Abstract
The goal of this study is to develop a buoyancy control device for underwater robots based on the hypothesis on the buoyancy control mechanism of sperm whales. This mechanism utilizes volume change caused by phase changes of materials. In this paper, we report a new buoyancy control device that utilizes rubber stretch. Paraffin wax filled in the device was cooled by pettier elements and heated by them and a nichrome wire, resulting in volume change. We conducted experiments and confirmed that the proposed mechanism could increase and decrease its buoyancy. Then, we built a prototype of an underwater robot with the device and confirmed that the robot was able to change its buoyancy continuously.
