Ultraviolet patterns of flowers revealed in polymer replica - caused by surface architecture.

Angiosperms and their pollinators are adapted in a close co-evolution. For both the plants and pollinators, the functioning of the visual signaling system is highly relevant for survival. As the frequency range of visual perception in many insects extends into the ultraviolet (UV) region, UV-patterns of plants play an important role in the flower-pollinator interaction.

Hierarchically structured superhydrophobic flowers with low hysteresis of the wild pansy (Viola tricolor) - new design principles for biomimetic materials.

Hierarchically structured flower leaves (petals) of many plants are superhydrophobic, but water droplets do not roll-off when the surfaces are tilted. On such surfaces water droplets are in the "Cassie impregnating wetting state", which is also known as the "petal effect". By analyzing the petal surfaces of different species, we discovered interesting new wetting characteristics of the surface of the flower of the wild pansy (Viola tricolor).

Droplets on superhydrophobic surfaces: visualization of the contact area by cryo-scanning electron microscopy.

The contact area between liquids and solid surfaces plays the crucial role in the wetting and self-cleaning properties of surfaces. In this study, we have developed a cryo-preparation method to visualize the contact area between liquids and superhydrophobic biological surfaces by scanning electron microscopy. Aqueous liquids that do not crystallize during freezing, such as glycerol and phosphoric acid, were used.

Biomimetic replicas: Transfer of complex architectures with different optical properties from plant surfaces onto technical materials.

Plant surfaces are characterized by a high diversity of structures which determine their optical properties, such as shiny, gleaming, silky, matt or iridescent. Replicas with different optical properties have been generated by using plant surfaces as templates and an improved replica technique. The technique allows the replication of complex surface structures with overhangs, cavities, and fragile or soft structures in a fast and cost-efficient way.

A fast, precise and low-cost replication technique for nano- and high-aspect-ratio structures of biological and artificial surfaces.

Biological surfaces are multifunctional interfaces between the organisms and their environment. Properties such as the wettability and adhesion of particles are linked to the micro- and nanostructures of their surfaces. In this study, we used plant and artificial surfaces covered with wax crystals to develop a low-cost replication technique with high resolution.