Development of active self-melting bolt and its application to self-healing structure

Abstract

This paper illustrates the development of active self-melting bolt aiming at self-healing tendon-driven robot with high-load endurance. Recent pioneering research has explored several methods for applying self-healing principles for robotics. For example, exploiting reversible crosslinking bonds are a major approach. They enable conventional robots to gain selfrepairing capability from micro damages such as stubs and so on. However, providing a healing module with large load endurance and autonomous healing capability is yet a challenging task. Then, we categorized design challenges to construct such a module. In addition, we introduced some alternatives to overcome the problems. First, we formulated fracture and healing energy ratio to select proper material for active healing structure. The measure leads the authors to the statement that a low melting point alloy is a powerful alternative. Next, the authors insist that bolted joint structure is a candidate for self-healing module with high-load endurance. Finally, we validated the feasibility of the module with tensile tests using motor-driven tendon unit that has been developed by our group. The result showed that proposed structure had healing capability in spite of its low healing ratio. In summary, the paper presents design, manufacturing method and validation for active self-melting bolt.