In this research, the anisotropic superhydrophobic surface is prepared on a stainless steel surface by laser etching, and the drag reduction property of the anisotropic surface is studied by a self-designed solid−liquid interface friction test device. Periodic arrangement structures of quadrate scales with oblique grooves are obtained on a stainless steel surface by a laser. After modification by fluoride, the surface shows superhydrophobicity and anisotropic adhesive property. Here, the inclined direction of grooves and the inverse direction are defined as RO and OR, respectively. By changing the inclination of the grooves, a surface is obtained with a contact angle of 160°and a rolling angle difference of 6°along the RO and inverse RO direction. It is verified by numerical simulation and experiment that the subjected force of water droplets on the surface is different along the RO and inverse RO direction. Furthermore, the as-prepared surface has different drag reduction effects along the two directions. With the increase of velocity, the drag reduction effect of the superhydrophobic surface decreases against the RO direction, while the drag reduction effect along the RO direction is almost unchanged. We believe the anisotropic surface will be helpful in novel microfluid devices and shipping transportation.

Inspired by the bionic fish scale surfaces containing micro/nanostructured arrays, herein, the applications of lubricant‐impregnated anisotropic slippery surfaces (LIASSs) using laser ablation of aluminum–magnesium alloys are proposed. Different hydrophobic properties are presented on the LIASSs along the parallel direction and the reverse direction defined as directions A and B of bionic fish scale micro/nanostructures. A self‐assembled solid–liquid interface friction test device is set up to demonstrate the drag reduction property of LIASSs. The drag reduction ratios are found to be 51.09% and 44.88% along directions A and B, respectively. With the increase in the velocity, the drag reduction ratios of LIASSs can also be kept near 50%. Simulation models are established to study the drag reduction mechanism of LIASSs in laminar flows. Liquid–liquid repellency has a lubricating effect that can increase mobility and reduce viscous resistance. In this way, it improves the fluidity of the liquid and reduces drag. The drag reduction ratio in direction A is superior to that in direction B for the same flow velocity. The results of the simulation are consistent with the experiments results. LIASSs represents an effective strategy to drag reduction and reducing energy consumption in liquid directional transport and marine vessels.

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A novel method to fabricate the superhydrophobic surface with a 3D flower-like micro-nanostructure on the steel foil was presented here. The surface shows good drag reduction effect and has numerous technical applications in drag reduction field.