Hervé Arribart

Replication of butterfly wing and natural lotus leaf structures by nanoimprint on silica sol-gel films.

An original and low cost method for the fabrication of patterned surfaces bioinspired from butterfly wings and lotus leaves is presented. Silica-based sol-gel films are thermally imprinted from elastomeric molds to produce stable structures with superhydrophobicity values as high as 160 degrees water contact angle. The biomimetic surfaces are demonstrated to be tuned from superhydrophobic to superhydrophilic by annealing between 200 degrees C and 500 degrees C.

Chemists and the school of nature

The term biomimicry first appeared in 1962 as a generic term including both cybernetics and bionics. It referred to all sorts of imitation of one form of life by another one, while the term “bionics”, defined as “an attempt to understand sufficiently well the tricks that nature actually uses to solve her problems”, is closer to the meaning of “biomimicry” as it has been used by materials scientists since the 1980s. Biomimetism is an umbrella covering a variety of research fields ranging from the chemistry of natural products to nanocomposites, via biomaterials and supramolecular chemistry. It is an informal movement and the concept itself is so loose that one might wonder whether biomimetism is more than a slogan forged by chemists in order to hop on the “green” bandwagon. Or could it bring a revolution into chemistry with a profound transformation of its practices? It is too early to judge, but a historical perspective helps to highlight some trends and tendencies.