TactTongue: Prototyping ElectroTactile Stimulations on the Tongue

The tongue is a remarkable human organ with a high concentration of taste receptors and an exceptional ability to sense touch. This work uses electro-tactile stimulation to explore the intricate interplay between tactile perception and taste rendering on the tongue. To facilitate this exploration, we utilized a flexible, high-resolution electro-tactile prototyping platform that can be administered in the mouth. We have created a design tool that abstracts users from the low-level stimulation parameters, enabling them to focus on higher-level design objectives. Through this platform, we present the results of three studies. Our first study evaluates the design tool's qualitative and formative aspects. In contrast, the second study measures the qualitative attributes of the sensations produced by our device, including tactile sensations and taste. In the third study, we demonstrate the ability of our device to sense touch input through the tongue when placed on the hard palate region in the mouth. Finally, we present a range of application demonstrators that span diverse domains, including accessibility, medical surgeries, and extended reality. These demonstrators showcase the versatility and potential of our platform, highlighting its ability to enable researchers and practitioners to explore new ways of leveraging the tongue's unique capabilities. Overall, this work presents new opportunities to deploy tongue interfaces and has broad implications for designing interfaces that incorporate the tongue as a sensory organ.