Abstract
The goal of this study is to build a buoyancy control device utilizing volume change of material induced by the phase transition between the liquid and the solid states. The high pressure in the deep sea must vary such material characteristics as the volume change, the melting point, and the amount of heat necessary for achieving the phase transition. First, we investigated those characteristics of paraffin wax based on the values in literatures and established a method to estimate the melting point and the volume in each phase under arbitrary pressures. We then calculated the amount of heat necessary for achieving the phase transition between the liquid and the solid states, and found that our system is suitable under the high pressure of approximately 100 MPa. We conducted experiments under the pressures of less than 1 MPa and found that they do not vary the volume change.
