Project Title:
Diaphragm Actuator for a Stirling Micro-Refrigerator
09.07-2221
911140
Diaphragm Actuator for a Stirling Micro-Refrigerator
Sunpower, Inc.
6 Byard Street
Athens
OH
45701
Lyn
Bowman
614-594-2221
GSFC
NAS5-31940
189
09.07-2221
911140
Abstract:
Diaphragm Actuator for a Stirling Micro-Refrigerator
The innovative compressor for this closed cycle cryogenic cooling system is a silicon
diaphragm actuator. This project addresses development of a compressor for a novel
Stirling micro-refrigerator for cold electronics. The micro-refrigerator concept
exploits the material properties, mechanical designs, tiny dimensions, and batch
fabrication processes of silicon micro-machining technology. One preliminary design
of a micro-refrigeration with a volume of one cubic centimeter predicts 0.73 W of
heat lifting capacity from 100 K to 350 K with a mechanical input power of 3.2 W
at 1 kHz. The inertial of the vibrating actuator is only 10-4g. A critical component
of the micro-refrigerator is this electromechanical actuator that drives the Stirling
cycle. This project combines the high-Q mechanical properties of resonant silicon
microstructures, the actuators of silicon micro-valves, and the ability of corrugated
diaphragms to undergo large deflections to compress, displace, and expand the working
fluid in the micro-refrigerator. Phase I will design a corrugated, silicon diaphragm
actuator, capable of undergoing the required deflection, and will evaluate the capability
of alternative electromechanical transduction techniques for exciting vibrations
in the diaphragm. In Phase II, diaphragms will be fabricated and tested. These low-vibration,
electrically powered micro-refrigerators would be ideal for providing tight closed-loop
cryogenic temperature control for instruments and facilities at dispersed locations
in future unmanned spacecraft.
The commercialization of Stirling micro-refrigerators would increase the speed of
computer processors and memories; reduce noise in radio and microwave detectors,
amplifiers, and filters; reduce the bulk of infrared detection and imaging systems;
and facilitate the commercialization of high-Tc superconducting electronics.
compressor, cooling, Stirling, micro-machining, silicon