A future in which it is difficult to tell man and machine apart could soon become reality, scientists say, after recent robotic breakthroughs in Japan.
But as the once-fantastical idea of wise-cracking android sidekicks takes form in laboratories -- and the gap between humans and robots narrows -- society faces ethical and legal complications as yet undreamed of, they warn.
"Already computers have surpassed human ability," leading Japanese roboticist Hiroshi Ishiguro told AFP. "Robots will be very clever soon."
Science fiction's rapid slide towards science fact owes much to the likes of Ishiguro, who has an android copy of himself that he sends on overseas business trips in his place. "It saves me time," he smiled. "The upper torso and lower torso you can pack in two big suitcases. The head is very fragile -- it goes as carry-on baggage."
Robots already perform a wide variety of tasks in Japan: they cook noodles, help patients undergo physiotherapy and have been used in the clean-up after the 2011 nuclear meltdown at Fukushima. South Korea deploys jellyfish-terminating robots, while a robot with artificial intelligence able to analyze market trends has become a company director in Hong Kong.
One day, predict future-gazers, robots will perform all kinds of household chores, monitor the sick, and even serve up cappuccinos. But will they look like us?
Ishiguro created his doppelgänger from powerful electronics, complex moving parts, silicone rubber and hair from his own scalp.
"If we have enough knowledge about humans, we can create more human-like robots," he said after unveiling last month what he claimed was the world's first news-reading android in Tokyo. "That knowledge usually comes from neuroscience or cognitive science.
"More important is robots and androids as a mirror to reflect humanity. Once we become friends, the boundary between human and robot disappears," added Ishiguro, a professor at Osaka University.
The blurring of that line has long been a source of worry for humanity, as often depicted in popular culture. The 1982 Hollywood cult film Blade Runner, which is set in 2019, features genetically engineered robots called replicants that are visually indistinguishable from humans, but physically superior and able to withstand pain.
The film's protagonist, played by Harrison Ford, is given the task of tracking down and killing replicants that have escaped and are living among us. His problem is knowing the difference.