Wednesday, September 08, 2010

self-folding origami

Origami Sheets That Fold Themselves
By John Matson

Researchers have invented a real-life Transformer, a device that can fold itself into two shapes on command. The system is hardly ready to do battle with the Decepticons—the tiny contraption forms only relatively crude boat and airplane shapes—but the concept could one day produce chameleonlike objects that shift between any number of practical shapes at will.

Self-folding sheets are just one facet of programmable matter. “Instead of programming bits and bytes, you program mechanical properties of the object,” says Daniela Rus, a roboticist at the Massachusetts Institute of Technology.

The system, described online June 28 in the Proceedings of the National Academy of Sciences USA, consists of a thin sheet of resin–fiberglass composite, just a few centimeters across, segmented into 32 triangular panels separated by flexible silicone joints. Some of the joints have heat-sensitive actuators that bend 180 degrees when warmed by an electric current, folding the sheet over at that joint. Depending on the program used, the sheet will conduct a series of folds to yield the boat or airplane shape in about 15 seconds.

The researchers say that in principle the system could produce many more shapes than two. “We were looking for ways to embed a bunch of different functionalities into one low-profile sheet,” says co-author Robert J. Wood, an electrical engineer at Harvard University.

In the near term, Rus envisions the computational origami technology forming the basis of three-dimensional displays—for instance, maps that can reproduce the topography of a given region on demand. In the more distant future, applications might move beyond shape mimicry to involve programmable optical, electric or acoustic properties.