In virtual reality (VR) applications various force profiles need to be reflected to the user through a haptic interface in a realistic and stable way. DC motors are the most common actuators in haptic interfaces. They can provide fast response but stability issues arise when simulating interactions with stiff surfaces. Brakes are also used in haptic devices since they can provide larger forces with less current consumption in a smaller actuator size, and are inherently stable due to their passive nature. However, they can only oppose motion hence cannot simulate elastic virtual objects.
We developed hybrid actuators by combining MR-brakes with motors, pneumatic cylinders or pneumatic muscles. Please click the links on the left to explore some of our research projects.