Frequency-Controlled Slip Speed Perception in a Dual-Array Tactile Display

Abstract

The sensation of tactile slip is ubiquitous to dexterous in-hand manipulation and plays a central role in grip control and surface perception. Replicating these sensations artificially is a valuable tool for increasing embodiment and immersion in robotic teleoperation and virtual reality applications. Existing slip-rendering devices span a wide range of designs, including vibrotactile, belt-, platform-, and tactor-based systems, each involving varying degrees of mechanical complexity. The present device elicits vivid tactile slip illusions through a minimalist architecture of only two independently actuated interleaved pin arrays [1], [2]. When driven in anti-phase, the arrays produce a differential motion mode that reliably evokes the sensation of a surface slipping beneath the finger. Building on this platform, the present work investigates whether vibration frequency can serve as an independent control parameter for perceived slip speed, independent of amplitude. A two-alternative forced-choice psychophysical experiment was conducted with 30 participants. In the motion detection part of the experiment, participants reliably identified the anti-phase stimulus as motion at 70 Hz and 90 Hz (both p < .001), while performance at 50 Hz did not exceed chance, attributed to hardware resonance. In the speed discrimination part of the experiment, participants consistently perceived frequencies above the 70 Hz reference as faster (p < .001 at 80 and 90 Hz), while four participants showed an inverted frequency–speed relationship. These results support frequency variation as a viable encoding strategy for perceived slip speed in dual-array tactile displays.