Force-feedback mechanisms have been designed to simplify and enhance the human-vehicle interface. The increase in secondary controls within vehicle cockpits has created a desire for a simpler, more efficient human-vehicle interface. By consolidating various controls into a single, haptic feedback control device, information can be transmitted to the operator, without requiring the driver?s visual attention. In this paper Electro-Rheological Fluids (ERF) based actuated mechanisms are presented that provide haptic feedback. ERFs are liquids that respond mechanically to electric fields by changing their properties, such as viscosity and shear stress electroactively. Using the electrically controlled rheological properties of ERFs, we developed haptic devices that can resist human operator forces in a controlled and tunable fashion. The design of two types of ERF-based actuators and joystick is presented in detail. Their analytical model is derived, parametric analysis is performed, and experimental systems and data are presented.