Disposable paper battery is activated by a drop of tap water
https://www.newscientist.com/article/2330693-disposable-paper-battery-is-activated-by-a-drop-of-tap-water/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home
Disposable paper battery is activated by a drop of tap water