Engineers at the University of Colorado Boulder have developed a new rubber-like film that could pose strong competition to grasshoppers.
This new material can jump on its own, without any outside intervention, you just need to heat it. Scientists foresee such materials could one day help embody “soft robots” to leap or lift.
“In nature, a lot of adaptations like a grasshopper’s leg utilize stored energy, such as an elastic instability,” CU Boulder Gallogly Professor Tim White said in a statement. “We’re trying to create synthetic materials that emulate those natural properties.”
Tayler Hebner, the study lead author, said, “This presents opportunities for using polymer materials in new ways for applications like soft robotics where we often need access to these high-speed, high-force actuation mechanisms,”
It was not a planned design; researchers accidentally discovered this material.
The science behind the leaping behavior of that film
Each of the films was about the contact lens size and consisted of three layers of elastomer. When heated, the top two layers shrink faster than the bottom layer. As a result, it forms a cone shape. With the formation of a cone shape, strain builds up in the film. Consequently, the cone inverts, slapping the surface and snapping up into the air.
“As those films heated up, they began to warp, forming a cone that rose until, suddenly and explosively, it flipped inside out—shooting the material up to a height of nearly 200 times its thickness in just six milliseconds,” according to the release.
“We were just watching the liquid crystal elastomer sit on the hot plate wondering why it wasn’t making the shape we expected. It suddenly jumped right off the testing stage onto the countertop.” Hebner said. “We both just looked at each other kind of confused but also excited.”