Application of FFP-actuators to legged locomotion robots

This paper describes an application of flexible flat plate (FFP) actuators (consisting of shape memory alloy (SMA) and polyethylene plate) to some legged locomotion robots. A key feature is that the legged locomotion robots developed in this paper have no joints. In other words, the FFP actuators that become the robot legs (links) can directly generate power by their deflections. In addition, the assembly time of the FFP actuators is short due to their simple structure. After investigating the fundamental properties of the FFP actuators, we propose ten types of FFP-actuators that are available for assembling a wide variety of legged locomotion robots. Two-legged and four-legged locomotion robots developed in this paper realize walking by transferring the elastic potential energy (generated by deflections of the FFP actuators) to kinematic energy. We demonstrate that the leg displacement can be controlled by adjusting the deflection of the FFP actuators with simple ON-OFF signals.