Tricycle for Quad-Amputee
This was a tricycle built by several capstone and senior mechanical design course students for a quad amputee boy - Kyle Romano.  This is an excellent example of bringing joy and service through engineering.  

The tricycle is powered by Kyle doing abdominal crunches.  He steers the tricycle with his left stub, and uses the right stub to change gears and use brakes.

The tricycle was designed so that it would fit him through his adult years.