Robots That Speak and Touch: A Scoping Review Protocol on Verbal and Tactile Modalities for Empathic Human-Robot Interaction

Background: Empathy, widely recognised as vital for well-being – especially in health and care settings – relies on nuanced, multimodal interaction. Expressing empathy often involves both verbal and tactile communication. While robots increasingly express empathy through either language (e.g., via large language models) or touch (e.g., haptic feedback), few systems combine both modalities in a coordinated way. This limits their potential to support emotionally responsive interaction in contexts such as mental health care and paediatrics. Objective: To systematically map and analyse existing robotic systems that combine verbal output (speech/text) and tactile output (e.g., pressure, vibration) for affectively responsive human-robot interaction (HRI). Methods: This protocol follows the PRISMA-ScR framework. We will search multiple databases (Scopus, IEEE Xplore, ACM DL, PubMed, Web of Science) and grey literature. Eligible systems must produce both verbal and tactile output, support social or affective interaction, and include implementation details. Screening will focus on robotic systems, not individual studies. Extracted data will cover integration strategies, autonomy, and context of use, with findings synthesised thematically to highlight design patterns and gaps.