A compliant soft-actuator laterotactile display

Humans are extremely adept at eliciting useful information through touch, and the tactile domain has huge potential for handheld and wearable electronic devices. Smart materials may be central to exploiting this potential. The skin is highly sensitive to laterotactile stimulation, where tactile elements move laterally against the skin, and this modality is well suited for wearable devices. Wearable devices should be soft and compliant, in order to move with the user and be comfortable. We present and characterize a laterotactile display using soft and compliant dielectric elastomer actuators. We carry out an initial psychophysical study to determine the absolute sensitivity threshold of laterotactile stimulation, and find that at low frequencies sensitivity is higher than for normal tactile stimulation. Our results suggest that the mechanoreceptors close to the skin surface (SA1, FA1) have improved sensitivity to laterotactile stimulation. We believe our results lay the foundation for a range of new soft robotic human interface devices using smart materials. (paper)