Biological adhesive pads of some reptiles and insects, such as tree frogs and grasshoppers, are covered with planar microstructures and have strong and stable adhesive ability on both wet and dry substrates. These adhesion forces do not mainly come from van-der-Waals force but wet adhesion. In this study, the influence of substrates' surface roughness on the wet adhesion of man-made adhesive pads inspired by tree frog toe pads is investigated experimentally. Biomimetic polydimethylsiloxane adhesive pads with planar hexagon microstructures with a microchannels width of 10 µm are fabricated by combining electroforming with soft lithography. Experiments of wet adhesive force between the pads and sandpaper slices with different average surface roughness are carried out at various preloads. Results show that the rougher surface leads to the decrement of wet adhesion force. It is also observed that if the microcosmic profile height of the substrates is near or less than the width of microchannels in the biomimetic adhesive pads, the microstructures and preloads can increase significantly the wet adhesive force, otherwise the microstructures and preloads do not contribute indistinctively. The experimental results can be explained by analysing the relation between the solid contact area and the area with a liquid bridge.

Burrs are formed in mechanical processes such as cutting and blanking, and can have a number of negative effects, such as reducing product life. Burr removal generally depends on manual treatment methods due to the various shapes and properties of burrs. Deburring is therefore considered a significant issue in terms of achieving efficient production and automation. Electrochemical machining (ECM) is commonly used in the deburring of internal cross holes because of its high efficiency and lack of surface residual stresses. However, in the electrochemical deburring process, stray corrosion may cause loss of machining precision and surface quality. We herein propose a localized electrochemical deburring process using a gelatinous electrolyte to solve the problem of stray corrosion. As the gelatinous electrolyte is in contact with the burr surface without macroscopic liquid flow, electrochemical corrosion is confined to the narrow bounds of the burr. Our results indicate that the proposed process can maintain the original machined precision and surface quality while preventing stray corrosion, which is not possible using traditional ECM.

Electrochemical micromachining can remove electrically conductive materials with the transferring of ions, so that high precision is achievable. A novel method for fabricating high-aspect-ratio microstructures by electrochemical micromachining using vibratile tungsten wire was proposed in this paper. The slight vibration of tungsten wire can improve the machining stability. The relations between the machining accuracy and machining parameters were experimentally studied. Micro groove with the width of 15 μm was machined, and micro sharp-angles structure with aspect ratio of 10 was obtained experimentally.

Biomimetic adhesive pads, which include seta adhesive pads and wet adhesive pads, are compel-ling to be applied for a climbing robot. A novel approach for fabricating biomimetic wet adhesive pads with surface microstructures by combining electroforming process with soft lithography is proposed in this paper. According to the principle of wet adhesive of insects’ pads, the mechanism of wet adhesion is analyzed. Polydimethylsiloxane wet adhesive pads with surface microstructures with the width of 100 μm and height of 25 μm have been obtained experimentally. A series of testing experiments have been carried out to prove that microstructures on the surface of pads fabricated by the proposed technique can effectively improve the wet adhesive ability.

Q235 steel is a low-cost material widely applied in modern industrial constructions. However, electrochemical degradation is the main drawback for its applications in chloride-enriched environments. To address this problem, NiCrAlMo and NiCrAlMo + 2 wt% nano-CeO₂ composite coatings were laser-cladded on Q235 steel substrates. Characterization methods were used to investigate the microstructures, corrosion behaviors, and electrochemical mechanisms of the obtained coatings. The results showed that adding nano-CeO₂ is conductive for removing residual gas pores and for refinement of grains, effectively improving the passive and electrochemical properties of the NiCrAlMo coating in both chloride-enriched solutions. Furthermore, the NiCrAlMoCeO₂ composite coating exhibits a significantly reduced i_corr of 0.4919 µA cm² and an increased resistance ( R_p) of 175,310 Ω cm² in a neutral solution, demonstrating the good anti-corrosion properties for its application in marine engineering structures.