Romantic human-robot relationships are no longer the stuff of science fiction – researchers expect them to become reality within four decades.

And they do not mean simply, mechanical sex. “I am talking about loving relationships about 40 years from now,” David Levy, author of the book Love+sex with robots, said at an international conference held last week at the University of Maastricht in the south east of the country.

“… when there are robots that have also emotions, personality, consciousness. They can talk to you, they can make you laugh. They can … say they love you just like a human would say ‘I love you’, and say it as though they mean it …”

Robots as sex toys should already be on the market within five years, predicted Levy, “a sort of an upgrade of the sex dolls on sale now”.

These would have electronic speech and sensors that make them utter “nice sounds” when a human caresses their “erogenous zones”.

But to build robots as real partners would take a bit longer, with conversation skills being the main obstacle for developers.