Comparing soft robotic affective touch to human and brush affective touch

Affective touch is important for maintaining emotional bonds and providing comfort. In this pilot study, we developed a silicone pneumatic soft robotic haptic device (S-CAT) to provide affective touch and compared its performance with commonly used brush and human affective touch. The S-CAT device simulates the attributes of CT-optimal affective touch in terms of velocity, temperature and force. In 22 participants we administered touch on their forearm from the S-CAT device (robot), a human hand and a soft brush at 6cm/s (CT-optimal speed) and 36cm/s (non-CT optimal speed). We collected subjective ratings on pleasantness and intensity, as well as electroencephalography (EEG) responses. The results showed that pleasantness and intensity ratings depend on velocity of the touch. Moreover, S-CAT touch delivered at these different velocities elicits similar subjective ratings to using a human hand or brush. Findings point to the potential for soft robotic haptic devices to modulate subjective and electrophysiological response in a similar way to more natural, human touch.