University of California - Berkeley

Leaping lizards and dinosaurs inspire robot design

University of California, Berkeley, biologists and engineers including undergraduate and graduate students studied how lizards manage to leap successfully even when they slip and stumble, and found that swinging the tail upward is the key to preventing a forward pitch that could send them head-over-heels into a tree.

The scientists subsequently added a tail to a robotic car they named Tailbot and discovered that it's not as simple as throwing your tail in the air. Robots and lizards have to adjust the angle of their tail just right to counteract the effect of the stumble. Given an actively controlled tail, even robots can make a leap and remain upright.

"We showed for the first time that lizards swing their tail up or down to counteract the rotation of their body, keeping them stable," said team leader Robert J. Full, UC Berkeley professor of integrative biology. "Inspiration from lizard tails will likely lead to far more agile search-and-rescue robots, as well as ones having greater capability to more rapidly detect chemical, biological or nuclear hazards."

Agile therapod dinosaurs like the velociraptor depicted in the movie Jurassic Park may also have used their tails as stabilizers to prevent forward pitch, Full said. Their tail movement is illustrated in a prescient sequence from the 1993 movie in which the animated animal leaps from a balcony onto a T. rex skeleton while chasing the lead characters....