A few years ago, she brought the "lemon battery" to classrooms through Penn State's Science U program. Middle schoolers got particularly invested in the experimental possibilities.

There are a whole bunch of high school science experiments out there that are useful for teaching students the basics of biology, physics, and chemistry. One of the classics is the lemon battery. [… ...

You can build your very own lemon battery using Science U's design here, written by Fortunato and Christopher Gorski of Penn State College of Engineering.