The current model of robo-fly is tethered to a small, off-board power source but Dr Ma says the next step will be to miniaturise the other bits of technology that will be needed to create a "fully wireless flying robot".

BBC: Robotic insect: World's smallest flying robot takes off

Part of the rationale for big government-sponsored rebates on what is an otherwise uneconomic source of power is the strategic benefit of distributing small-scale power generation across the landscape rather than focusing it in a hulking coal or nuclear plant.

FORBES: Magazine Article

Resembling a small child wearing an astronaut outfit with a backpack (for the battery power source), the ASIMO could walk on two feet at speeds at over three miles per hour.

FORBES: Reflections on Personal Robots, Backwards and Forwards

You wouldn't immediately think of the ear's cochlea as an energy source, but MIT knows that every mammal effectively has a pair of very small power plants because of the ionized environment.

ENGADGET: MIT ear-powered wireless sensor sustains its charge through sound

Second, governments should not pick winners or give out extensive subsidies. (Translation: Ethanol is a bad idea, and other existing "renewables, " such as wind power, are unlikely to ever be more than a niche source.) Better to have a small carbon tax to place a price floor for competing technologies, and offer large cash prizes, similar to the X-Prize for private space flight, for specified energy breakthroughs.

FORBES: Magazine Article