Tactile display and vibrotactile pattern recognition on the torso

A wirelessly controlled tactile display has been designed, fabricated and tested for use as a navigation aid. The display comprises a 4 x 4 array of vibrating motors that is mounted on a waist band and stimulates the skin across the lower back. Three types of electromechanical actuators were evaluated for use in the display; based on their mechanical performance and power requirements, two of these motors were then used to fabricate tactile displays. The performance of the displays and the wireless tactile control units was assessed experimentally by having subjects identify which of eight possible vibrotactile patterns was presented to the lower back. The results indicated that subjects could recognize the vibrotactile patterns with almost perfect accuracy and that there was no difference between the two types of motor used for the displays. Moreover, the ability to recognize the pattern of vibrotactile stimulation was superior on the back as compared to the forearm. A further experiment confirmed that the tactile display can be used as a navigation aid outdoors and that the vibrotactile patterns presented can be interpreted as directional or instructional cues with almost perfect accuracy.