Oribotics - the art/science of robotic origami

Rigid Origami

June 20, 2005 on 11:15 pm | In Oribotics |

Tom Hull, a US based mathematician and origami researcher, has written a number of articles about the subject of Rigid Origami. Rigid origami is essentially a crease pattern in which:

(1) Paper does not stretch.
(2) The faces of the folded paper are flat (as opposed to curved).
(3) We do not want the paper to rip or have holes.
(4) Paper does not intersect itself.

See: http://www.merrimack.edu/~thull/rigid/rigid.html

If a crease pattern meets these criteria (its a bit more complex than this), but points 1 and 2, are essential in understanding a rigid fold.

The results of which are a crease pattern which is ideal for oribotics. Oribotics requires a crease pattern which can be set into motion with a mechanism. The first oribotic flowers are not rigid folds, however the amount which the crease pattern requires the faces to curve is small enough to allow the flower to open and close. But the springiness of the flower, is a result of the tension from the paper (or plastic) curving. If this were eliminated by altering the crease pattern the tension would be removed and the folding would require less energy.

Note that the first prototype oribot was based on a square twist fold crease pattern, however the twist was symmetrical, unlike this animation shown here: http://www.merrimack.edu/~thull/rigid/squaretwist.mov