Various embodiments relate to magnetically moveable displacement devices or robotic devices. Particular embodiments provide systems and corresponding methods for magnetically moving multiple movable robots relative to one or more working surfaces of respective one or more work bodies, and for moving robots between the one or more work bodies via transfer devices. Robots can carry one or more objects among different locations, manipulate carried objects, and/or interact with their surroundings for particular functionality including but not limited to assembly, packaging, inspection, 3D printing, test, laboratory automation, etc. A mechanical link may be mounted on planar motion units such as said robots.