Every Thursday night, inside a converted shipping container on the island of Maui, the Maui Makers meet up to share tools, time, and knowledge with the community for the purpose of making things. Thursday before last, MM member Ryan showed up with a laser...powered by passion fruit!
Lilikoi (aka Passion Fruit, Passiflora Edulis) is a vine that grows all over our wet Maui regions. It can produce LOTS of fruit—which can make a mess for owners, and a bonanza for bugs. Ryan was cleaning up a whole bunch of them at his home and tasting one, realized it was pretty acidic. Being a curious Maker, he thought "Hmmm I wonder if you could make a power source with this?"
Ryan grabbed some anodized bolts (source of zinc), some thin copper pipe, wire, switches, LEDs, capacitor, and built himself a nice demonstration Veggie Battery. And since Ryan loves lasers, he grabbed a small green laser and added it to the board.
At 3 to 3.8 volts, Ryan won't be using the laser to gun down stormtroopers anytime soon, but it's still an interesting source of renewable energy. Provided he doesn't eat them all.