ER Clutches as Torque Controlling Devices for Artificial Wrists

Electrorheological (ER) fluids are a class of smart materials that exhibit significant reversible changes in their mechanical properties under the influence of an applied electric field. In the present work, the applicability of these materials as a torque control (viscous coupling) device for an artificial wrist is presented. The output torque capacity of the clutch is controlled by applying the appropriate electric field. A PID controller is used to achieve the desire output torque. The application of an electric field between the input and output parts alters the viscosity of the fluid and consequently the output torque for the wrist. Both homogeneous and non- homogeneous ER fluids are considered as the working liquid in the clutch. Based on the results presented herein, the desirable output torque can be achieved. However, the applied particle type required higher input voltage.