Biomimicry are often at the beginning of the production of certain surfaces with extraordinary properties on a nanometric scale. In particular, surfaces characterized by specific topographies now make it possible to reproduce, for example, the extreme hydrophobicity of the lotus leaf surface, the high adhesion of the gecko’s feet or even the anti-reflective properties of the moth’s eyes.
Researchers from Hubert Curien’s laboratory (Jean Monnet University, CNRS, IOGS) have developed an ultrashort laser irradiation process to transform a flat surface into a “nineteen forest” with the highest aspect ratio ever achieved. The work was recently published in the prestigious journal ‘Advanced Science’. These initial results also open up prospects for transdisciplinary research, especially in the field of biology.
The originality of the work carried out by the team of the “Laser-Matter Interaction” laboratory lies in the experimental two-pulse configuration of the femtosecond laser, which made it possible to obtain a height of nanopoles reaching 100 nanometers at a width of 20 nanometers. Timing of laser beams with polarization control on a nickel single crystal substrate also allows for regular and densely compact distribution of nanostructures formed over large areas.
The method used represents a significant improvement of current laser surface treatment processes. It is indeed located in a hitherto unexplored scientific field, where the combination of light and hydrodynamic effects acts in a coherent and synergistic way on a nanometric scale, which allows the creation of self-organized meta-structures. This work also confirms that ultra-fast laser technology is very promising as a non-contact process capable of rationally and quickly producing complex nanostructures with innovative surface functions.
The obtained results have already attracted the attention of the community of biologists, who see in these results the prospect of improving the antibacterial properties of some materials. In fact, it has previously been shown that the lethal mechanical forces causing the death of bacterial cells require pointed geometries and a very high aspect ratio. This is the case, for example, with the mechano-bactericidal nanostructures of cicada wings, which cause critical damage to the membrane of the microorganisms deposited on them, leading to their death.
“The diameter of most viruses, which is larger than the diameter of our nanopeaks, we may consider opening this work to looking for possible virucidal properties of these nanostructures,” says Anthony Nakhoul, PhD student responsible for the project and co-author of the article.
The research team is also considering possible innovative applications of these results in various areas of metaphotonics, such as optical communications, solar energy, optical light guidance or even imaging and sensor technologies.
This work was carried out with the financial support of the Investissement d’Avenir, EUR MANUTECH-SLEIGHT Programs (Project ANR-17-EURE-0026), coordinated by the University of Lyon and managed by the University of Jean Monnet, and ADEME (IMOTEP Program).
Starring: Anthony Nakhoul, Anton Rudenko, Claire Maurice, Stéphanie Reynaud, Florence Garrelie, Florent Pigeon, Jean-Philippe Colombier.
Enhanced spontaneous formation of nanopeaks with a high aspect ratio on the ultrafast laser irradiated Ni surface. Advanced science (2022).
Read the post: http://doi.org/10.1002/advs.202200761