1508 Application of a Hybrid Power-Supply System Composed of a Passive-type Polymer Electrolyte Fuel Cell and Capacitors to a Fish Robot

Abstract

In order to imitate high-efficiency propulsion by a fish tail under water, the authors made a fish robot, which was assembled from a flexible rubber-sheet body (with a tail) and muscle-like six actuators each of which was composed of a small DC motor and a thin piece of flexible string, Electric power was fed to each motor intermittently in a programmed sequence by a hybrid power-supply system composed of a hydrogen-fueled passive-type polymer electrolyte fuel cell, capacitors and a PWM controller. It has been shown that the fish robot can swim like a fish under water when the actuators are operated in an appropriate sequence. It has been found that the capacitors in this power-supply system are requisite for the actuators, because the load on them varies largely when the fish robot swings its body and tail strongly under water.