A soft robotic tongue to develop solutions to manage swallowing disorders

The development of novel texture adaptations for the management of swallowing disorders could be accelerated if reliable in vitro tests were made available. This study addresses some of the limitations of swallowing in vitro models, by introducing a soft robotic actuator inspired by the tongue. The wettability of the soft-robotic actuator was engineered to achieve physiologically relevant contact angles to allow comparing dry and lubricated conditions. The actuator design and the control algorithm are designed to offer flexibility in the swallowing patterns to consider different scenarios, including poor lingual coordination. In vitro swallowing tests with shear thinning liquids were performed as a proof of concept and showed physiologically relevant oral transit time, bolus velocity and palatal pressure. Both the bolus rheology and the coordination of the peristaltic contractions influenced the temporal evolution of the bolus velocity and the bolus transit time. This novel soft robotic tongue, its integration in an in vitro oral cavity and its flexible control can therefore contribute to developing better solutions to manage swallowing disorders.