Vessel-sealing device including force-balance interface and electrosurgical system including same

A surgical instrument includes a housing having a shaft affixed thereto, a reciprocatable drive rod slideably disposed at least partially within the shaft, and a force applicator coupled to the drive rod. The shaft includes first and second jaw members attached to a distal end thereof, at least one of which movable relative to the other from a first position wherein the jaw members are disposed in spaced relation relative to one another to at least a second position closer to one another wherein the jaw members cooperate to grasp tissue therebetween. The force applicator and the drive rod mechanically communicate to impart movement to at least one of the jaw members. The bipolar forceps includes a handle assembly and a force-balance interface. The force-balance interface configured to translate a multiple of the user-applied force exerted on the handle assembly into the jaw members.