Magnetic levitation detection towards optimization of manufacturing deep-sea elastomers with extreme micro-bubble defects

Abstract

Soft robots offer unique advantages in deep-sea exploration, but bubbles in their elastomers degrade mechanical properties under extreme pressure, rendering their manufacturing process highly demanding. Here, to facilitate the optimization of deep-sea elastomer manufacturing, we propose a detection method to address challenges in non-destructively detecting internal extreme micro-bubbles using magnetic levitation (Maglev), with a sensitivity of up to 1069.04 mm [g cm³]⁻¹. This method establishes a mathematical model that relates levitation attitude (height and angle) to density and volume moments, quantifying bubble rates and distribution. Additionally, validation of pressure resistance is conducted at 1000 atmospheres (atm) (equivalent to 10,000 m deep in the sea). The results indicate that the volumetric shrinkage of silicone rubber (SR) at 1000 atm can drop from 8.45 % to 3.26 % by reducing the bubble rate, a parameter that can be adjusted by optimizing the defoaming time and can be detected quickly (< 30 s) by Maglev device. This method’s result is not affected by various factors such as shape, size, and manufacturing process, demonstrating its wide applicability. This study verifies the reliability, accuracy, cost-effectiveness, and universality of Maglev-assisted optimization manufacturing deep-sea elastomers, and provides guidance for the development of pressure-resistant soft robots for extreme environment exploration.