Abstract: An ice making assembly for a refrigerator appliance is provided. The ice making assembly includes a mold body and an ejector. The ejector has a shaft with a central axis that is offset from an axis of rotation of the ejector. The ejector also has a plurality of tines for sweeping through mold volumes of the mold body. Each tine has an arcuate bottom surface.

Abstract: A system for and method of reducing the effects of preheat period variation in shape memory alloy actuation, include sensing the removal of motion delay due to slack, backlash, and/or compliance in the actuator and drive-train of the system, and determining actuator activation, as a result thereof.

Abstract: A shape memory alloy (SMA) driving system includes an SMA wire, a power source, a switch element, a temperature sensor, a pulse generator, and a control unit. The power source is electrically connected to one end of the SMA. The switch element includes an input terminal electrically connected to the other end of the SMA, a grounded output terminal, and a control terminal configured for controlling connection and disconnection between the input terminal and the output terminal. The control unit stores a martensite convert temperature and an austenite convert temperature. The control unit compares a temperature detected by the temperature sensor with the martensite convert temperature and the austenite convert temperature. when the detected temperature is lower than the martensite convert temperature and is higher than the austenite convert temperature, the control unit controls the pulse generator to output a higher duty-cycle signal.

Abstract: An electro-thermal actuator which includes a unit cell comprising at least one thermal bimorph, the thermal bimorph comprising at least two materials of different thermal expansion coefficient bonded together, the unit cell having a first end and a second end; and at least one temperature sensor located on the at least one thermal bimorph for measuring a temperature of the at least one thermal bimorph and determining a position of the unit cell. The basic structure can be expanded to 1-D, 2-D and 3-D positioners. The bimorphs can also be coupled to an active yoke which is in turn anchored to a plate, in order to reduce the parasitic heat effects on displacement of the tip of the bimorph.

Abstract: A shape memory alloy driver comprises a displacement detection portion, a drive control portion, and a compensation calculation portion. The displacement detection portion detects displacement of a shape memory alloy based on a resistance value etc. detected from the shape memory alloy. The drive control portion applies a voltage or current to the shape memory alloy by servo control to thereby displace the shape memory alloy to a target displacement value fed from a microcomputer etc. The compensation calculation portion calculates a compensated displacement value from the detected displacement value and a variation—attributable to the environment temperature—of the drive control value which the drive control portion uses for controlling the voltage or current. Having been fed with the compensated displacement value, the drive control portion varies the drive control value such that the compensated displacement value is equal to the target displacement value.

Abstract: Power-efficient actuator apparatus and methods. In one exemplary embodiment, the actuator assembly utilizes a shape memory alloy (SMA) filament driven by an electronic power source to induce movement in the underlying assembly to actuate a load (e.g., water valve). In addition, a circuit board is included which allows the actuator assembly to be readily incorporated or retrofit into a wide range of systems such that the signal characteristics of the supply line can, among other applications, be conditioned in order to protect the SMA filament. Furthermore, the circuit board can also readily be adapted for use with “green” power sources such as photovoltaic systems and the like. Methods for manufacturing and utilizing the aforementioned actuator assembly are also disclosed.

Abstract: A shape memory alloy actuator system includes a shape memory alloy actuator which has a shape memory alloy wire, a mobile object which is movable, an elastic member, a first regulating member, and a second regulating member, a detecting section which detects a resistance value of the shape memory alloy wire, a calculating section (a computing section) which calculates an electric current applied, an output section, a control section which controls the detecting section, a calculating section, an output section, and a reference resistance value calculating section. The shape memory alloy actuator, the detecting section, the calculating section, the output section, the control section, and the reference resistance value calculating section collectively form a resistance control circuit which carries out a position control of the shape memory alloy actuator.

Abstract: In one example, an actuator mechanism comprising: one or more coils for establishing a magnetic field; a rotating permanent magnet, which has at least one extreme position depending on the magnetic field; and driving members, which are coupled to the permanent magnet and by means of which the members coupled to the actuator mechanism are driven. In another example, an actuator mechanism comprising: one or more wires, which are manufactured of a shape memory alloy that shrinks when heated; and driving members, which are coupled to said wire and by means of which the members connected to the actuator mechanism are driven.

Abstract: An exhaust gas system for an internal combustion engine has a thermoelectric power generator with a hot side and a cold side. The hot side is arranged on the exhaust gas system and is heatable by exhaust gas of the internal combustion engine. A first heat exchanger having a first thermal conductivity is arranged between the hot side and the exhaust gas flow. At least a second thermoelectric power generator is arranged on the exhaust gas system and has a second heat exchanger with a thermal conductivity that is different from the first thermal conductivity. The arrangement of thermoelectric power generators can generate electric power over a significantly wider operating point range of the internal combustion engine.

Abstract: A nonvolatile nano-electromechanical system device is provided and includes a cantilever structure, including a beam having an initial shape, which is supported at one end thereof by a supporting base and a beam deflector, including a phase change material (PCM), disposed on a portion of the beam in a non-slip condition with a material of the beam, the PCM taking one of an amorphous phase or a crystalline phase and deflecting the beam from the initial shape when taking the crystalline phase.

Abstract: An active material actuator adapted for use in a circuit includes an active material member, and a piezoelectric or piezoresistive element or otherwise force sensing device, wherein the element or device is communicatively coupled to the member and operable to vary the current within the circuit when the member is caused to achieve a predetermined stress, such that, in one aspect, the element presents an overload protection mechanism.

Abstract: A MEMS thermal switch is disclosed which couples a hot, expanding beam to a cool flexor beam using a slideably engaged tether, and bends the cool, flexor beam by the expansion of the hot beam. A rigidly engaged tether ties the distal ends of the hot, expanding beam and the cool, flexor beam together, whereas the slideably engaged tether allows the hot, expanding beam to elongate with respect to the cool, flexor beam, without loading the slideably engaged tether with a large shear force. As a result, the material of the tether can be made stiffer, and therefore transmit the bending force of the hot, expanding beam more efficiently to the cool, flexor beam.

Abstract: A shape memory alloy driver comprises a displacement detection portion, a drive control portion, and a compensation calculation portion. The displacement detection portion detects displacement of a shape memory alloy based on a resistance value etc. detected from the shape memory alloy. The drive control portion applies a voltage or current to the shape memory alloy by servo control to thereby displace the shape memory alloy to a target displacement value fed from a microcomputer etc. The compensation calculation portion calculates a compensated displacement value from the detected displacement value and a variation—attributable to the environment temperature—of the drive control value which the drive control portion uses for controlling the voltage or current. Having been fed with the compensated displacement value, the drive control portion varies the drive control value such that the compensated displacement value is equal to the target displacement value.

Abstract: The present invention provides an actuation device having a shape memory alloy component. The present invention utilizes a length contraction occurred to the shape memory alloy component during its phase transformation from martensite to austenite. The length contraction causes a slider, a carrier and a base to move relatively. Also, the present invention utilizes thermal conductivity of the base to speed up heat dissipation of the shape memory alloy component, so that response time for actuating the carrier can be reduced.

Abstract: To provide a shape memory alloy actuator using a shape memory alloy that mechanically restrains a moving body in position to prevent oscillation, the actuator has a moving body pushing member adapted to be capable of abutting to the moving body, a bias spring for the moving body pushing member that exerts an external force on the moving body pushing member in the direction opposite to the direction of change in the shape of a shape memory wire caused by heating, a bias spring for the moving body that exerts an external force on the moving body in the direction same as the direction of change, a first stopper that restricts the movement of the moving body to a predetermined position upon cooling. One end of the shape memory wire is fixed, the other end is mechanically linked with the moving body pushing member.

Abstract: A thermomechanical actuation system and method includes an elongated thermomechanical actuator (TMA), which is contoured so that electrical resistance at a mid-portion of the TMA is less than at end portions thereof. A pulse generator is electrically coupled to the TMA, and is configured to supply excitation pulses to the TMA. The excitation pulses are transient, so that each pulse is terminated prior to reaching a steady state amplitude, while having sufficient energy to heat the TMA to its predetermined operational temperature range.

Abstract: An actuator system is provided that is configured to move a component relative to a base of the actuator system. The actuator system may include first and second actuating elements, each including two sections of material that are joined to each other and have different coefficients of thermal expansion. The two actuating elements may be configured such that if the temperature of one is increased it applies a force on the component in a direction that is opposite to the force applied by the other actuating element if its temperature is increased. The actuator system may further include at least one power supply configured to provide independently controllable heating to the first and second actuating elements.

Abstract: A miniature camera lens actuation apparatus employs an SMA actuator comprising SMA wire to move a camera lens element. To provide autofocus, the SMA actuator is heated across its range of contraction and the resistance at which the focus is at an acceptable level is stored. To combat hysteresis, there is performed a flyback in which the SMA actuator is cooled, before heating the SMA actuator to the stored resistance. The stored resistance is adjusted to combat creep caused by non-linear heating of the SMA actuator. The SMA wire has conductive material extending along on a portion of the SMA wire which extends from a member connected to the SMA wire and being in electrical connection with the SMA wire in order to short out that portion of the SMA wire to reduce creep. Additional material is applied over the SMA wire and the member to reduce fatigue.

Abstract: A resistance feedback circuit has a detecting section which detects a resistance of a shape memory alloy wire at the time of contraction and elongation, a calculating section which compares an output signal acquired from the detecting section and a signal input by a command section, and calculates an applied electric current corresponding to the resistance value detected, an output section which outputs the applied electric current which is output from the calculating section, to the shape memory alloy actuator, a control section which controls the detecting section, the calculating section and the output section, a storage section which stores a maximum value and a minimum value of the resistance which is measured in advance, and a command correcting section which corrects a signal output from the command section, based on the resistance value stored in the storage section, and a command signal which is output from the command correcting section is set to a resistance value which is higher than the minimum r

Abstract: The invention discloses a novel and efficient drive mechanism for use in a variety of applications. This novel mechanism replaces traditional stepper motors or another analogous art with shape memory alloys. The drive mechanism so disclosed provides substantial operational benefits over conventional motors and other such traditional drive mechanisms that would be used in similar applications. The drive mechanism includes a high gear-ratio worm gear and worm drive which further provides precise, controlled movement of an output shaft. In the illustrative use elaborated upon herein, the motor is used to drive a photovoltaic panel so that the panel may remain in appropriate alignment with the sun throughout the day.

Abstract: The present invention provides an actuation device having a shape memory alloy component. The present invention utilizes a length contraction occurred to the shape memory alloy component during its phase transformation from martensite to austenite. The length contraction causes a slider, a carrier and a base to move relatively. Also, the present invention utilizes thermal conductivity of the base to speed up heat dissipation of the shape memory alloy component, so that response time for actuating the carrier can be reduced.

Abstract: At the time of start of usage, a voltage to be applied to a shape memory alloy wire 102 by a feedback control circuit 120 is set to a first voltage value (step S1), and at a limit resistance value detection step, (the feedback control circuit) measures a limit resistance value when the shape memory alloy wire 102 can be contracted (step S2), and upon storing the limit resistance value, a value of the maximum voltage to be input by the feedback control circuit 120 is set to a second voltage value (step S3). At an input electric power optimization step, a target resistance value is indicated, and the feedback control is carried out such that the resistance value indicated is not lower than the limit resistance value (step S4). Thereafter, voltage is stopped at the time of stopping the use of the actuator.

Abstract: An apparatus for electrically stimulating a smart material includes a controllable power source for charging the smart material and/or switching circuitry for discharging the smart material. The controllable power source includes a regulated DC to DC converter having controllable drive circuitry associated therewith. The drive circuitry can be self-oscillating through associated feedback means. The switching circuitry can be responsive to one or more control signals.

Abstract: Heat energy is converted into mechanical energy through the mobilization of electrical charges within a thermoelectric material. A plurality of plugs of thermoelectric material are mounted on a rotor. Heat energy is directed to one end of each of the plugs. The heat energy mobilizes free charges in the plugs which collect at the relatively cooler end, thereby electrically polarizing the plugs. A pulsed electromagnetic force field acts upon the polarized plugs to exert a torque on the rotor.

Abstract: An actuator using a novel shape memory alloy which, even when there is a large difference between a transformation start temperature of the shape memory alloy and a heating start temperature, can diminish a time lag based on the temperature difference from the time when an operation start command signal is outputted until the start of movement of an actuating member, thereby causing, the actuating member to start deformation quickly and permitting a driven member to be actuated quickly. When the driven member is moved from an initial position to a reference position in operation, if the amount of movement of the driven member is larger than a normal amount of movement, an electric current larger than an electric current value calculated from the amount of movement is fed to the actuating member which is constructed of the shape memory,alloy, thereby causing the actuating member to be displaced quickly to actuate the driven member quickly.

Abstract: MEMS (Microelectromechanical System) structures are provided that are designed to rotate in response to thermal actuation or the like. In one embodiment, the MEMS rotary structure includes a hub having one or more radial spoke members that impose a rotational force upon the hub in response to applied changes in temperature. The MEMS rotary structure can also include a ring at least partially encircling the hub and connected to the hub by means of one or more hub spoke members. Controllable clockwise, counterclockwise, or both clockwise and counterclockwise rotation of the hub or ring are provided. The MEMS rotary structures can also include thermal arched beam actuators that are operably connected to the spoke member. As the temperature changes, the thermal arched beam actuators move the spoke members in order to rotate the MEMS structure.

Abstract: An actuator for selectively exerting a force responsive to an increase or decrease in applied electrical energy, including an electrically conductive member slideably seated within an electrically non-conductive frame, a thermally responsive and electrically conductive shape memorizing spring seated within the frame and adjacent to the member for urging the member responsive to the passage of electrical current through the shape memorizing spring. An electrically conductive contact strip is connected to the frame and extends therefrom in contact with the member such that movement of the member from the neutral position toward an optimal position will maintain the member in contact with the contact strip and wherein movement of the member to the optimal position will disconnect the member and the contact strip. A power source for generating energy is electrically connected to the contact strip and to the shape memorizing spring whereby a circuit is formed when the member is in contact with the contact strip.

Abstract: A pseudo-mechanical system in accordance with the invention comprises an electrical generator which converts mechanical energy into electrical energy to power the resistive heating of an ohmic electromechanical component, whose consequent form change is exploited to perform mechanical work.

Abstract: An actuation system for the control of multiple shape memory alloy elements is achieved by arranging the shape memory actuators into a matrix comprised of rows and columns which results in approximate a fifty percent reduction in the number of electrical connecting wires. This method of actuation provides the scope for resistance measurements of the shape memory alloy actuators and therefore feedback control of the actuators can be accomplished without additional wires.

Abstract: A pseudo-mechanical system in accordance with the invention comprises an electrical generator which converts mechanical energy into electrical energy to power the resistive heating of an ohmic electromechanical component, whose consequent form change is exploited to perform mechanical work.

Abstract: An apparatus and method for positioning a transducer over the center of a track is disclosed. An arm carries the transducer. Embedded in the arm is a heating element. The heating element is positioned so that the linear expansion or contraction of the arm resulting from the temperature rise or drop due to the amount of heat applied to the arm by the heating element will move the transducer across the track. In operation, a constant amount of heat is initially applied to the arm to center the transducer. During tracking, a circuit varies the amount of power applied to the heating element so that the transducer is kept over the center of the track.

Abstract: A thermal linear actuator assembly comprises, a plurality of primary linear expansion members, a plurality of secondary linear expansion members having a substantially different coefficient of expansion to that of the primary members, the primary and secondary members being alternately arranged in a side-by-side array and serially connected at opposite ends thereof, the array including first and last members each having a free end for attachment to opposite actuator attachment points whereby the thermal linear motion of the free ends in use is proportional to the total summed length of all members of the array.

Abstract: A resistance thermal unit for a thermal electric energy demand meter responsive to a variable electric quantity characterized by a dielectric housing having a pair of opposed chambers for accommodating a pair of thermal responsive bimetallic spiral springs wound on a common shaft, the springs being effective when heated to rotate the shaft in opposite directions, heating means including a heating element for each spring which element includes a flattened heat resistant dielectric core and an electric-resistant wire spirally wound on the core which wire is connected to spaced load terminals, and the assembly being disposed in a clearance space around each corresponding spring.

Abstract: A thermally controlled servo system in which a member supporting the drive for a device to be accurately positioned is moved relative to a stationary support member in response to changes in temperature of an elongated, tensioned member. Changes in temperature of the tensioned member are achieved by regulating the current flow through the tensioned member in accordance with a control signal derived from an error signal generated by the device to be positioned.

Abstract: A source of driving signals is coupled to a thermal transducer wire to provide a completed circuit. The source may include a DC bias supply and an audio amplifier. The bias supply heats the wire to a predetermined temperature, and the amplifier heats and cools the wire above and below the predetermined temperature. The wire expands and contracts in response to the audio signals, thus providing for acoustic reproduction thereof. The wire may be coupled to a diaphragm, such as a conventional speaker cone, to accomplish the acoustic reproduction. A lever arrangement coupled between the wire and the diaphragm may be employed to obtain increased diaphragm motion. A lever arrangement employing two wires in a push-pull configuration is also provided for obtaining increased motion. Additionally, a true RMS meter and a relay are provided which incorporate the heated wire thermal motion arrangement.

Abstract: An apparatus which controls the electric tracking motors of solar energy collectors and other solar devices which are adapted to be aimed at the sun.

Abstract: A wire of Nitinol can be stretched up to a given amount and will remain in this stretched state until heated to a critical temperature. When heated to the critical temperature, the wire restores to its original length. When the wire restores to its original length, it exhibits a substantial tensile force and this force can be used to operate a device such as a photographic shutter operatively attached to the wire, for example. The trigger circuit of this invention provides a current pulse for the required time period to heat the Nitinol wire to its critical temperature to thereby restore the wire to its original length. The circuit includes a high power transistor which is gated on for a controlled time to provide the required power to heat the Nitinol wire to its critical temperature.