A Wearable Skin Stretch Device for Lower Limbs: Investigation of Curvature Effect on Slip

Motion instruction is indispensable for improving skills such as sports and dance. Presenting force and tactile information to humans makes it possible to directly teach motion information; however, existing research for the lower limbs is primarily for walking navigation, since the degree of freedom is only one in navigating directions. In this study, we propose a system that induces leg movement by rotating three end effectors with servomotors. It is possible to induce both translational and rotational motions of the leg by rotating three end effectors. The slip between the end effector and the skin is a significant issue in displaying force. Thus, we aim to examine the effect of the end effector’s curvature on the slip occurrence. In the experiment, the contact area and the shearing force were evaluated when the curvature of the end effector was changed. We confirmed that the effect of the slip could be lessened by increasing the radius of the end effector curvature.