I working on something similar to a laminar flow gate , just very thin relative to the size of the part (~6 in x 12in x 0.2 in). The interior mesh walls are also very thin ~0.010". I'm looking for an optimal lattice structure that could give the best structural integrity, especially against twisting/shearing. Lattice size and shape (square, triangle, hexagon, etc.) are flexible. I also think a mesh of equilateral triangles would be optimal, but am curious if there is anything to back this up.
Unfortunately, I can't use any cool two layer structures. It's got to have straight through-passages.