How hard can it be to make a lizard run? Just ask the researchers in Daniel Goldman’s laboratory at Georgia Tech. ”It’s very high tech,” says Goldman [left]. ”We startle it.”
They wave bits of cardboard, flash lights, and gently pinch the lizards’ tails. Then they do it again. And again. And again. ”Sometimes I try to make a noise, but that doesn’t seem to work,” says Chen Li, a physics graduate student [right].
The 65 lizards, crabs, and cockroaches in Goldman’s lab can be ornery companions to the one robot that beats a steady path down a track in the lab. In ”March of the SandBots,” Goldman and his colleagues explain how they invested in that robot the tricks they’d learned about sand scampering from the finest desert runners on the planet.
But building a bio-inspired robot can involve a few odd negotiations. To acquire some of the creatures in Goldman’s menagerie, one student coaxed collectors in the Middle East into selling their prized Egyptian desert cockroaches ( Polyphaga aegyptiaca ) for about US $10 a bug.
Goldman, too, contributes a catch or two. He grew up chasing ghost crabs on the sandbar islands of North Carolina and five-lined skinks around his home in Richmond, Va. At the age of 10 he learned how to snag one of those lizards: He’d dangle a coil of rope on a pole and stand several steps from his target. Then he’d lower the noose around its neck and pull up, ensnaring the thrashing skink and delivering it unharmed to a cloth bag.
But unlike lizards in the wild, captive animals can be exhaustingly placid. ”I can say, ’Animal, go!’ or ’Animal, move your legs in a certain way,’ and it won’t do that,” Goldman reports. Indeed, an annoyed ghost crab may instead go on the offensive, snapping its claws energetically at its appointed frightener.
Li, who grew up watching animal documentaries in China, hadn’t anticipated how unpredictable the animals would be. So when it’s the robot’s turn to strut, the physicists breathe a sigh of relief. ”The robot gives us data that’s more repeatable,” Li says. ”It’s very nice.”