Earwigs can fly but they mostly live underground, intricately folding their wings into a surface area that's 10 times smaller than when they're opened up. According to new research, the folds "cannot be sufficiently described by current origami models." The earwigs manage the marvelous by incorporating a bit of stretch into the joints where the creases occur, leading to a new design for a robotic gripper. From Science News:
(The earwig's wings are) an example of a bistable structure — something like the slap bracelets, popular in the 1980s and 1990s, which switch from a flat conformation to a curved one when whacked against a wrist, says study coauthor André Studart, a materials scientist at ETH Zürich. When locked open, earwig wings store energy in the springy resilin joints. When that strain is released, the wings rapidly crumple back to their folded position.
Such constructions can inform robotics design. Inspired by the wings, the researchers created a prototype gripper. Its rigid pieces are held together by rubbery, strategically placed joints. Within fractions of a second, the structure can snap from its mostly flat conformation to one that can grip a small object and hold it without constant external force.