Multiple Remote Vibrotactile Noises Improve Tactile Sensitivity of the Fingertip via Stochastic Resonance

This paper proposes a method to improve the tactile sensitivity of the fingertip by placing multiple vibrators at a remote position away from the fingertip. It is known that a fingertip's tactile sensitivity improves when vibrotactile noise is applied to the fingertip or to a position away from the fingertip, such as the wrist. This is the application of stochastic resonance to the field of haptics. Preliminary experiments in this study have shown that the improvement of a fingertip's tactile sensitivity via remote vibrotactile noise depends on the propagation of the vibration on human skin. From the results of the preliminary experiments, it is expected that the larger the noise reaching the fingertip, the smaller the detectable input. Therefore, we consider that multiple vibrators at a remote position can propagate a larger noise to the fingertip and further improve the fingertip's tactile sensitivity compared to the use of only one vibrator as occurred in a previous study. Finite element analysis was performed so that the noises from multiple vibrators were properly superimposed at the fingertip. To synchronize the arrival of the noises at the fingertip from the multiple vibrators, we determined the positions of the vibrators and the time when each vibrator started generating noise. The results of a subject experiment confirmed that the proposed method significantly improved fingertip sensitivity compared to the case without SR or the case where only one vibrator was used.