Mimicking the hierarchical surface topography and superhydrophobicity of the lotus leaf on magnesium alloy AZ31

Surface modification of biodegradable magnesium alloys to control their degradation rate and give optimum biocompatibility is essential for the application of these materials in medicine. In this letter, chemical etching coupled with the deposition of a biocompatible siloxane coating has been employed to produce a biomimetic superhydrophobic magnesium alloy surface with excellent stability in aqueous solution. Characterization of the topography of the superhydrophobic surface show that these surfaces have a hierarchical surface structure composed of microscale spherical features and nanoscale rod-like structures that closely mimic the surface structure of the lotus leaf.