In Holly Yanco's office, robots of every sort--windup, stuffed, and model, ranging from C-3PO to Bender--vie for space with the hundreds of brightly colored Pez dispensers that line the three crowded shelves, the counters, and the top of the whiteboard.

Nestled among the toys is a small, worn wheel, slightly larger than a doughnut. Yanco, who directs the robotics lab at the University of Massachusetts, Lowell, holds it up. "This is the end of my thesis," she says with a chuckle. As a doctoral candidate at MIT in the late 1990s, Yanco developed a robotic wheelchair she called "Wheelesley." (She'd started working on it as a visiting lecturer at Wellesley, her alma mater.) Wheelesley's stereo vision system and distance sensors allow it to automatically identify and navigate around obstacles such as poles and steep drop-offs like curbs or stairs."I was testing the robot over by Building 34, and the castor just cracked," she recalls. "This was about a week before my defense." A fellow grad student helped her push the wheelchair back across campus, and she found a vendor to overnight a replacement part. She keeps the cracked wheel on the shelf to remind her students that technical difficulties encountered by doctoral candidates--and obstacles faced by people with mobility issues--are part of life. But it's also a reminder that such problems can be overcome.

Yanco's no-nonsense approach has served her well in her effort to develop both robotic aids for people with disabilities and remote-controlled robots that can help do such things as look for disaster survivors. Both kinds of robots, Yanco says, require intuitive user controls, sophisticated sensors, and intelligent mapping capabilities. And to increase the chances that such robots will be truly useful outside the lab, she thinks carefully about finding the right balance between human control and robot autonomy.

"When you're driving down the street, there are a lot of things you do with small corrections that you don't even think about," she explains. "You're thinking about the higher level--do I need to turn at the next intersection. But when you have someone in a wheelchair who has trouble with fine motor control, all of the really tiny controls are just as much effort as the large controls. If you can ... just have them think about the larger stuff, it can make it easier for them to drive the chair." For example, Yanco says, a wheelchair user who wants to go to a room on the third floor of a hotel should need only to say the room number, and the robot should be able to manage each smaller step: going from the lobby to the elevator, pushing the elevator button, entering the elevator, pushing the floor button, finding the room, opening the door, and entering.

Yanco soldered her first robot at a computer camp the summer after eighth grade. As kids, she and her brother, now a math teacher, played whatever video games they could get their hands on; when Pac-Man got too easy, they played it with their feet. At Wellesley, she double-majored in philosophy and computer science and took advantage of the opportunity to cross-register at MIT, where she took classes in electrical engineering and computer vision; she ultimately completed her undergraduate thesis under an MIT advisor.