Eco Factor: Battery-free digital clock powered by lemons.
Florian Dussopt and Julie Girard have used lemons not to make lemonade, but to power a special clock that replaces battery power with lemon power. The clock comes with a wooden plank that has two spikes of copper and zinc built into it. All the user has to do is to cut a lemon in two halves and place them on each spike. The copper and zinc spikes start an electrolysis reaction in presence of citric acid that comes from lemons to generate electricity, which is used to run the clock. A single lemon can power the clock for a week.
The Dark Side:
The clock might not just look as clean after a week of lemon electrolysis as it’s shown in the image above. Moreover, lemon juice might attract all sorts of insects towards it.