Peacock butterfly

Paper-thin origami-like artworks wriggle, flutter and bend

Image credit: Dreamstime

Designers and engineers from the University of Colorado-Boulder have developed shape-changing objects which are paper-thin, fast-moving and almost silent. Among other applications, they suggest that the objects could be used to enhance pop-up books to include moving paper creatures.

Their early creations, which they call Electriflow, include origami cranes with bending necks, wriggling flower petals and fluttering butterflies.

“Usually books about butterflies are static,” said Purnendu, a graduate student. “But could you have a butterfly flap its wings within a book? We’ve shown that it’s possible.”

Origami butterfly flaps wings

Origami-inspired butterly/Pernendu

Image credit: Purnendu

Purnendu explained that Electriflow designs don't require motors or other traditional machine parts to come to life, allowing them to be soft to the touch. Instead, they use a type of artificial muscle developed at the university which has since been commercialised by Artimus Robotics. These artificial muscles harness hydraulically amplified self-healing electrostatic actuation; they rely on electrostatic forces to push oil between sealed pouches, causing a change in change. The developers of the technology compare it to how the shape of a ketchup sachet changes when one side is squeezed.

“One of the main benefits of these actuators is that they’re versatile,” said Eric Acome, CTO at Artimus Robotics and co-author of the new study. “They’re just pouches, but depending on the shape of that pouch, you can generate different kinds of movement.”

Purnendu and his collaborators were interested in the connection between this technology and shapeshifting in the natural world, such as the inflation of a pufferfish or closing motion of a Venus fly trap: “Shape changing is a big part of communication and survival for certain animals. Engineers have been on a quest to develop similar kinds of functions for computer interfaces,” he explained.

They wondered if they could use this approach to actuation to design soft, moveable artwork, which is how Electriflow began. Electriflow takes advantage of several different pouch shapes to create origami-like folds in flat plastic sheets.

The result is a paper-thin object, which can move extremely quickly; Purnendu’s Electriflow insects can beat their wings up to 25 times per second, which is faster than most butterflies and comparable to fast moths.

“This system is very close to what we see in nature,” he said. “We’re pushing the boundaries of how humans and machines can interact.”

He hopes that artists and designers will use the tools he and his colleagues have developed to push those boundaries further and play with different geometries. He images that eventually it may be possible to create origami animals, which fold themselves into different animal shapes from a flat sheet of paper or plastic and run and jump in the pages of a book.

Sign up to the E&T News e-mail to get great stories like this delivered to your inbox every day.

Recent articles