CNN — The top-hatted “drinking bird,” once a fixture in science classrooms for demonstrating the basics of thermodynamics, is making a surprising comeback — as the inspiration for a new clean-energy generator that could one day power your watch and phone. Scientists in Hong Kong and China have used the famous toy, also known as the “Dippy Bird,” to develop an engine capable of using the power of water evaporation to generate electricity, according to a study published Thursday in the journal Dev...