University of Washington

Victor Cheng

Minoru Taya

Taishi Wada

Yuanchang Liang

Masahiro Kusaka

Hsiu-hung Chen

Hsiuhung Chen

Chi-Yuan Wang

Chiyuan Wang

Harry Sugandi

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

Linear actuators (also known as an inchworm actuator) including a magnetically actuatable shape memory alloy (SMA) are described. The linear actuators include a bar and an actuator assembly, configured to achieve a linear displacement of the actuator assembly relative to the bar. A hybrid magnetic trigger including an electromagnet and a permanent magnet is used to selectively attract the magnetically actuatable SMA toward the magnetic trigger. The motion of the magnetically actuatable SMA can be converted to a linear displacement. The magnetically actuatable SMA can be implemented using a SMA exhibiting both ferromagnetic and SMA properties, or by a ferromagnetic mass coupled with an SMA (i.e., a ferromagnetic SMA composite). Linear actuators including bars incorporating a ratchet mechanism, and featureless bars are described. A hydraulic system incorporating actuators including magnetically actuatable SMA membranes is also disclosed.

Actuators based on ferromagnetic shape memory alloy composites

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Chandler, AZ, United States of America

Victor Cheng