Forget the frightening androids of dystopian sci-fi, the future of robots is cute polar bears that can lift elderly people into and out of bed.

The "Robear" has a cub-like face with big doey eyes, but packs enough power to transfer frail patients from a wheelchair to a bed or a bath, Japan's Riken institute said Tuesday.

"The polar cub-like look is aimed at radiating an atmosphere of strength, geniality and cleanliness at the same time," research leader Toshiharu Mukai told AFP.

"We voted for this design among options presented by our designer. We hope to commercialise the robot in the not-too distant future," he added.

A historically low birth rate and ever-increasing life expectancy means Japan's population of elderly people is growing, while the pool of youngsters to look after them is shrinking.

A reluctance to accept large-scale immigration means an increasing reliance on robots, especially to perform physically difficult work.

This frequently combines with the country's love of all things cute, to produce machines with disarming faces and child-like voices.

"As Japan is ageing with fewer children, the problem of a shortage in caregivers for the elderly is getting serious," Riken said in a statement.

"Expectations are high that robotics will help resolve this problem," it said.