The Small Business Technology Transfer Research (STTR) Phase I project will demonstrate the feasibility of developing a compressible magnetorheological (CMR) fluid. Magnetorheological fluids consist of magnetizable particles suspended in a carrier fluid. The compression of a fluid is the measured change of volume from an applied external force. The CMR fluid, when used in a damper (or a shock absorber) for the suspension system of land vehicles, will be able to simultaneously provide controllable damping and spring effects. The controllable damping comes from the viscosity change (under a magnetic field) of the fluids. Therefore, a damper that contains CMR fluid can replace both the regular passive damper and the spring in the suspension of vehicles. This will result in reduction of weight, increased mobility and controllability of the vehicle's motion; and will prevent roll over, particularly in rough terrains. In the proposed work, the CMR fluids developed will also be characterized in terms of rheological behavior and compressibility.<br/><br/>In addition to suspension systems of automobiles, the CMR fluid may be used in off-road vehicles, motorcycles, military high-payload ground vehicles, high speed trains, and recoil systems. The proposed project will also provide graduate students training in multi-disciplinary subjects including chemistry, materials and thermodynamics.