Development of a mechanical element that changes the shape and rigidity by vacuum pressure

Abstract

The passive mechanical element that can change the stiffness by using particle jamming has been used for soft robots. The mechanical element can keep the shape by decreasing the internal air pressure, however, is not able to transform the shape by itself. Therefore, it has been used in combination with other actuators to transform the shape actively for the use of robots, which increases the complexity of the system. In this study, we developed a novel mechanical element that contains sponges inside the conventional mechanical element. Evacuating the inside air of the element increases the rigidity, same as the conventional one. At the same time, it compresses the sponges and transforms the shape of the element so that it can wrap the element around an object automatically. This novel mechanical element can be used for fixing or grasping objects or a body. The element requires only a vacuum pressure source; therefore, the system is simpler than conventional robots. This paper firstly shows the structure of the mechanical element and the optimization method from the viewpoint of deformability. Secondly, this paper shows the ability of wrapping various objects and that the contact pressure was constant regardless of the shape of the object. Finally, this paper discusses future applications and problems of the element.

Keywords

• particle jamming
• variable stiffness
• vacuum
• transformation
• machine element