TOKYO -- At a university lab in a Tokyo suburb, engineering students are wiring a rubbery robot face to simulate six basic expressions: anger, fear, sadness, happiness, surprise and disgust.
Hooked up to a database of words clustered by association, the robot responds to the word "war" by quivering in what looks like disgust and fear. It hears "love," and it smiles.
"To live among people, robots need to handle complex social tasks," said project leader Junichi Takeno of Meiji University. "Robots will need to work with emotions, to understand and eventually feel them."
While robots are a long way from matching human
emotional complexity, the country is perhaps the closest
to a future where humans and intelligent robots live side by side and interact socially.
Robots are taken for granted in Japanese factories. Robots make sushi. Robots plant rice and tend paddies.
There are robots serving as receptionists, vacuuming offices, spoon-feeding the elderly. They serve tea, greet company guests and chatter at public technology displays. Now startups are putting out robotic home helpers.
They aren't all humanoid. The Paro is a furry robot seal fitted with sensors beneath its fur and whiskers, designed to comfort the lonely, opening and closing its eyes and moving its flippers.
For Japan, the robotics revolution is an imperative. With more than a fifth of the population 65 or older, the country is banking on robots to replenish the work force and care for the elderly.
In the past several years, the government has funded a plethora of robotics-related efforts, including about $42 million for the first phase of a humanoid robotics project, and $10 million a year from 2006 to 2010 to develop key robot technologies.
The government estimates the industry could surge from $5.2 billion in 2006 to $26 billion in 2010 and $70 billion by 2025.
Still, Japan faces a challenge in making the leap from toys and experimental robots to full-blown human replacements that people can afford and use safely.
"People are still asking whether people really want robots running around their homes, and folding their clothes," said Damian Thong, senior technology analyst at Macquarie Bank in Tokyo. "But then again, Japan's the only country in the world where everyone has an electric toilet. We could be looking at a robotics revolution."
That revolution has been going on quietly for some time.
Japan is an industrial robot powerhouse. More than 370,000 robots worked at factories across Japan in 2005, about 40 percent of the global total and 32 robots for every 1,000 Japanese manufacturing employees, according to a recent report by Macquarie, which had no numbers from subsequent years.
And they won't be claiming overtime or drawing pensions when they retire.
"The cost of machinery is going down, while labor costs are rising," said Eimei Onaga, CEO of Innovation Matrix Inc., a company that distributes Japanese robotics technology in the United States. "Soon, robots could even replace low-cost workers at small firms, greatly boosting productivity."
That's just what the Japanese government has been counting on. A 2007 national technology road map by the Trade Ministry calls for 1 million industrial robots to be installed throughout the country by 2025.
A robot can replace about 10 employees, the road map assumes -- meaning Japan's future million-robot army of workers could take the place of 10 million humans. That's about 15 percent of the current work force.
Meanwhile, robotics technology is being used to spur advances in other fields. It's used to build more complex cars, for instance, and surgical equipment.
The logical next step is robots in everyday life.
At a hospital in Aizu Wakamatsu, 190 miles north of Tokyo, a child-sized robot guides patients to and from the outpatients' surgery area.
The robot, made by startup Tmsk, sports perky catlike ears, recites simple greetings, uses sensors to detect and warn people in the way, and prints out maps of the hospital.
The Aizu Chuo Hospital spent about $557,000 installing three robots to test patients' reactions. The response has been overwhelmingly positive, said spokesman Naoya Narita.
"We feel this is a good division of labor. Robots won't ever become doctors, but they can be guides and receptionists," Narita said.
Still, the machines hadn't won over all seniors in the hospital waiting room one morning.
"It just told us to get out of the way!" huffed wheelchair-bound Hiroshi Asami, 81. "It's a robot. It's the one who should get out my way."
Another roadblock is money.
For all its research, Japan has not come up with a commercially successful robot. Mitsubishi Heavy Industries Ltd. failed to sell even one of its toddler-sized Wakamaru robots, launched in 2003 as domestic helpers.
Though initially popular, Sony Corp. pulled the plug on its robot dog, Aibo, in 2006, just seven years after its launch. With a price tag of $2,000, Aibo never broke into the mass market.
One of the only commercially successful consumer robots is made by U.S. company iRobot Corp. The Roomba vacuum cleaner robot is self-propelled and can clean rooms without supervision.
"We can pretty much make anything, but we have to ask, what are people actually going to buy?" said iRobot CEO Helen Greiner. The company has sold 2.5 million Roombas -- which retail for as little as $120 -- since the line was launched in 2002.
Still, with the correct approach, robots could provide a wealth of consumer goods, Greiner said at a recent convention.
For Hiroshi Ishiguro, a researcher at Osaka University, the key is to make robots that look like human beings. His Geminoid robot looks uncannily like himself -- down to the black, wiry hair and slight tan.
"One day, they will live among us," he said. "Then you'd have to ask me: 'Are you human? Or a robot?' "