Wow, that was fast. Just last January we told you about the Energy Department's search for a transformative new design for lightweight vehicles, and the agency is has already picked a winner. "WaterBone" sounds a little naughty, but it perfectly describes the winning concept, which combines the aerodynamics of a water droplet with the lightweight but sturdy structure of bones.

The lightweight vehicle design competition, called the LITECAR Challenge, is being conducted by the Energy Department's cutting-edge funding agency, ARPA-E (Advanced Research Projects Agency – Energy), so chances are good that some of the new concept will make it into the electric vehicle marketplace. That's good news for the EV sector, since anything you can do to shave off weight will work in favor of increased battery range.

Looking For Mr. LITECAR

A breakthrough in lightweight vehicle design would also have huge implications for fuel efficiency in the gasmobile market, so LITECAR isn't aimed exclusively at electric vehicles (the acronym stands for Lightweight Technologies Enabling Complete Automotive Redesign,).

However, we're thinking that EVs will be first in line when this sort of thing hits the market, partly because of the linkage with 3D-printing. When the LITECAR Challenge was launched in January, ARPA-E made it pretty clear that 3-D printed designs would be especially welcome.

That's no surprise since the curator of the competition is Local Motors, best known for its 3-D printed lightweight vehicles.

Sure enough, 3-D printing features prominently in the winning WaterBone entry.

Formally titled the "Aerodynamic Water Droplet with Strong Lightweight Bone Structure," the new lightweight vehicle design was cooked up by a team from the School of Engineering and Technology at Indiana University-Purdue University Indianapolis.

The droplet-inspired outer shape or "envelope" is embedded with a rib-like frame, which is 3-D-printed from aluminum alloy foam. Though lightweight, the frame was sturdy enough to convince the LITECAR judges that WaterBone met the safety standards of the competition.