In this paper, a new skin tissue which can emulate the stiffness of several organs of human being is proposed and analyzed utilizing a magneto-rheological (MR) fluid. It is called MR skin. The proposed skin can be applied to the robot assisted surgery manipulated by the haptic devices as a controllable tactile sensor. In order to formulate the device, the valve networks are embedded inside the structure of the master actuator. These valves use the flow mode and shear mode of MR fluid for the pressure control. The deformation equation of the MR skin is derived and the external force contacting to the MR skin is also analyzed. After formulating, the proposed tactile display is optimized by using the finite element method. In the optimization process, many different forces are applied to view different deformation of MR skin with different pressures. It is shown via the optimization that the results satisfy the initial requirements of the design. This result directly indicates that the proposed MR skin structure is feasible in the manufacturing sense and applicable to haptic devices for robotic surgery.
Magnetorheological (MR) fluid is smart material that behaves differently with an applied magnetic field. MR brake consists of the fluid with a magnetic source to produce sufficient torque for the braking application. This paper takes the multidisc MR brake with a new approach to produce more uniform magnetic field using the Helmholtz coil setup and placing the other coils inside of the braking discs. The system is optimized for the resulting torque that can be used within the leg exoskeleton for walking support.