Soft and Noiseless Actuator Technology Using Metal Hydride Alloys to Support Personal Physical Activity

In an aging society with a declining birth rate, there is an increased need for home-based rehabilitation systems and human-centered robots for healthcare services. In particular, elderly patients who are required to lie in a reclined position due to stroke or bone fracture may suffer from disuse syndromes, such as bedsores, joint contracture and muscular atrophy (Bortz, 1984). It is difficult for these elderly patients to actively exercise for preventive rehabilitation. Thus, to manage these disuse syndromes, rehabilitation equipment and assistive devices, such as bedside apparatuses for the continuous exercise of joints and power assistance devices for standing and transfer hoists, must be developed. This equipment demands powerful and soft actuators in addition to human muscles (Bicchi & Tonietti, 2004).