Sonobes: Cornerstone of Modular Origami

Although battling a severe bout of sickness, I thought I’d post some more informative material regarding the history and mathematics of modular origami.  And seeing how many of my models are created using Sonobe modules or derivatives thereof, it felt a natural place to begin the discussion.

According to origami lore, the Sonobe module was created by its namesake, Mitsunobu Sonobe, in the early half of twentieth century Japan.  These parallelogram modules feature folds at 45 and 135 degrees, with two built-in pockets.  Thanks to the tab-pocket system, shapes can be assembled and held together entirely without the aid of adhesive.  It is due to this strength, along with the plenitude of shapes this modules can create, which has added to its longevity.

The simplest of Sonobe shapes, known as Toshie’s Jewel, is made with only 3 modules.  Cube constructions can be assembled using 6 or 12 unit assembly methods, as can 12 unit octahedral assemblies.  One of the most well-known shapes, and a personal favorite, is the icosahedron, which is comprised of twelve pentagonal faces and requires 30 units to assemble.  Of course, other larger polyhedra are equally viable, including spiked pentakis dodecahedron, and the large 270 module “buckyball.”

Adding further to this design’s endurance is the virtually endless ways in which this module has been modified over the decades.  Through the small adjustments of folds, brilliant color contrasts and shape differentiations are created.  In fact, you’d be hard pressed to find a modular origami unit which does not in some way draw inspiration from the original Sonobe.  So thank you for this ingenious fold, which opened the gateway for a whole genre of origami!