Green Science - Robot Solar

My son spent a whole afternoon building different versions using bottle caps and cardboard, and it actually crawls across the driveway when the sun hits the solar panel. The fact that it needs zero batteries is a huge plus for me.

My 8-year-old was thrilled when the robot finally took its first steps on a sunny afternoon — the solar panel really does work without any batteries. We've already repurposed a soda can and bottle caps for two different body configurations, and it keeps him entertained for hours.

My kids spent an entire weekend rebuilding this thing into different creatures using old bottles and cans. The solar panel picked up enough light through a window to get the motor spinning, though it really comes alive in direct sun. Great way to teach engineering basics without a single battery.