MIT built a 300-gram robot that flies through the sky, dives underwater and takes off again

The Flapping-wing Aerial-aquatic Vehicle (FAAV), developed by engineers at MIT and EPFL, is a 300-gram robot designed to mimic the diving birds like the Atlantic puffin. It is the first machine capable of completing the full cycle of swimming, diving, and launching back into the sky using its wings rather than separate propellers or legs.