Abstract: Superhydrophobic surface with high adhesive force has attracted great interest in recent years. An intriguing example is the red rose petals, which is famous with its “petal effect” (i.e. the water droplet adhesion effect) and its novel hierarchical micro-/nano- structure. In this article, the surface adhesive effect was characterized by the high-sensitivity microelectromechanical balance system, and the effects of micro- and nanostructure on the adhesive property of rose petals was investigated. The morphology of obverse and reverse surface of fresh and dry rose petals were observed by environmental scanning electron microscope (ESEM), and the wettability was characterized by the apparent contact angle. The experimental results show that surface hydrophobicity can be enhanced by the micro-scaled structure and the high adhesive force is mainly caused by the nano-scaled structure. It is believed that this work will provide us a new avenue to further understand the wettablilty of solid surface, and design novel microfluidic devices in a wide range of applications, such as many localized chemical or biological reactions, traced analysis, and in situ detection.

Key words: Rose Petal, Surface adhesive force, Micro-structure, Nano-structure