RelicTouch: Exploring Fingertip Vibrotactile Feedback for Image Interpretation

Vibrotactile feedback is often used to simulate material properties on interactive surfaces, but less is known about how it can help users interpret visual differences during touchscreen exploration. We present RelicTouch, a finger-worn system that converts image-derived features into movement-contingent vibration. Study 1 was a controlled within-subject experiment (n=20) examining how vibration intensity, stripe spacing, and finger configuration affected haptic--visual congruence and subjective clarity. Study 2 was an exploratory qualitative study with eight domain experts examining how users interpreted cues generated from luminance and edge variation during continuous image exploration. Results suggest that cue legibility was associated with distinguishable signal changes, movement-based comparison, and visual or task context. Single-finger exploration yielded higher subjective ratings, whereas multi-finger feedback showed possible value for coarse comparison across separated features. These findings provide initial design implications for vibrotactile image exploration beyond material-simulation-oriented rendering.