Soft Actuation and Compliant Mechanisms in Humanoid Robots

Purpose of Review We aimed to reveal the impact of soft robotics, which has developed in the last decade, on humanoid robotics research. Although humanoid robots are usually classified as hard robotics, softness should be integrated because soft materials and mechanisms are used extensively in the human body. Recent Findings In recent years, new soft actuators based on hybrid approaches, such as the combination of electricity and fluid, have emerged. Physically compliant robotic systems that are safe and robust are needed to take on higher-risk tasks and to tolerate large numbers of trials in the process of machine learning. Summary Emerging soft actuators are enabling humanoid robots to achieve rapid movements with physical impacts. Efforts to integrate soft robotics and humanoid robots are still on their way. A potential direction for humanoid robots is their application to physical human-robot interaction, where further exploitation of softness is expected.