https://www.youtube.com/watch?v=Uc4CD1aEFwE Fifteen-year-old Angelo Casimiro from the Philippines has just invented a smart shoe insole that produces enough electricity when you walk to charge small USB devices. The gizmo consists of piezoelectric materials, which, as Angela explains, can generate an alternating current voltage when actuated. (Solid materials like certain ceramics and salts exhibit this effect, which... Continue Reading →