Involuntary Expression of Embodied Robot Adopting Goose Bumps

In this paper, we propose an involuntary expression of embodied robots by adopting goose bumps. The goose bumps are caused by not only external stimuli such as cold temperature but also the internal state of the robot such as fear. For more natural anthropomorphism, the combination of involuntary and voluntary expressions should enable realistic animacy and life-like agency. The bumps on the robot's skin are generated by changing lengths of thin rods from each hole. The lengths are controlled by a servo motor which pulls nylon strings connected to the base of thin rods.