This is lowpoly version of GYROID surface. The gyroid is an infinitely connected triply periodic minimal surface discovered by Alan Schoen in 1970. The gyroid separates space into two oppositely congruent labyrinths of passages. Channels run through the gyroid labyrinths in the (100) and (111) directions. The model consists of 2x2x2 basic elements of Gyroid and can be patterned even more.
3D printing? Check out my thickened lowpoly Gyroid sample adapted for 3D printing (GYROID lowpoly - 3D printable sample)