Spatial low pass filters for pin actuated tactile displays

A common tactile display design uses an array of mechanical pins covered by a rubber layer which acts as a spatial low pass filter. To characterize the perceptual relationship between this rubber layer and shape rendering, we conducted psychophysical experiments to examine the perception of a vertical line stimulus felt using rubber covers of varying thickness and stiffness. We found no significant change in perception for rubber thicknesses ranging from 1.5-3.0 mm and for stiffnesses ranging from 45-200 kN/m².