The foundation started by the Microsoft founder turned philanthropist is already busy funding health research and programs, college scholarships and a host of other do-good ventures. Now it is turning to a prevalent problem for the urban poor and the developing world: the lack of a hygienic place to poop.
Sanitation has actually been a pressing concern throughout human history, since there's a lot of nasty bacteria hiding out in a person's waste. Fecal contamination of water supplies is linked to a host of deadly diseases: cholera, hepatitis, and dysentery, just to name a few.
Archaeologists have unearthed evidence of ancient sanitation systems in Bronze Age Indus Valley Civilization - sewer systems made of smooth bricks with wooden screens to catch solid wastes, wells for homes, and covered drains. Romans received water through a system of aqueducts, which were also used in Greece and Assyria.
A flush toilet was first described by British writer James Harington, in his 1896 book "A New Discourse upon a Stale Subject: The Metamorphosis of Ajax." Harington had installed an 'Ajax' water closet in his home, and offered practical advice on how to build one in his book, which was also rife with allusions and "dreadful puns," according to the Stoke-on-Trent City Council.
Current toilets require lots of water and a massive sewer infrastructure to work - and for around 2.5 billion people, especially those living in developing countries, those things are in short supply. Fecal contamination that could be easily prevented by access to a toilet is thought to lead to the deaths of 1.5 million children every year.
The Gates Foundation wants to fund a toilet that works without a septic system, electricity or running water, costs about 5 cents per day, doesn't pollute, and ideally uses renewable energy sources and can recycle human waste into useful things like fertilizer.
At a "toilet fair" in Seattle this past Tuesday and Wednesday, participants in the Gates Foundation's "Reinvent the Toilet Challenge" exhibited their next-generation devices that aim to put human waste to work.
The winning toilet came from Caltech researchers, who received a $100,000 prize for designing a solar-powered toilet that generates electricity and hydrogen. Coming in second was a toilet from Britain that spins poop into charcoal. A toilet developed at the University of Toronto came in third.
The foundation also announced four second-round grants totaling nearly $3.4 million. Cranfield University in the UK was given nearly $814,000 to help develop its toilet, which uses a hand-operated vacuum pump and membrane system to vaporize water out of human waste and turn the leftover solids into fertilizer.
The Gates Foundation also gave about $780,000 to the University of Colorado Boulder to help them make a toilet that disinfects urine and feces using concentrated sunlight.
"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," Gates said in a statement Tuesday.
A video produced by the Gates Foundation was more direct: "let's get our s--- together and do it."