In this paper, we quantify several spatial capabilities of the human tactile system needed for tactile feedback, or teletaction. Psychophysics experiments measure the amplitude resolution of the human tactile system, the effects of shear stress on grating orientation discrimination, and the effects of viscoelasticity (creep and relaxation) on tactile perception for static touch. The results are used to determine teletaction system design parameters. We find that 10% amplitude resolution is sufficient for a teletaction system with a 2 mm elastic layer and 2 mm tactor spacing.

Teletaction is the transmission of cutaneous information from a remote tactile sensor to an operator's skin, typically the finger tips. Ideally, one would like a realistic sensation of directly touching an object with one's own finger and sense properties such as local shape, hardness, or texture. Teletaction or tactile feedback is one component of haptic feedback, the other component being force or kinesthetic feedback. This paper considers design issues for teletaction systems, particularly sampling density, aliasing, and the limitations of using an array of 1-DOF actuators to approximate a continuous stress distribution on the human finger.