The purpose of this research is to reduce the weight of the brake system of vehicles and to increase braking performance and its durability and to shorten the stopping distance. The plans for light-weight vehicles are to develop light weight material itself which possesses superior properties and another way is to improve the manufacturing method of materials which have the better mechanical properties. And the materials used for this are aluminum alloy, magnesium alloy, titan alloy, steel, other metals, plastic, ceramic materials etc. In this research, aluminum is used for the main body of the break to reduce the weight of the brake and cast iron(SCM4), stainless steel(SUS304) and titan alloy(Ti Gr2) are used for the outer ring shape plate and assembled with bolts. Dynamometer test are braking performed on the brake disc. Based on the test results, stainless steel(SUS304) is optimized for the light-weight brake disc.

Recently, soft robots using soft materials are presented. Thanks to soft materials, soft robots have flexible, highly-stretchable or adaptable features. However, due to the flexibility of soft material, it is hard for soft robots to control accurately or perform high force. To deal with these limitations, variable stiffness technology, which enables the stiffness control of structure, has been developed. In this research, a dual-stiffness structure that is actuated by the assembly of two flexible structures are presented. Each flexible structure consists of flexible film part and rigid parts placed at regular intervals. The flexibility of film between rigid parts allows each structure to move softly. On the other hand, by combining two structures rigid part of each part constrain the degrees of freedom of the other side part. And this causes the stiffness of whole structure to be increased. This paper will cover concepts, design, analysis and experiments of this structure.