Looking at the videos, it seems to be some kind of carbon nanotube sensor that checks the resistance of the water its dipped in. This is hooked up to an arduino

Looking at the videos, it seems to be some kind of carbon nanotube sensor that checks the resistance of the water its dipped in. This is hooked up to an arduino and the data is pushed to a smartphone via bluetooth. Not sure how she made the carbon nanotube detector, but I think people figured out a way to do it with a microwave oven? Seems dangerous, but very cool.