Millimeter-Scale Hydrophilic/Hydrophobic Striped Surfaces for Air Layer Retention and Drag Reduction in Diving Suits

Traditional fully hydrophobic diving suits have limitations in reducing drag and improving speed, primarily due to the formation of an unstable air layer. To address this issue, we propose a millimeter-scale hydrophilic/hydrophobic striped surface design aimed at maintaining a stable air layer and achieving significant drag reduction. By strategically arranging alternating hydrophilic/hydrophobic regions in the critical areas of the diving suit, we first validated the feasibility of this method through preliminary simulations using the CFX simulation software. Subsequently, we demonstrated through comparative experiments that this composite surface maintains an air layer more effectively than do uniformly hydrophilic or hydrophobic surfaces under hydrodynamic conditions. Finally, a mechanistic model was established to elucidate the mechanism behind the maintenance of the air layer on the composite surface and to derive the critical flow velocity required for the formation of the air layer. The results indicate that the hydrophilic/hydrophobic stripe design extends the air layer retention time, providing a foundational framework for optimizing surfaces in underwater applications and offering new insights into designing high-performance diving suits.