The ground-bound robots, developed by the science fiction-sounding company Starship Technologies, will be showing up any day in the nation’s capital and in Redwood City, California. They could soon be in up to 10 cities, ferrying groceries and other packages over what the company calls the “last mile,” from a neighborhood delivery “hub” to your front door, all for as little as $1 a trip. A second company, TeleRetail, plans to test its sidewalk robots in Washington and other cities, including Mountain View, California, next year. Like driverless cars, the delivery robots use cameras, GPS and radar to “see” their urban environment and navigate through it.