Photos: Clean-tech start-ups swing for the fences

Can someone improve on the internal combustion engine? Sanderson Engine Development showed off its motor, which company executives said can produce the same amount of power as an internal combustion or diesel engine can--at about two-thirds of the size.

The design, which eliminates the crankshaft, can be used in a wide range of motors, from fuel-efficient cars to wind turbines. The company, which has prototypes, is looking to raise money and license its technology, executives said.