A Design Guide for Manufacturing Deep-Sea Pressure Vessels with SLA 3D Printing

The development and usage of ocean technology are often limited by the cost of the hardware required to observe and explore this harsh and high-pressure environment. Pressure housings, which are used to contain electronics in a dry 1-atmosphere environment while withstanding external pressure underwater, are widely utilized yet expensive components that require specialized design tools and precision manufacturing. The cost and manufacturing time of pressure housings can be significantly reduced through additive manufacturing methods, such as stereolithography (SLA) 3D printing. However, predicting the design failure of 3D-printed pressure housings through Finite Element Analysis (FEA) has proven unreliable and inaccurate due to the poorly understood and often inconsistent material properties of photopolymer resins. This study presents empirical data on the failure pressure of cylindrical and spherical housings across varying thickness to outer diameter ratios and, for cylinders, length to outer diameter ratios. The authors also present a comparison of multiple SLA materials from Formlabs for a cylindrical housing. These results serve as a design guide for those interested in manufacturing their own customizable underwater pressure housings with 3D printing. Furthermore, all test designs and other pressure housings created by the authors are openly accessible on GitHub to promote collaboration and knowledge-sharing amongst a broad community of engineers, scientists, and educators.