Dull, dirty, and dangerous. For decades, the “Three D’s” were viewed as the ideal types of jobs for robots. A fourth D—domestic—was not so much in the discussion. And for good reason, says Steve Cousins, PhD ’97, executive director of the Stanford Robotics Center. Early robots—like hydraulic arms—were dangers themselves. “For the first 40 years of robotics actually doing work in the world, robots were kept behind safety cages,” Cousins says.