This is one of our earlier experiments in printing soft microstructures. It is a 12x12x12 tiling of 10-3-a pattern. Each cell is of size 2.5mm, and each rod is ~0.25mm thick.
Special thanks to Prof. George Hart for explaining this pattern through email. Please see more 10-3-a pattern at here.
Download 3D model: http://www.thingiverse.com/thing:835501