A heat recuperator includes a plurality of channel walls composed substantially of thermally-conductive material and supported in spaced-apart relation, defining fluid channels and interstices therebetween. The fluid channels receive at least one primary fluid flow and the interstices receive at least one secondary fluid flow so as to effect heat exchange between the two flows. In use, the plurality of channel walls are deformable by pressure differential between the primary and secondary fluid flows. When at least some of the channel walls are in a deformed state, the plurality of channel walls are stabilized through press fit engagement of mutually opposed contact regions formed in adjacent pairs of the channel walls.