Distributed Tactile Display with Dual Array Design

It is well-accepted that designing and manufacturing distributed tactile displays is hard owing to difficulties associated with packing many strong actuators in a small space. We explored a new design for such displays by reducing the number of independently actuated degrees of freedom while preserving the ability to decorrelate the signals applied to small regions of the fingertip skin inside the contact area. The device comprised two independently actuated tactile arrays so the degree of correlation of the waveforms stimulating those small regions could be globally controlled. We show that for periodic signals, the degree of correlation between the displacement of the two arrays was equivalent to setting the phase relationship between the displacements or the arrays or the mix of common and differential modes motions. We found that anti-correlating the displacements of the arrays significantly increased the subjective perceived intensity for the same displacement. We discussed the factors that could explain this finding.