In case anyone hasn't seen it or wants to develop
their next project here is one. It is environmentally friendly (chemical &
material science), deals with transportation, electrical engineering,
instrumentation, mechanical engineering, sustainable engineering. If one thinks
a little out of the box I'm sure you can come up with some other benefits and
classifications.
http://inhabitat.com/toilet-bike-neo-crazy-poop-powered-motorcycle-to-travel-across-japan/toilet-bike-neo-poo-powered-motorcycle-2/?extend=1
Good Luck, Old Salt