Infinite Periodic Discrete Minimal Surfaces Without Self-Intersections
  A triangulated piecewise-linear minimal surface in Euclidean 3-space defined using a variational characterization is critical for area amongst all continuous piecewise-linear variations with compact support that preserve the simplicial structure. We explicitly construct examples of such surfaces that are embedded and are periodic in three independent directions of Euclidean 3-space. 
Wayne Rossman