Abstract: A rotary actuator (100) having a reference structure (110), an output member (113) arranged for rotary movement relative to the reference structure, a first linear motor (116) arranged to selectively apply an output force urging a first motor member (119) and a second motor member (122) apart along a generally linear direction, in which the first linear motor is configured and arranged to cause a torque between the output member and the reference structure in a first direction, and second linear motor (137) arranged to selectively apply an output force urging a second linear motor first member (134) and a second motor member (137) apart along a generally linear direction, in which the second linear motor is configured and arranged to cause a torque between the output member and the reference structure in a direction opposite to the first direction.