With the proprietary ER fluids available today it is not a viable proposition to develop a high force damper within the available space envelope. ER fluids are simply not strong enough and attempts to overcome this limitation by increasing the size of the damper result in excessive power demands. A bi-directional controllable damper has been developed that overcomes the limitations of available ER fluids and allows the development of exceptionally high forces with low control power. The forces generated by the damper are not directly linked to the performance of the ER fluid and both very low un-energised and very high energised forces can be developed. The nature of the design permits a wide range of controllable forces and force profiles. The main limitations of existing ER fluids, that of low excess shear stress, has been overcome with a novel and unique damper design. The performance of the damper is not limited by the performance of the ER fluid and controllable dampers can be developed that are able to generate almost unlimited forces. Two versions, for specific niche markets, have been fully developed to the preproduction stage.