Development of Thin Vibration Sheets Using a Shape Memory Alloy Actuator for the Tactile Feedback of Myoelectric Prosthetic hands

Because the current myoelectric prosthetic hand does not have a tactile function, the user must always check the condition of the prosthetic hand. Various studies on sensory feedback have been conducted to address this problem, but several devices used in them cannot be integrated with artificial limbs, and wearing the devices is a burden on the user. To solve this problem, we developed thin vibration stimulation sheets using shape memory alloy (SMA) actuators. We then conducted an experiment on the effect of the change in shape at the contact part between the sheet and the skin on perception and confirmed that it would be easier to perceive vibration when the skin was deformed in a wider range. In addition, we investigated the number of distinguishable stimulus intensity levels and identification of stimulus positions. According to the results, the stimulus presented by the developed vibration sheet could be identified in three stages without learning about the stimulus, and the stimulation position by the vibration sheet could be identified with the same or higher accuracy as that of the disk-type vibration motor used in the existing research, although the accuracy decreased when vibrations were presented simultaneously.