US Patent 7661680 Ferrofluid magnetic seal

A ferrofluid based magnetic seal, comprising at least one gasket, the at least one gasket comprising a flexible, closed cell material, such as, without limitation, neoprene, polyvinylchloride, or plastic, and a ferrofluid core; a first housing, wherein a first face of the first housing is designed to receive at least a portion of the gasket; a second housing, wherein a first face of the second housing is designed to receive at least a portion of at least one magnet; and wherein the at least one magnet is positioned such that when the first housing and the second housing are in close proximity, the at least one magnet is positioned substantially along the length of the at least one gasket.