1987 Lakes Metamaterial (20mm cells)

I saw in article in [u]Science[/u] (24 Nov 2017, pp. 994 & 1072) about an interesting type of metamaterial, one with a structure that shrinks laterally instead of growing as compression is applied to it.  This model was originally developed by R. Lakes in 1987 and finally revisited 30 years later by T. Frenzel, et al in nanoscale lattices.  I thought it was pretty cool, so I decided to upload a model of it. Currently, I'm offering this design in three sizes.  The extra small model is a single cell, the medium model is 3x3x3, and the extra large model is 5x5x5.  I sincerely hope that I actually got the array right, otherwise this lattice will not work as Lakes intended it.  Fingers crossed!