(CNN) -- Microsoft co-founder Bill Gates thinks one of the answers to improving health is in the bathroom.
A year ago, his foundation issued a challenge to universities to create a new toilet, launching a worldwide effort to improve sanitation.
This week the Bill & Melinda Gates Foundation announced who won the challenge.
California Institute of Technology was the big winner and was awarded $100,000 for its idea of a solar-powered toilet that generates hydrogen and electricity. The United Kingdom's Loughborough University won second place and was awarded $60,000 for a toilet that produces biological charcoal, minerals, and clean water. The University of Toronto in Canada garnered third place and $40,000 for a toilet that sanitizes feces and urine and recovers resources and clean water.
The new commodes are being showcased at a "Reinvent the Toilet Fair" Tuesday and Wednesday in Seattle.
The foundation also announced a second round of grants totaling some $3.4 million to organizations that are working to innovative latrines.
While many may not want to ponder creative ideas about human waste, the Bill & Melinda Gates Foundation says these creations are vitally important.
About 2.5 billion people don't have access to modern toilets, and this lack of access encourages the spread of diarrheal diseases, which are blamed for the deaths of 1.5 million children each year, according to the World Health Organization.
"Innovative solutions change people's lives for the better," Bill Gates said. "If we apply creative thinking to everyday challenges, such as dealing with human waste, we can fix some of the world's toughest problems."
The fair in Seattle will also bring together researchers, designers and investors from 29 countries, the Gates foundation says.
"Imagine what's possible if we continue to collaborate, stimulate new investment in this sector, and apply our ingenuity in the years ahead," said Gates. "Many of these innovations will not only revolutionize sanitation in the developing world, but also help transform our dependence on traditional flush toilets in wealthy nations."