A multifunctional underwater microrobot for mother-son underwater robot system

In past few years, various underwater microrobots have been developed with the micromachining technology, development of smart actuators and biomimetic applications. Most of them possess the attributes of flexibility and compact structure. However, their endurances, moving speeds, and load capacities for power supplies and sensors are limited for the small sizes. So, these microrobots are not suitable for the real-world applications. To solve these problems, we proposed a mother-son robot system, which included several microrobots as sons and a newly designed amphibious spherical robot as the mother. The mother robot was actuated by four water-jet propellers and eight servomotors, capable of providing a stable high speed and carrying the microrobots to a desired target location where tasks were to be performed. To implement the mother-son robot system, we proposed a multifunctional underwater microrobot and developed the prototype by using ionic polymer metal composite (IPMC) actuators. The microrobot could perform walking, rotating, grasping, floating, and swimming motions with the compact structure. Then we evaluated its moving speeds in the water tank. At last, we carried out the releasing experiment to demonstrate the feasibility of the mother-son robot system.