'BOTS ROOMBA REPURPOSED

Fans of the whirring, circular robot vacuum, the Roomba, love to speculate about the next automated home-helper to come out of the labs of Boston firm iRobot. Is it a machine that mows the lawn, walks the dog or watches the elderly? "Those are all further down the road," says iRobot CEO Colin Angle. The sequel to the successful Roomba--1.2 million sold, the most ever for a home robot--will stick a little closer to familiar territory: it's an automated mop called Scooba, which looks and sounds like the Roomba but wets, washes and dries floors.

Scientists at iRobot have been trying to solve the delicate technical challenges of a mop-bot for more than two years. Early prototypes used off-the-shelf detergent and became bubble-spewing machines that spun their wheels on the wet surface. Last year iRobot reached out for help to an unlikely source: the 92-year-old, Oakland, Calif.-based Clorox. It was the start of a beautiful friendship. Chemists at Clorox developed a concentrated soap that was easy on the robot but hard on dirt, while mechanical engineers at iRobot searched for the right material to maintain wheel traction. At one point, engineers considered using leather wheel socks but ultimately discovered a workable rubber compound. Early Scooba trials took place on Clorox's "torture floors," the brutally filthy test surfaces in its research and development center.

Scooba, which will go on sale by the end of the year at a still undecided price, works in four stages. A high-velocity jet stream pushes loose particles into a dirty-water compartment. Then two nozzles squirt cleaning fluid from a clean tank, and a mustache brush spreads it around. A scrubbing brush then rubs the floor and, finally, a squeegee sucks the dirty liquid into the dirty tank. iRobot's sales pitch: the separate clean and dirty compartments allow Scooba to do a better job than humans, who tend to spread dirty water around. "We are not just going to replace mopping, we are going to obsolete it," Angle says. Humans, we imagine, will gladly turn over this particular chore to our automated friends.