NASA 1998 SBIR Phase I


PROPOSAL NUMBER: 98-1 14.01-7485

PROJECT TITLE: Single Crystal Piezoelectrics For Cryogenic Actuators

TECHNICAL ABSTRACT (LIMIT 200 WORDS)

Single crystal piezoelectrics having strains > 1% (an order of magnitude greater than conventional ceramics) are proposed as the electroactive material for adaptive optics on the Next Generation Space Telescope (NGST). These single crystals have piezoelectric coefficients at 20 K (the NGST operation temperature) equivalent to those of Type VI PZT at room temperature. Compositional adjustments are proposed to further enhance crystal performance at cryogenic temperatures; a similar methodology was successfully demonstrated at TRS for improving the cryogenic performance of PZT ceramics. Measurements will determine if the electric field induced phase transition, which results in large strains at room temperature, still exists at cryogenic temperatures. Based on cryogenic strain and thermal expansion measurements, design rules will be developed for single crystal multilayer actuators that operate from room temperature to below 20 K. Crystal stack actuators fabricated in this program can serve as the active component in a number of actuator designs being considered for the NGST. TRS Ceramics, Inc. has an exclusive license from The Pennsylvania State University for the use of single crystals in actuator applications. As a producer of specialty piezoelectrics, TRS is in an ideal position to develop actuators for the still developing cryogenic market.

POTENTIAL COMMERCIAL APPLICATIONS

Cryogenic actuator applications are currently as active elements in inchworm motors, resonant screw drives, and flextensional positioners used in the adaptive optics of space-based telescopes such as NGST. Other potential applications include vibration or flap control on high altitude aircraft, flow control of cryogenic fluids, and vibration sensors for cryogenic environments. Fabrication techniques developed in this program will also be used in a broad variety of applications that utilize the high room temperature strain levels of these crystals.

NAME AND ADDRESS OF PRINCIPAL INVESTIGATOR

Dr. Wesley Hackenberger
TRS Ceramics, Inc.
Suite J, 2820 E. College Ave.
State College , PA 16801-7548

NAME AND ADDRESS OF OFFEROR

TRS Ceramics, Inc.
Suite J, 2820 E. College Ave.
State College , PA 16801-7548