University of Washington

Hsiu-hung Chen

Minoru Taya

Taishi Wada

Masahiro Kusaka

Victor Cheng

Chiyuan Wang

Multiple embodiments of ferromagnetic shape memory alloy (FSMA) based torque actuators are described. These torque actuators include a magnetic trigger and an FSMA member, which when actuated by the magnetic trigger, produces a torque for rotating a member. Examples of magnetic triggers include hybrid magnetic triggers having at least one electromagnet and at least one permanent magnet. The FSMA member can be configured as a coil (or plate) spring and can be fabricated of a true FSMA alloy (i.e., an alloy that exhibits both ferromagnetic and shape memory properties) or of an FSMA composite that includes a ferromagnetic portion and an SMA portion. Several embodiments include a central orifice in which the FSMA member and an axial rod configured to rotate when actuated are disposed; the magnetic trigger system is disposed about the periphery of the orifice.

Torque actuator incorporating shape memory alloy composites

The present invention employs an optimized cross-sectional shape for a ferromagnetic shape memory alloy (FSMA) composite that is used in a spring-type actuator, an improved hybrid magnetic trigger for use in FSMA based actuators, an a FSMA composite based spring type actuator, an a FSMA based spring type actuator including a stack of triggering units and FSMA springs, a FSMA composite based torque actuator. The invention also includes a model that can be employed to evaluate different materials being considered as components a FSMA for a FSMA composite used in either a FSMA based torque actuator or a FSMA spring actuator.

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Seattle, WA, United States of America

Hsiu-hung Chen