MATTHIAS BORK

Global chief engineer, fuel cell propulsion systems, General Motors

Chosen because: Bork, 52, is responsible for designing, developing and validating all of GM's fuel cell propulsion systems, which have produced prototypes of the Chevrolet Silverado and Equinox. GM has invested more than $1 billion in development of hydrogen vehicles.

Quote: "We're at a stage of the technology where we have managed to achieve durability" over a 10-year vehicle life cycle. "Now we still have to crack the last nut: to get the cost down to a level that would support high-volume commercialization."