Miniature Joule-Thomson Rankine-Cycle Refrigerators

Miniature, lightweight, low-power, low-vibration Joule-Thomson Rankine-Cycle refrigerators have been proposed for cooling portable scientific instruments. These refrigerators would be made largely from silicon wafers by micromachining techniques like those used to fabricate integrated circuits. The compressors in these refrigerators would be microperistaltic pumps, in which voltages applied in spatial and temporal sequences to multiple electrodes positioned along channels would give rise to waves of electrostatic attraction that would cause membranes to pinch the channels closed at intervals in peristalsislike waves. [A fuller description of microperistaltic pumps was presented in "Microscopic Heat Exchangers, Valves, Pumps, and Flowmeters" (NPO-19093), NASA Tech Briefs, Vol. 22, No. 7 (July 1998), page 66.]