Fabrication of a fish-like underwater robot with flexible plastic film body

A portable underwater robot that has a high pressure resistance is required for easy observations in wide area. In this manuscript, we discuss the fabrication and design of a fish-like underwater robot that the outer body is composed by a flexible thin plastic film. Force generated by the differential pressure between inside and outside of the robot is zero due to the flexibility. Therefore, the plastic film of the robot does not ideally break under high pressurized environment. The entire body of the robot is fabricated by a vacuum packaging machine. We call this fabrication robot packaging. The design guide of our fish-like robot depends on the density of insulating fluid containing within the body. Even the fluid is lighter or heavier than water, we can construct the fish-like robot that is at neutral buoyancy