Sep 07, 2019

The reason you're seeing it all the time is probably because roboticists are very excited about using external magnetic fields to create smaller designs that don't require carrying a power source, without worrying whether those are still "robots".

For example, the best paper award at the Robotics: Science and Systems conference this year was won by a magnetic jellyfish:

Maybe the magnet should be counted as part of the robot, with the moving parts being analogous to a gripper.