a rotary damper is disclosed . the rotary damper comprises a first and a second plurality of plates disposed within a housing . the first and second pluralities of plates are interleaved and are capable of moving relative to one another . a magnetorheological fluid contained within the housing resides in the interleave of the first and second plurality of plates . a magnetic flux generator drives a magnetic flux through the magnetorheological fluid in the interleave in a direction transverse to the orientation of the plates and is capable of varying the strength of the driven magnetic flux . the magnetic flux aligns the magnetic particles suspended in the magnetorheological fluid , increasing the shear strength of the magnetorheological fluid , which in turn resists motion between the first and second plurality of plates , acting as a damper .