According to one embodiment, a trim actuator for a pilot input device includes a driven member and a driving member configured to receive mechanical energy from a power source. A magnetorheological (MR) fluid is disposed between the driving member and the driven member and configured to transmit a variable amount of mechanical energy from the driving member to the driven member. An output member configured to be coupled between the driven member and the pilot input device. A magnetic circuit configured to deliver a magnetic field towards the MR fluid. The magnetic circuit is configured to control movement of the pilot input device by varying the strength of the magnetic field delivered towards the first MR fluid.