Patent ID: 8904780

Claim:
A temperature-driven mechanical system comprising: a first effector, made of temperature-induced shape-changing material, having first and second ends and a longitudinal axis running through at least one of the ends; a suspension system that mounts an assembly including the first effector, to support rotation of the assembly about the longitudinal axis; the suspension system having first and second rotation limit stops to limit rotation of the assembly to less than 180 degrees about the longitudinal axis, wherein the first rotational limit stop is associated with a first angular position of the assembly at or below a first temperature limit and the second rotational limit stop is associated with a second angular position of the assembly at or above a second temperature limit; wherein the suspension system is configured so that at the first temperature limit the first effector assumes a first shape that causes the center of gravity of the assembly to be located on a first side of a vertical plane passing through the longitudinal axis and at the second temperature limit the first effector assumes a second shape that causes the center of gravity of the assembly to be located on a second side of the vertical plane, so that a temperature-induced change in shape of the first effector harnesses gravity to cause motion of the first effector between the first and second rotation limit stops.