形状記憶合金とジャミング転移現象を用いた可変剛性リンクの特性評価

抄録

In this study, we evaluated a variable-stiffness and deformable link using shape-memory alloys (SMAs) and the jamming transition phenomenon. For the SMA, the austenite and martensite structures are stable at high and low temperatures, respectively. When an SMA is heated, it transforms from the martensite to the austenite phase and recovers its original shape. During the cooling process, it transforms to revert to the martensite phase. During each heating and cooling cycle, the transformation starts when it reaches the austenite-start temperature and the martensite-start temperature. The stiffness of SMA is high at the austenitic phase and low at the martensite phase. The jamming transition phenomenon for granular material has been widely used as a method to change the stiffness of robots. This phenomenon is the change from fluid-like to solid-like conditions by removing air from a space containing particles. In our previous study, we exploited the characteristics of SMAs and the jamming transition phenomenon to develop robot components with variable stiffness and sensitivity. In this study, we evaluated the variable-stiffness and shape-fixity properties through the experiments using the prototype link.