Propelling boats with liquid magnet propellers may offer a safer alternative for powering boats

Robotic boats with propellers made of liquid magnets could be a safer alternative to solid metal blades, which can damage wildlife.

Atsushi Shintake and colleagues at the University of Electro-Communications in Chofu, Japan, have created a prototype seaplane with a propeller made of ferrofluid, made of magnetic iron oxide nanoparticles suspended in oil. It is controlled by an electromagnet that turns on and off at high speed.