Abstract
A fish-like aquatic robot, which has a smart-tailfin driven by electric-driven SMA-actuator, is introduced. The tailfin consists of a flexible polypropylene sheet with two fiber-like SMAs pasted on the both surface of the sheet. Control of a displacement of the fin is tried by measuring the change of the electric resistance of SMAs due to their deformation. Outlines of the structure and mechanism of the robot are introduced, and the experimental results by a prototype robot are shown.