In an interdisciplinary collaboration between computational engineers and physicists from the University of Luxembourg, published in Nature Communications, a method combining quantum and continuum mechanics has been developed and it was shown to lead to a novel discovery of emergent long-range adhesive interactions for atomically-thin layers on top of surfaces.
Adhesive interactions
Adhesion is a universal phenomenon employed in a wide range of natural and industrial processes. The behaviour of stretchable and transparent electronics, energy devices, sensors, nanocomposites, and biomembranes critically depends on adhesive interactions between different components in these systems. Even the highly contagious nature of the novel coronavirus, which causes the COVID-19 disease, has been associated to the strong adhesion of its spike surface proteins to receptors on the human cell membrane [1,2].
One of the pressing and currently unsolved scientific challenges is to understand and control adhesive interactions between materials of arbitrary complexity. At the engineering scale, mechanical models are generally used to describe systems with complex geometries. On the opposite atomic scale, quantum-mechanical models are used to calculate interatomic interactions that lead to adhesive behaviour. Up to now, these two scales have not been bridged.
Interdisciplinary research
The authors demonstrate a new wavelike adhesion mechanism between atomic deformations and have been achieved by combining analytical and numerical models from engineering and quantum physics. The results of this paper rationalise recent puzzling experimental results on delamination of graphene from different surfaces and several other experiments on adhesion of biological matter to hard material surfaces.
“With a background in computational mechanics, I have always had an interest in physics, but these two disciplines often develop independently. In this paper, we paved the way in the broad and unexplored domain of quantum-continuum simulations. We show that incorporating quantum effects is primordial to extract macroscopic constitutive laws in agreement with experimental data for engineering applications. This work could motivate and guide many future studies at the interface between physics and engineering as it is clear that information on the atomic scale is needed to investigate accurately the mechanics occurring in materials at the macroscopic level”, says Dr. Paul Hauseux, post-doctoral researcher within the Department of Engineering at the University of Luxembourg and first author of the paper.
“Our results provide a first step to understand adhesive interactions between materials from first principles. This is critical in creating lighter, stronger and more resistant materials such as aerospace composites and sensors. To make a headway in this direction, we will have to be able to handle defects, heterogeneities and geometrical complexities, which will be some of our next steps”, explains Prof. Stéphane Bordas, professor of Computational Engineering within the Department of Engineering at the University of Luxembourg.
“The emerging collaboration between my group and the group of Prof. Stéphane Bordas has led to a rather unexpected finding that quantum effects are important at the engineering scale, demonstrating that leading science often happens at the boundaries between different disciplines” – says Prof. Alexandre Tkatchenko, head of Theoretical Chemical Physics group within the Department of Physics and Materials Science at the University of Luxembourg.
“The origin and understanding of phenomena across several length scales within one material is a central subject of materials science. It has fascinated physicists, chemist and engineers for decades. It is a pleasure to see that an interdisciplinary approach of physicists and engineers of the University of Luxembourg has allowed to elucidate several fundamental mechanisms at play, which are also of considerable relevance for a broad spectrum of applications”, comments Prof. Jens Kreisel, Vice-Rector for Research at the University of Luxembourg
Publication: “From quantum to continuum mechanics in the delamination of atomically-thin layers from substrates“, Nature Communications, April 2020