Japanese researchers have developed a new fuel cell that can run on human blood.

The team at Tohoku University's Department of Bioengineering and Robotics have developed the tiny fuel cell to power implanted medical devices like pacemakers or blood sugar monitors.

It can produce 0.2 milliwatts of power, enough for simple processing and radio communication.

The power is generated from electrons found in glucose, the naturally occurring sugars found in the blood stream. The medium used to do this is non-toxic and could be used internally without risk, according to the researchers.

"Since the electron mediator is based on vitamin K3, which exists in human bodies, it excels in safety and could generate power from blood as an implant-type fuel cell," said the laboratory team in a statement.

Tohoku University has something of a reputation for blue-sky research. Earlier this month it announced the completion of research into the perfect angle for skipping stones across a lake.