Bioinspired Antagonist-agonist Artificial Muscles for Humanoid Eyeball Motions

Natural eyeball motions in humanoid robots can contribute to friendly communication, thus improving the human-robot interaction. In this paper, we develop antagonist-agonist artificial muscles for humanoid eyeball motions, by using dielectric elastomer actuators (DEAs). Inspired by human eyeballs, the artificial muscles consist of two pairs of DEA: one pair for the horizontal motion, and the other for the vertical motion. The fabrication time of actuators can be significantly decreased due to their simple structure. The antagonist-agonist actuator outperforms the dielectric elastomer minimum energy structure in terms of actuation displacement and response time. We conduct experiments in a lifesize human face model. The experiments demonstrate the capability of antagonist-agonist artificial muscles to mimic eyeball motions in the horizontal, vertical, and diagonal directions. Future work includes modeling and control of artificial muscles for optimal performance of various humanoid eyeball motions.