Kirigami adds cuts to the folding vocabulary of origami. Instead of asking a solid sheet to stretch, the pattern lets rigid islands rotate around narrow hinges. The material changes shape because geometry moves, not because the paper itself becomes elastic.
This sketch uses a rotating-square lattice. Each panel is drawn as a nearly rigid unit, while the bright slits mark the cut lines that separate neighboring panels. Opening the sheet rotates alternating squares in opposite directions, creating pores between them. Pointer movement locally increases the opening, like pulling on one patch of the sheet.
The important behavior is auxetic. Many materials get narrower when stretched. Rotating-square kirigami can do the opposite: pull it in one direction and it expands sideways too, giving an effective negative Poisson ratio. The layout, hinge stiffness, and cut length determine how much motion the sheet can absorb before the material itself has to strain.
Engineers use these ideas as mechanical metamaterials: structures whose bulk behavior comes from pattern and mechanism rather than chemistry alone. Small changes in the cuts can tune stretch, porosity, bending, and snap-through behavior. Here the model is intentionally kinematic, so the visual emphasizes the motion of the mechanism over stress or fracture.
Wikipedia: Kirigami · Auxetic mechanical metamaterials