Put down your smartphones for a moment, kids, and do some real science. Build this plane with your hands, power it with the sun. Batteries not included. No, not because the seller is cheap but because this plane doesn’t need them. It can be assembled in less than 20 minutes and you won’t even need any special tools or glues – just your hands. Your kids will learn basic mechanical engineering, aeronautics, electronics and renewable energy. Volta Flyer has a thin-film, flexible silicon solar panel which helps it to fly without the need for batteries.