Design and Psychophysical Evaluation of Pneumatic Tactile Display

This paper presents a novel pneumatic tactile display. The air-jet display forms 5 by 5 arrays and features air nozzles with an external diameter of 2.4 mm and internal diameter of 1.5 mm. In comparison with other tactile displays such as vibrotactile, electrotactile displays there is little concrete psychophysical data relating to pneumatic displays. This paper addresses this challenge, and presents brief psychophysical studies examining localization rate, the two point threshold, stimulus intensity and the temporal threshold of cues produced by pneumatic air jets. Two groups of subjects were used in these studies, subsequently termed groups A and B. Both were comprised of eight participants. In the case of localization study we obtained 58.13% and 85.9% of localization rates each for dense display and sparse display. Two-point threshold test showed the length of gap between two air-jet stimuli which subjects can detect. However, it was formidable to find out precise temporal resolution of the proposed pneumatic tactile display owing to the limited capability of the pneumatic valves. Lastly, the results of stimulus intensity study suggest that by varying the size of a pneumatically created tactile stimulus, we can effectively vary its perceived magnitude