recovery greater than 3% at 37° C. The expanse can be deformed into a substantially compacted configuration in a martensitic state, and assumes, in its austenitic state, a shape defining such open, interior volume. Also disclosed is a sputtering method for forming the device.

Abstract: A valve for the control of fluid flow in microsize systems, such as for transfer of small samples of blood for processing. An actuator beam comprised of a microribbon formed of a shape memory alloy is in a normally closed position where inlet and outlet ports of the valve are closed. In this position a compliant member presses against and holds the microribbon, together with a compliant tape carried below the microribbon, against the ports. The valve is actuated by heating the alloy through its crystalline phase change transition temperature. The resulting change of the microribbon to its memory shape moves the microribbon and tape away from the ports, enabling fluid flow through between the ports in a valve-open mode. The microribbon and tape are held in the valve-open mode when the alloy cools below the transition temperature by a force applied from a heat-shrinkable layer carried on the upper side of the microribbon.

Abstract: A method of measuring with high accuracy the composition of shape memory alloy elements that are sputter deposited in thin film form. An element of known composition is polished with a flat surface. An element of unknown composition is sputter deposited onto the surface. Miniature openings are made by photography in the unknown layer, exposing an area of the known substrate. With adjacent areas of the two samples then only microns apart, accurate measurements of the compositions are made by comparing the X-ray spectra resulting from an electron beam scanning across the two areas.

Abstract: A valve and method of operation for controlling the flow of fluid from a pressurized fluid source while maintaining a secure seal against fluid leakage over long periods of time. The valve includes a valve body formed with an inlet channel which extends through a strain concentrating portion. The strain concentrating portion has an ultimate strength less than that of support portions of the body. An actuator applies a load to the valve body sufficient to create a stress which exceeds the ultimate strength of the strain concentrating portion. The strain concentrating portion then fractures into parts separated by a gap. The fracture forms openings from the inlet channel into the gap to create a flow path from the fluid source into an outlet channel.

Abstract: A fabrication system and method of fabrication for producing microelectromechanical devices such as field-effect displays using thin-film technology. A spacer is carried at its proximal end on the surface of a substrate having field-effect emitters with the spacer being enabled for tilting movement from a nested position to a deployed position which is orthogonal to the plane of the substrate. An actuator is formed with one end connected with the substrate and another end connected with spacer. The actuator is made of a shape memory alloy material which contracts when heated through the material's phase-change transition temperature. Contraction of the actuator exerts a pulling force on the spacer which is tilted to the deployed position. A plurality of the spacers are distributed over the area of the display. A glass plate having a phosphor-coated surface is fitted over the distal ends of the deployed spacer.

Abstract: A release mechanism employing an actuating element of a shape memory alloy material. When the actuating element is heated through its phase-change transition temperature it applies a force which moves a latch to a position which activates the higher energy stored in a drive spring for moving a retaining element out of engagement with a structure. A detent when in a captured position releasably holds the retaining element in its locked position, and the detent is moved from a captured position to a retracted position to release the retaining element when the latch is moved by the actuating element.

Abstract: A sub-miniature valve which provides an actuator of shape memory alloy film coupled so as to move a poppet adjacent to a valve port. The shape memory alloy film actuator is thermally cycled through its phase change transition temperature, resulting in either a contraction or elongation of the actuator. This causes the poppet to move relative to the port and either increase or decrease fluid flow. The shape memory alloy film is biased toward its deformed position when cooled below its transition temperature. The valve can be electrically operated with commonly available voltages, including those used for micro-electronics. The relatively large forces and displacements achieved using the shape memory alloy film provide less restriction and greater flow than in other similarly sized valves.

Abstract: A non-explosive separation device for releasably holding together components of equipment or apparatus which are to be separated under controlled conditions. The separation device and method of operation includes a retaining element having a strain concentrated portion which completely cleaves when strained at a predetermined magnitude. Strain is applied to the retaining element by an actuating element which is comprised of a solid state phase change material having a shape memory. The actuating element is deformed to an armed shape at a temperature below the phase-change transition temperature. The device is activated by heating the actuating element through its transition temperature so that it recovers toward its memory shape. The retaining element is strained beyond its ultimate strength so that it cleaves at the strain concentrated portion.

Abstract: A tactile stimulator array system and method of operational incorporating a plurality of tactile elements having touch-stimulating portions which are positioned through corresponding openings formed in a touch plate. The tactile elements are moved by actuator wires which are formed of a shape-memory alloy material. Electrical control signals from a programmed computer system heat individual wires through the materials phase change transition temperature so that the wires contract to their memory shapes and raise the elements. The touch-stimulating portions then extend above the touch plate where they can be sensed by the user.

Abstract: A non-explosive separation device for releasably holding together components of equipment or apparatus which are to be separated under controlled conditions. The separation device and method of operation includes a retaining element having a strain concentrated portion which completely cleaves when strained at a predetermined magnitude. Strain is applied to the retaining element by an actuating element which is comprised of a solid state phase change material having a shape memory. The actuating element is deformed to an armed shape at a temperature below the phase-change transition temperature. The device is activated by heating the actuating element through its transition temperature so that it recovers toward its memory shape. The retaining element is strained beyond its ultimate strength so that it cleaves at the strain concentrated portion.

Abstract: A method of producing an integral piece of thermo-sensitive material, which is responsive to a shift in temperature from below to above a phase transformation temperature range to alter the material's condition to a shape-memory condition and move from one position to another. The method is characterized by depositing a thin film of shape-memory material, such as Nickel titanium (Ni-Ti) onto a substrate by vacuum deposition process such that the alloy exhibits an amorphous non-crystalline structure.

Abstract: A rotary actuator which provides a differential pulley pair having a shape memory alloy wire. The shape memory alloy wire is thermally cycled through its phase change transition temperature and contracts. Tension forces applied by the ends of the wires to opposite sides of the pulley pair result in a net torque which causes relative rotation between the pulley pair and a reference base. The large mechanical advantage of the differential pulley converts a large force working through a small distance into a relatively large angular rotation.