A machine that turns sweat into drinking water

The device spins and heats the material to remove the sweat and then passes the vapour through a special membrane designed to only let water molecules get through, BBC reported.

Since its launch, its creators said more than 1,000 people have "drunk other's sweat" in Gothenburg city. The experts said the liquid was "cleaner" than local tap water.

The device was built for the Unicef to promote a campaign highlighting the fact that 780 million people in the world lack access to clean water.

The machine was designed and built by engineer Andreas Hammar, known locally for his appearances on TV tech show "Mekatronik".

Hammar said the critical part of the sweat machine was a water purification component developed by the HVR company in collaboration with Sweden's Royal Institute of Technology.

"It uses a technique called membrane distillation," he told BBC.

"We use a substance that only lets steam through but keeps bacteria, salts, clothing fibres and other substances out."

"They have something similar on the International Space Station to treat astronaut's urine - but our machine was cheaper to build.

"The amount of water it produces depends on how sweaty the person is - but one person's T-shirt typically produces 10 ml, roughly a mouthful," he said.

Mattias Ronge, chief executive of Stockholm-based advertising agency Deportivo - which organised the event - told BBC the machine helped raise awareness for Unicef, but in reality had its limitations.

He said the machine "will never be mass produced there are better solutions out there such as water purifying pills".