CRYOCOOLER REGENERATOR CONTAINING ONE OR MORE CARBON-BASED ANISOTROPIC THERMAL LAYERS

An apparatus includes a regenerator configured to transfer heat to a fluid and to absorb heat from the fluid as the fluid flows between a warm end and a cold end of a cryocooler. The regenerator includes an anisotropic thermal layer configured to reduce a flow of heat axially along the regenerator and to spread the absorbed heat radially or laterally in a plane of the anisotropic thermal layer. The anisotropic thermal layer includes at least one allotropic form of carbon. The anisotropic thermal layer could have a higher radial or lateral thermal conductivity and a lower axial thermal conductivity. The anisotropic thermal layer could include carbon nanotubes and/or graphene. The regenerator could include multiple anisotropic thermal layers that divide the regenerator into multiple segments, where the anisotropic thermal layers are configured to reduce heat transfer between adjacent segments of the regenerator.