Scientists have invented a skin patch that generates power from sweat, according to New Scientist. Sweat powered a radio for two days and could eventually be used for devices to monitor medical conditions.
How it works: The patch contains enzymes that replace batteries and "feed off sweat to provide power." Joseph Wang, a member of the team from U.C. San Diego that worked on the technology, told New Scientist: "If you were out for a run, you would be able to power a mobile device."
What's next: Right now there is extensive research into flexible sensors and electronics that would allow people to continually monitor health conditions through wearable devices. Wang hopes these sensors could eventually generate "enough power for a Bluetooth connection" so results could be read off a smartphone.