Oscillating diaphragms

The manufacture of miniature Stirling cycle cryocoolers, using standard micro-machining techniques and materials has been pursued by the authors [1]. A MEMS based cryocooler would allow integration of a cryogenic cooling system directly into a cryo-electronic device. Resonant bossed diaphragms were proposed as the means to sweep the working gas in the Stirling cooler, replacing the pistons and displacers found in macro scale free-piston machines. Analysis of round, bossed diaphragms led to the realization that there exists shape factors by which the swept volume and kinetic energy of any diaphragm can be characterized. Knowledge of the volume swept by a diaphragm allows for the calculation of a potential energy associated with diaphragm deflection. Knowledge of the potential and kinetic energies allows for the design of a diaphragm of known dynamic characteristics operating in a closed gas space with large gas pressure spring and damping effects.