Thomas Edison famously said that genius is 1 percent inspiration and 99 percent perspiration — words that could well apply to a new machine promoted by UNICEF that turns human sweat into drinking water.
The Sweat Machine extracts moisture from worn clothes by spinning and heating them, then filters the resulting liquid so that only pure water remains. It was built by Swedish engineer and TV personality Andreas Hammar, and uses a technology developed by Sweden's Royal Institute of Technology and the water purification company HVR.
The purification technique, known as membrane distillation, uses a Gor-Tex-like material as a filter that "lets only steam through but keeps bacteria, salts, clothing fibers and other substances out," Hammar is quoted as saying in The Independent.
"They have something similar on the [International] Space Station to treat astronauts' urine — but our machine was cheaper to build," Hammar says. "The amount of water it produces depends on how sweaty the person is, but one person's T-shirt typically produces 10ml [0.3oz], roughly a mouthful."
Here's a video from UNICEF on the making of the Sweat Machine, which features the bearded inventor:
A more common technology for removing salt and other impurities from water is known as reverse osmosis, which uses lots of energy to produce the extremely high pressure required to force raw water through a semi-permeable membrane. You can see a diagram of how it works here.
UNICEF is using the Sweat Machine as the centerpiece of a campaign to raise awareness about the lack of clean drinking water for children. The United Nations agency estimates that 780 million people worldwide lack access to clean drinking water.
"We wanted to raise this subject in a new, playful and engaging way," Peter Westberg, deputy executive director at UNICEF Sweden, says in a statement. "Our Sweat Machine is a reminder that we all share the same water. We all drink and sweat in the same way, regardless of how we look or what language we speak. Water is everyone's responsibility and concern."