Airships demonstrate a law of increasing returns: doubling the length increases the surface area (and hence weight) by a factor of four while the volume (and hence lifting capacity) goes up by a factor of eight.

ECONOMIST: Pushing the envelope

Essentially a network of tiny wires, it features a larger surface area than flat electrodes, giving it the leverage it needs to convert more electricity in a smaller form factor.

ENGADGET: Nature-inspired nano-material builds a better electrode, points to greener future (video)