TactileWalk: Dynamic Electrotactile Patterns for Fingertip-Based Interaction During Walking

Abstract

TactileWalk evaluates dynamic electrotactile patterns on fingertips for wearable navigation. We developed a fingertip stimulation prototype featuring a 10x6 electrode grid driven by an ESP32 microcontroller and high-voltage drivers to enable rapid, independent electrode activation for spatiotemporal pattern rendering. This research compares three dynamic patterns- Single Line, Double Line, and Box-across eight directions presented on the tactile display at the fingertip. Study 1 (stationary) revealed that simple linear patterns were recognized significantly more accurately than complex shapes. Study 2 (walking) confirmed these cues remain robust under movement, where the Double Line pattern yielded the highest accuracy (90.83%). Participants consistently preferred the reinforcing Double Line and found vertical motion more intuitive while walking. We propose design implications for mobile haptics, advocating for simple, spatially redundant patterns to minimize cognitive load during eyes-free navigation.

Figures (5)

• Figure 1: Electrotactile pattern taxonomy for Study 1. The stimulus set includes three fundamental spatial primitives: (A) Single Line, (B) Double Line, and (C) Box patterns. Arrows indicate the dynamic movement patterns applied to each configuration during the study.
• Figure 2: (Top) The fingertip electrotactile prototype set up. This interface consists of a 10×6 electrode grid and intensity control slider. (Center) software interface used to present stimuli and collect participant responses. Clicking 'Start' button starts the stimuli on the fingertip and the participant is required to select a perceived pattern and click 'Next' to confirm. (Bottom) Study setup where a participant experiences the feedback on the fingertip and reports their results
• Figure 3: Study 1 results showing mean accuracy of the perceived pattern (Top) and mean response time (Bottom). Error bars represent standard deviation.
• Figure 4: Setup of the 2nd study with the mobile setup. (Left) The electrotactile grid mounted on the back of the phone. (Right) Study setup showing a participant performing the walking-based pattern recognition task. Participant's mobile device displayed an interface similar to Fig. \ref{['fig:study1_prototype']}(center) to report their responses.
• Figure 5: Study 2 results showing mean accuracy (left) and response time (right) during walking. Error bars represent standard deviation.