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

• Anna J. Schulte,
• Damian M. Droste,
• Kerstin Koch and
• Wilhelm Barthlott

Beilstein J. Nanotechnol. 2011, 2, 228–236, doi:10.3762/bjnano.2.27

• superhydrophobic, low adhesive surface design, which combines the hierarchical structuring of petals with a wetting behavior similar to that of the lotus leaf. Keywords: anti-adhesive; petal effect; petal structures; polymer replication; superhydrophobic; Introduction Plant surfaces provide a large diversity of

• “petal effect” and are anti-adhesive for water droplets. It is well known that hierarchical surface architecture represents optimized structures for superhydrophobic surfaces [11][33][34][35][36]. Based on the data presented here, we can describe two main superhydrophobic surface architectures for plant

• nanocrystals the surface structures of Viola could be qualified, for example, for large area foil imprinting processes. Thus, a new surface design for the development of superhydrophobic, water repellent biomimetic materials is presented. Experimental Plant material The upper surface (adaxial) sides of the

Sorting of droplets by migration on structured surfaces

• Wilfried Konrad and
• Anita Roth-Nebelsick

Beilstein J. Nanotechnol. 2011, 2, 215–221, doi:10.3762/bjnano.2.25

• ]. Plant surfaces are also known to develop a huge variety of patterns on different length scales [11]. A prominent example are the leaf wax structures leading to superhydrophobicity and the Lotus-effect [12]. Larger structures are also common, e.g., trichomes (leaf hairs) or wart-like structures. Stomata

Functional morphology, biomechanics and biomimetic potential of stem–branch connections in Dracaena reflexa and Freycinetia insignis

• Tom Masselter,
• Sandra Eckert and
• Thomas Speck

Beilstein J. Nanotechnol. 2011, 2, 173–185, doi:10.3762/bjnano.2.21

• Tom Masselter Sandra Eckert Thomas Speck Plant Biomechanics Group Freiburg, Botanic Garden, Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104 Freiburg, Germany Competence Network Biomimetics and Bionics Competence Network BIOKON e.V 10.3762/bjnano.2.21 Abstract Branching in

• using solutions inspired by plant ramifications, e.g., in automotive and aerospace engineering, architecture, sports equipment and prosthetic manufacturing. Keywords: Biomimetics; branching; Dracaena reflexa; Freycinetia insignis; monocotyledons; Introduction One of the most conspicuous features of

• branch occurs mainly in relatively young, possibly not fully lignified branches (see below). Failure in the stem results in longitudinal cracks which very quickly reach a critical length and lead to failure of the main stem. This failure mode is the most disadvantageous one for the plant and can be

Superhydrophobicity in perfection: the outstanding properties of the lotus leaf

• Hans J. Ensikat,
• Petra Ditsche-Kuru,
• Christoph Neinhuis and
• Wilhelm Barthlott

Beilstein J. Nanotechnol. 2011, 2, 152–161, doi:10.3762/bjnano.2.19

• lower epidermis. The lotus plant has successfully developed an excellent protection for this delicate epistomatic surface of its leaves. Keywords: epicuticular wax; leaf surface; Lotus effect; papillae; water repellency; Introduction Since the introduction of the ‘Lotus concept’ in 1992 [1][2], the

• lotus leaf became the archetype for superhydrophobicity and self-cleaning properties of plant surfaces and a model for technical analogues [3][4] . Lotus (Nelumbo nucifera) is a semi-aquatic plant and develops peltate leaves up to 30 cm in diameter with remarkable water repellency. As an adaptation to

• been known for a long time that plant surfaces covered with epicuticular wax crystals are water repellent, and that this feature is enhanced when the epidermis has additional structures such as papillae or hairs [5][6]. Neinhuis and Barthlott (1997) [7] presented an overview of more than 200 species

Biomimetics inspired surfaces for drag reduction and oleophobicity/philicity

• Bharat Bhushan

Beilstein J. Nanotechnol. 2011, 2, 66–84, doi:10.3762/bjnano.2.9

• animals, and seashells with properties of commercial interest. Certain plant leaves, such as lotus (Nelumbo nucifera) leaves, are known to be superhydrophobic and self-cleaning due to the hierarchical surface roughness and presence of a wax layer. In addition to a self-cleaning effect, these surfaces with

• the negative replica. To generate several replicas the second step of replication was repeated twenty times for each surface type. Nanostructures were created by self-assembly of plant wax deposited by thermal evaporation [12][13]. Tubule forming wax, which was isolated from a leaf of Nelumbo nucifera

• hydrophobicity using a dynamic AFM method [16][33]. Data on one hydrophilic, one hydrophobic, and one superhydrophobic surface are presented in Table 2. Mica was taken as the hydrophilic surface. Hydrophobic and superhydrophobic surfaces were fabricated by deposition of evaporated plant wax on smooth epoxy