Enhancing Air Retention by Biomimicking Salvinia molesta Structures

The air-retaining property of the hydrophobic surface can be widely employed in many applications. This study is carried out to enhance this property by biomimicking the structure of Salvinia molesta floating leaves, which features hydrophilic patches on a superhydrophobic structure. Different from the existing lotus structure, in this study, the theoretical models and equations governing the contact and sliding angles, and contact line density of the salvinia structure were developed. The Marangoni effect was re-examined and modified to consider the characteristic of the salvinia structure. In addition, a novel process was proposed to fabricate the salvinia and lotus structures, which were designed using mathematical models and numerical simulation results. Both structures were tested to verify the theoretical models and derived governing equations. The results indicate that the air-retaining property was greatly enhanced using the salvinia structure compared with the lotus one.