An electromagnetic device for manipulating a magnetic-responsive robotic device, and an electromagnetic apparatus incorporate one or more such electromagnetic device. The electromagnetic device includes a magnetic core 200 having a first portion and a second portion extends from one side of the first portion. The first portion has a first cross section and defining a first central axis. The second portion has a second cross section smaller than the first cross section, and defines a second central axis parallel to the first central axis. A first electromagnetic coil is arranged around the first cylindrical portion. A second electromagnetic coil is arranged around the second cylindrical portion.