Thermal regenerator apparatus

A method for fabricating a thermal regenerator medium having a plurality of flow passages extending between first and second ports, the flow passages facilitating back and forth fluid flow in a generally transverse direction while the medium alternatively receives thermal energy from and delivers thermal energy to the fluid, the method comprising:

• providing first and second foils, each foil having a plurality of channels extending through the foil and having beveled sidewalls, the channels having a width and spacing in the transverse direction, the first foil having a first foil pattern including channels disposed at a first offset with respect to a first longitudinal reference on the foil and the second foil having a second foil pattern having channels disposed at a second offset with respect to a second longitudinal reference on the foil, the channels being elongated in a longitudinal direction orthogonal to the transverse direction and being divided by foil bridges extending transversely and sized to reduce thermal conduction through the medium in the transverse direction;
• aligning the first and second longitudinal references of the respective first and second foils such that the channels of the first foil are transversely offset to span between and be in fluid communication with the channels of the second foil;
• and
• winding first and second foils around a cylindrical spool to produce a generally cylindrical shaped regenerator medium.