Shape memory alloy based linear actuator assembly

摘要

A linear motion device includes a rod extending along a longitudinal axis, and a plurality of actuator units. Each of the plurality of actuator units includes at least one Shape Memory Alloy (SMA) element that is attached to a coupling mechanism. The at least one SMA element of each if the plurality of actuator units moves the coupling mechanism along the longitudinal axis, and into grasping engagement with the rod. Each actuator unit moves the rod a unit movement distance along the longitudinal axis in response to a control signal. The plurality of actuator units are actuated repeatedly in a cyclic order to move the rod in a continuous linear motion a distance greater than the unit movement distance of each of the plurality of actuator units.

主权项

1. A linear motion device comprising:
a rod extending along a longitudinal axis; and a plurality of actuator units, with each of the plurality of actuator units including at least one Shape Memory Alloy (SMA) element attached to a coupler, wherein the at least one SMA element of each of the plurality of actuator units moves the coupler along the longitudinal axis and into grasping engagement with the rod to move the rod a unit movement distance along the longitudinal axis in response to a control signal; wherein the plurality of actuator units are actuated repeatedly in a synchronous order to move the rod in a continuous linear motion a distance greater than the unit movement distance of each of the plurality of actuator units; wherein each of the plurality of actuator units includes a first coupler and a second coupler disposed on opposite sides of the rod; and wherein the at least one SMA element includes a connecting SMA element extending between and attached to both the first coupler and the second coupler and configured to contract to draw the first coupler and the second coupler together into grasping engagement with the rod in response to the signal.