Some engineers are trained in the art of building things out of folding sheets of paper and metal into useful objects (origami). One design that came from this training was a solar panel that folds up for transport and then unfolds once it is in orbit. Now, two engineers from the http://rspa.royalsocietypublishing.org have developed an origami-based method of making a collapsible grocery bag. It is loosely based on a five-year-old design from a mathematician from the Massachusetts Institute of Technology. That design’s major flaw was that it needed a material with zero thickness. The new design, on the other hand, starts with a large piece of plastic with steel plates glued to it. Folds and creases are made where the steel plates meet. Thus, the flexible plastic holds the bag together despite being folded. The bag collapses down to a relatively thin, flat sheet. No word yet on how much the bag weighs or if designers plan on adding handles.
More details are available on Proceedings of the Royal Society A.