Wheelchairs and windmills are among the winners of the 2010 World changing ideas Video contest, sponsored by Scientific American and sciVee.tv, the online science video site. the entries showcase innovative ways to build a cleaner, healthier or safer world.

WINNER

The Leveraged Freedom Chair
Idea: MIT Mobility Lab
Video: Amos Winter and the MIT News Office
This wheelchair features a lever-powered, geared drivetrain that takes it over sand, dirt and rough terrain often confronted in developing countries. the judges hailed it as "ingenious, simple and doable now. it could change one person’s whole world."

RUNNERS-UP

Sourcemap
Idea and video:
Leonardo Bonanni
His crowdsourced Web site tracks the environmental footprint of product supply chains.

Urban Power
Idea: Mark Maynard
Video: Michael Garjian
This backyard wind turbine generates electricity in slow as well as fast breezes.