Thin polymer discs self-propel by repeated "snapping" motions. Credit: Yongjin Kim, UMass Amherst
Topics: Chemistry, Polymer Science, Materials Science, Research
A polymer-based gel made by researchers in the US and inspired by the Venus flytrap plant can snap, jump and “reset” itself autonomously. The new self-propelled material might have applications in micron-sized robots and other devices that operate without batteries or motors.
“Many plants and animals, especially small ones, use special parts that act like springs and latches to help them move really fast, much faster than animals with muscles alone,” explains team leader Alfred Crosby, a professor of polymer science and engineering in the College of Natural Sciences at UMass Amherst. “The Venus flytraps are good examples of this kind of movement, as are grasshoppers and trap-jaw ants in the animal world.”
The Venus flytrap plant works by regulating the way its turgor pressure – that is, the swelling produced as stored water pushes against a plant cell wall – is distributed through its leaves. Beyond a certain point, this swelling leads to a condition known as snapping instability, where the tiny additional pressure of a fly’s footsteps is enough to cause the plant to snap shut. The plant then automatically regenerates its internal structures in readiness for its next meal.
Polymer gels snap and jump on their own, Isabelle Dumé, Physics World