UK researchers are developing a self-powered toilet which turns human waste into clean water and even energy to charge mobile phones.
The "nano membrane toilet", being developed with funding from the Bill and Melinda Gates Foundation, aims to help bring sanitation into the homes of 2.5 billion people still without it in developing countries, without needing water supplies or sewage pipes.
The team at Cranfield University, Bedfordshire, say it could also be used in developed countries, for uses ranging from the military to luxury yachts, the construction industry or even as an odour-free alternative to the toilets widely used at music festivals.
PhD student Jake Larsson, one of the team working on the project, said: "The nano membrane toilet is a project that looks to serve the needs of people in developing countries to stop a major spread of disease, which is inadequate sanitation.
"It is a household scale toilet that produces clean water and manageable, pathogen-free, disposable waste, it's self-standing, it's small enough to fit in someone's home and there's even a little bit of energy left over to charge a mobile phone.
"It is very diverse. Not only it is for developing countries, but it's also useful for developed countries, maybe for the military, they're always in desolate places, or for the construction industry or even for yachts."
The toilet, activated once the lid is closed, rotates the bowl to carry the waste into a holding tank, maintaining an "odour barrier" to prevent smells, and using a sweep mechanism instead of a flush.
In the tank a "nano membrane" only allows through water molecules, separating it from solid waste and pathogens which are too large to pass through it.
The water which is collected is suitable for irrigating fields, washing or cleaning, and could even be made clean enough to drink, while the solid waste is passed into a gasifier which burns it, producing ash which can be used for agriculture.
Heat from burning the waste produces enough electricity to power the unit, and could even produce a little extra for mobile phone charging.
The Cranfield University team aims to start field testing the toilet in 2016.