New ways to construct contactless magnetic gears

The new milk frother you are using to prepare your cappuccino is likely using magnetic gears. Magnetic gears transmit rotary motion like mechanical gears but instead of teeth they use magnetic attraction and repulsion between rotating magnets. Dr Johannes Schönke, a postdoctoral scholar at the Okinawa Institute of Science and Technology Graduate University (OIST), published in Physical Review Applied a theory which extends the possibilities and applications for smooth ma