"Unlike the United States or Europe, Japan is reluctant to allow in cheap foreign labourers," said Takashi Gomi, president of Canada-based Applied AI Systems Inc, whose company has developed a prototype of an "intelligent" wheelchair that can move around on its own and sense obstacles to avoid them.
"I don't think this will change easily in the next 20 to 30 years, so robots are about the only solution," said Gomi, a Canadian researcher born in Japan.
Right now, most robots are used in factories. But many Japanese researchers have begun developing mechanical helpers for use in homes, offices, hospitals and nursing facilities.
Turning to robots makes economic sense.
A government report said in May that annual demand for non-factory "service robots" may reach 1.1 trillion yen in 2015, when one in four Japanese is expected to be 65 or older.
Yoshiyuki Sankai is among those who see robots as the future of elderly healthcare.
A researcher at Japan's University of Tsukuba, Sankai has developed a robotic suit designed to make it easier for elderly people with weak muscles to move around or for care-givers to lift them.
The sleek, hi-tech get-up looks like a white suit of armour. It straps onto a person's arms, legs and back and is equipped with a computer, motors and sensors that detect electric nerve signals transmitted from the brain when a person tries to move his limbs.
"The big goal is to expand or strengthen the physical capability of humans"
Yoshiyuki Sankai, researcher, Japan's University of Tsukuba
When the sensors detect the nerve signals, the computer starts up the relevant motors to assist the person's motions. Sankai says the suit, dubbed "Hybrid Assistive Limb (HAL) 5", can let a person who can barely do an 80-kg leg press handle 180kg.
"The big goal is to expand or strengthen the physical capability of humans," said Sankai, who set up a venture firm last year to market the robot suit and plans to start leasing HAL-5 to the elderly and physically disabled in Japan this year.
Japan may face a shortage of young workers, but has an abundance of robots.
It was home to 44% of the nearly 801,000 industrial robots around the world at the end of 2003.
Although the market for "rehabilitation robots" - those aimed at assisting the elderly or physically disabled - is still in its infancy, they are gradually coming into use.
Yaskawa Electric Corp, a leading industrial robot maker, has been selling a rehabilitation robot since 2000, says Hidenori Tomisaki, a manager at Yaskawa's medical and assistive technology group.
Japan has plenty of robots but a
shortage of young workers
Its bedside robot assists the physical therapy of patients recovering from strokes or artificial knee replacement surgery, helping them move their legs with its mechanical arm.
"Some patients become worried or feel pain unless such exercises are conducted at a consistent speed," Tomisaki said.
Demand, however, has been limited, due partly to the cost.
The newest version, TEM LX2, is priced well over $30,000. Only five to six units have been sold per year since 2003.
Costs may eventually come down. Developing robots that react to people's whims is another matter.
Robot gurus at Tohoku University and Nomura Unison, an industrial machinery maker, say the key is to equip robots with the ability to detect intent or action.
That is what they had in mind when developing a Partner Ballroom Dance Robot that can dance a waltz.
The 1.65m, 100 kg robot looks like a woman in a dress and can execute five types of dance steps to match the moves of a human dance partner.
"We think that in the future, this technology can be applied to various areas including helping care for the elderly ... and for cooperation between humans and robots"
Nomura Unison president
It accomplishes this with a sensor that detects the force being applied to it by the human dancer and gauging how the person wants to dance based on such signals.
"We think that in the future, this technology can be applied to various areas including helping care for the elderly ... and for cooperation between humans and robots," said Minoru Nomura, president of Nomura Unison.
Robots over humans
Naoki Tanaka, managing director of Network Centre for Human Service Association, a non-profit network of groups involved in elderly care, says some of the people he works with may even prefer robots to humans when it comes to their care.
"There are people who say they would rather have a robot help them take a bath than rely on help from another person," he said.