Wireless Dual Mode Haptic Thimble based on Magnetoactive Rubber

This paper proposes a wireless dual mode haptic thimble based on magneto-active rubber (MAR) for providing kinesthetic and vibrotactile feedback without any electric wire. When the external magnetic field is applied to the MAR, ferro-magnetic particles in the MAR polarize and attract each other, causing the magnetic attraction force between the MAR and the external magnetic field generator (e.g., a solenoid). We can easily provide both the force and vibration to a user wearing the MAR thimble by controlling the solenoid. To improve the wearability and maximize the haptic performance, the best ratio of ingredients for fabricating the MAR thimble is determined through extensive experiments. The haptic behavior of the fabricated MAR thimble is quantitatively investigated. The experimental results show that the haptic thimble can generate a sufficient magnitude of force or vibration to simulate the user's finger for various haptic effects. Moreover, a transparent force rendering algorithm is proposed to compensate for non-linear force response. The potential of the system is further demonstrated in a distinctive virtual reality-based interaction scenario.