Some robotic arms may include vacuum-based grippers. Detecting the seal quality between each vacuum assembly of the gripper and a grasped object may enable reactivation of some vacuum assemblies, thereby improving the grasp. One embodiment of a method may include activating each of a plurality of vacuum assemblies of a robotic gripper by supplying a vacuum to each vacuum assembly, determining, for each of the activated vacuum assemblies, a first respective seal quality of the vacuum assembly with a first grasped object, deactivating one or more of the activated vacuum assemblies based, at least in part, on the first respective seal qualities, and reactivating each of the deactivated vacuum assemblies within a reactivation interval.

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.