Neodymium Grasper

Very simple and surprisingly reliable magnetic lift. It is very lightweight, so you can even apply to robots such as delta.
I have used MG90S servo and neodymium magnet d:8mm h:10mm. This servo was a little bit too weak to unhook the magnet from heavy object, so I used plastic disc to increase the distance between magnet and object. Now it can hold even 150g steel objects!