Abstract: A magneto-rheological fluid device including a housing defining a cavity, a piston slidably disposed in the cavity to divide the cavity into first and second portions, a passage defined on an exterior surface of the piston fluidly coupling the first and second portions of the cavity, a magneto-rheological fluid disposed in the cavity such that motion of the piston is damped by flow of the magneto-rheological fluid through the passage and a magnet disposed to produce a magnetic field within the cavity substantially parallel to the motion of the piston at the exterior surface of the piston.