LIGA-Fabricated High-Performance Micro-Channel Regenerators for Cryocoolers

The LIGA micromachining process can be used to fabricate sheets perforated with micro channels having length/diameter (L/D) ratios between 10 and 20. The potential benefit of a regenerator composed of an aligned stack of these sheets and fabricated from a material with good cryogenic thermal properties is quantified via analytical as well as numerical models. A cross flow micro heat exchanger is described using a derivative of the LIGA process that has excellent heat transfer/volume performance. Modifying the process sequence to make these heat exchangers could potentially produce cryocooler regenerators with excellent performance.