Design and Evaluation of a Non-Adhesive Wearable Electrotactile Haptic Device for the Palmar Hand Region

This study presents the design and evaluation of a non-adhesive, wearable electrotactile haptic device aimed at delivering tactile feedback to the palmar region of the hand. Unlike traditional adhesive electrode-based devices, the proposed system features a reusable non-adhesive, modular structure with flexible electrode casings and contoured holders to ensure stable electrode-skin contact while preserving finger dexterity. The device employs Transcutaneous Electrical Nerve Stimulation (TENS) to activate mechanoreceptors through targeted stimulation of the median and ulnar nerves. Experimental evaluations with six participants revealed that electrotactile sensations were consistently perceived in the thumb but varied between other fingers depending on the size of the hand and the position of the electrode. Users with dimensions of the hand closely matching the reference design reported a uniform sensation across all fingers, while others required electrode modifications for optimal performance. The results underscore the importance of adaptable electrode configurations to accommodate anatomical differences. This study highlights the potential of non-adhesive electrotactile interfaces for practical applications in haptics and human-computer interaction.