Development of Finger-mounted High-density Pin-Array Haptic Display

The presentation of virtual object shapes using a finger-mounted pin-array haptic display is one of the major topics of research in haptics. If this can be realized, the operability of objects and immersive feeling in the virtual space will be improved. For now, previous studies showed that shape recognition performance using such a pin-array display was far inferior from the performance in the real world using a real object. We considered that both the density of contact points and coverage areas are essential to improve the recognition performance. However, the size of the actuator that pushes each pin was a constraint, and the previously developed display could not have a large contact density and coverage area. This study proposes a novel design of a finger-mounted pin-array display that works around the constraint. We adopted a pneumatic drive because the pneumatic actuator, or air cylinder, can be a simple structure and can be arranged in a dense array. Our developed finger-mounted display has a higher contact point density and a larger coverage area than any other previously developed devices. It covered more than 4 times larger area on fingerpad with denser pin arrangements. An experiment to evaluate the recognition performance with the device was conducted. Participants discriminated 10 kinds of 2D patterned alphabet shapes with only haptic information. The result showed participants could recognize the ten kinds of 2D patterned shape with 93.8% accuracy. Though our participants' task in the experiment was more difficult, the accuracy was better than previous studies. It suggests the effect of the higher density and the larger size of the coverage.