Science fiction writers and technologists have been predicting the arrival of robot butlers for the better part of a century. So far domestic robots have been relatively pedestrian: robot dogs, vacuum cleaners, lawn mowers. Rosie of The Jetsons fame? Not so much. 

That may be about to change. Behind the scenes, big tech companies are funding secret projects to develop robots. Amazon.com Inc has been working on a robot version of its Echo voice-activated speaker for a while now and this year began throwing more money and people at the effort. Alphabet Inc is also working on robots, and smartphone maker Huawei Technologies Inc is building a model for the Chinese market that will teach kids to speak English.