Relatively large strokes are produced at temperatures between 30 and 60 K.
Electrostrictive ceramic actuators that can function at low temperatures have been developed for controlling the shapes of mirrors in the Next Generation Space Telescope (NGST). On Earth, electrostrictive ceramic actuators may be useful for fine control of the positions of objects in cryogenic laboratory apparatuses and in industrial cryogenic (including superconducting) systems.
On the basis of a number of candidate electroceramic materials, one material was found to be capable of a relatively large stroke in the temperature range of 60 K, such as to satisfy the specific stroke requirement for the NGST. Deformable mirrors that included actuators made from this material were assembled, using cutting and bonding techniques to form the material into actuators of the required sizes and shapes.
This work was done by Maureen L. Mulvihill and Mark A. Ealey of Xinetics, Inc., for Marshall Space Flight Center. For further information, access the Technical Support Package (TSP) free on-line at www.techbriefs.com/tsp under the Materials category.