The struggling US maker of the Roomba robot vacuum cleaner has filed for bankruptcy protection. Fierce competition in the smart appliance sector has taken a toll on the company's finances.

Robot , the maker of the Roomba vacuum cleaner, filed for bankruptcy protection on Sunday, saying that it would go private after being bought by Picea Robotics, its primary manufacturer.

While humanoid robots from China and the US have captured the imagination of people for their skill at serving drinks, taking ...