More robots… Rough terrain locomotion has mainly relied on rigid body systems, such as crawlers and leg mechanisms. The guys at the Department of Robotics, Ritsumeikan Univ.ersity, Japan are looking at alternative approachs that uses deformation .

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Locomotion mechanisms consisting of rigid body systems have drawbacks: large weight that may cause impact to humans and difficulty in recovery from their overturning. Recently, mechanisms that can recover from their overturning have been studied but these mechanisms tend to be complicated. Recent research on soft actuators such as shape memory alloy (SMA) wires and polymer gel actuators has yielded positive results. Soft actuators have been used to drive leg mechanisms and soft body robots. Locomotion mechanisms consisting of soft actuators can also be light-weight.

Unfortunately, soft actuators still have drawbacks. They tend to generate a small force, and those that generate a large force need either a high driving voltage over 1,000V, making it difficult to build self-supporting robots, or a wet environment. To overcome this problem, they have employed soft actuators to controllably deform a robot body, enabling it to crawl over and jump on rough terrain. Crawling and jumping using deformation can cope with rougher terrain than rigid body systems can. Additionally, soft body deformation reduces the damage in collision with humans.