MEMS Flow Controller for Cryocoolers

There is a strong interest in pulse tube cryocoolers for strategic and tactical applications. The pulse tube cryocooler derives its thermodynamic performance from a controlled movement of a gas volume within a tube resulting in extraction of heat from a definable cold interface. Performance of pulse tube cryocoolers is strongly dependent upon accurate control of the gas flow to achieve a matching of the moving gas volume with the tube volume and effective phasing of the gas volume motion relative to driving pressure waveforms. TAI will incorporate a MEMS-based valve array to accurately and remotely control the gas flow. A major benefit of this controllable micro-miniature flow manifold is dynamic flow management with minimal addition of parasitic void volume to provide enhanced cryocooler performance. The proposed approach to package multiple electrostatic flow control valves in a configuration that satisfies the cryocooler application requirements was developed in Phase I and study results revealed that significant gains in pulse tube cryocooler performance can be realized. In Phase II, a prototype flow control device will be fabricated and integrated with a dedicated pulse tube cryocooler test bed to demonstrate the proposed embodiment.