"This is when I knew we had something," says Sarjoun Skaff, as a video plays on his laptop, showing a robot he helped design, RHex , ambling across the quad at Carnegie Mellon. Preschoolers happened to be around during the filming--and they were going insane. They run up to it and run away and squeal. They hide and stare. They scream some more. One kid actually grabs his crotch, as if he's going to wet his pants. And no wonder: The robot's six legs propell it  in a dopey shuffle, like an old bulldog that Robocop might own.
Skaff had always been interested in making toy robots. "It's the best way to introduce robotics to the public," he says. "And toys allow you unlimited creativity." RHex, however, wasn't a toy. It was a $20,000 robot funded by the DARPA, the Defense Department's mad-science program. Retrofitting the tech and making it cheaper took four years. And this fall, RHex will finally be reincarnated in two toys, available this fall, dubbed Prime-8 ($99.99) and Penbo ($79.99).
So what made the transformation possible? Although Skaff and the co-founders of Bossa Nova Robotics had the basic locomotion principal, the robot had to do more. But what? "We talked to product experts and consulted books about how kids play," Skaff explains. A toy for boys had to involve three core "play patterns": Power, Mastery, and Competition. So they designed the Prime-8 to move fast and shoot rockets; to be controlled by an X-Box--like controller complicated enough that it would require kids to become experts; and they designed it with IR sensors, so that robots could play laser tag with each other and race. Triggered by loud noises, it can become angry or happy, stomping around or break-dancing. It can be programmed as a guard, to shoot intruders.
Meanwhile, the key to a toy for girls is nurturing. So the Penbo has a baby inside it. Sensors allow it to respond to petting. It's actually controlled by buttons embedded in the wings of the baby; when reunited, the mom rocks the baby to sleep. "You're taking care of the mom," says Skaff. "And you're helping the mom take care of the baby." The robot also plays hide and seek, tag, and peek-a-boo, using motion detectors.
Skaff says that Bossa Nova's biggest goal isn't mere fun. "A big part of robots is that they can interest kids in science and technology," he says. "In the manuals, we use technical terms and explanations. So that maybe technology becomes cool, and maybe you'll pursue science when you grow up."