Magnetostrictive force actuators for superprecise positioning

Magnetostrictive actuators for superprecision positioning in steps of 10(-2) nm over a range of displacements up to 1m have been developed and investigated. The actuators generate forces up to 10(4) N and are suitable as force actuators in steps of 10 nm. Exact displacement is achieved by an active element made from Terfenol D alloy based on rare-earth metals with a giant magnetostriction. The actuators can be controlled manually without any additional power source or by using a computer. For manual control the minimum linear-displacement step does not exceed 3 nm, and when the device is used on a turntable the minimum angular displacement step is 15-10(-3) angular seconds, while for computer control these quantities are 10(-2) nm and 4.10(-5) angular seconds respectively.