A New Type of Jellyfish-Like Microrobot

This paper presents a new prototype model of an underwater jellyfish-like microrobot utilizing shape memory alloy (SMA) and ionic conducting polymer film (ICPF) as the actuators to realize swimming motion. The overall size of the microrobot is about 75 mm in length, 55 mm in diameter, and the weight is about 6.5 g. The jellyfish-like microrobot has four tentacles. Each of them is composed with a bindiny mechanism and one piece of ICPF actuator. Each tentacle can cooperate with a SMA actuator to increase its movement range and provides more propulsion. The SMA electrified makes the internal volume shrink and the water or other aqueous medium inside the microrobot is driven backwards, thus propulsion force is formed. The moving speed and direction of the microrobot can be controlled by changing the frequency of input voltage on every SMA and ICPF actuator. The four tentacles can collaborate to realize 3 DOF movements. Experiment has been designed and fabricated to study the prototype of Jellyfish and the results indicate that the coordinated-control of SMA and ICPF actuator can provide a large propulsion force.