Our behavior as a social species is shaped by social interactions mediated by neurobiological and psychological mechanisms, such as our sense of touch. C-tactile afferents (CT) are a population of cutaneous nerves that are hypothesized to play a crucial role in encoding the affiliative and positive aspects of skin-to-skin interactions.

Standard methods of CT stimulation involve controlled light strokes on small areas of the body with varying forces and velocities. To broaden the scope of CT-mediated gentle touch exploration, here we present two novel devices, the MultiTAC and VibroTAC, designed to deliver CT targeted stimulation using light strokes and vibration, respectively.

In a study with 23 participants, tactile stimuli were applied to the forearm at six different speeds, and the resulting pleasantness ratings on a visual analogue scale (VAS) were compared to those from a gold standard approach (the Robotic Tactile Stimulator; RTS).

Our results indicate that brush strokes that move across the skin at CT-preferred velocities, as well as sequential vibration applied on the surface of the skin, elicit positive pleasant responses. In addition, the MultiTAC device was found to be valid for use in psychophysical approaches involving C-Tactile.

The MultiTAC offers mobility and versatility, making it suitable for exploring almost any part of the human body. The VibroTAC is one of the first devices to stimulate individuals using sequential vibrations to produce this type of pleasant response. Both devices encourage the exploration of touch-mediated social interactions and offer new possibilities for research related to C-Tactile and gentle touch.