Design and Performance Study for Electrothermally Deep-Sea Drive Microunits Using a Paraffin Phase Change Material

Abstract

Considering the further exploration of the ocean, the requirements for deep-sea operation equipment have increased. Many problems existing in the widely used deep-sea hydraulic system have become increasingly prominent. Compared with the traditional deep-sea hydraulic system, actuators using a paraffin phase change material (PCM) have incomparable advantages, including lightweight structure, low energy consumption, high adaptability to the deep sea, and good biocompatibility. Thus, a deep-sea drive microunit (DDM) based on paraffin PCM is proposed in this paper. The device adopts a flexible shell, adapting to the high-pressure environment of the deep-sea based on the principle of pressure compensation. The device realizes the output of displacement and force through the electrothermal drive, which can be used as actuator or power source of other underwater operation equipment. The microunit successfully completes the functional verification experiments in air, shallow water, and hydrostatic pressure of 110 MPa. In accordance with experimental results, a reasonable control curve is fitted, highlighting its potential application in deep-sea micro electro mechanical systems, especially in underwater soft robot.

Lightweight Robotic Joint with Thermally Activated Paraffin Actuator in the Deep Sea

“…By inputting heat through internal heating wires, the paraffin material undergoes phase change, thereby changing the overall density to achieve buoyancy regulation. NING et al designed a deep-sea micro-paraffin phase change actuator [19], which is enclosed by a flexible shell to achieve pressure adaptation. Internal heating devices are used to heat the paraffin to induce phase change and generate a volume increment.…”