Programmable metainterfaces for friction control
This project was funded by ANR through Grant
optimization of the devices involving functional contacts would enable
significant energy savings, at the beginning of the project, there was no
established method to prepare an interface with pre-defined frictional
properties. The aim of PROMETAF has been to propose a simple and generic
surface design strategy to obtain such interfaces.
The idea has been to build surfaces with a
deterministic texture, by placing model asperities, one by one, on a deformable
substrate. By tuning the shape and altitude of each individual asperity, we
have been piloting the macroscopic behaviour of the
interface, while targeting unprecedented frictional properties. In practice we
have explored various types of interfaces giving access to various pre-defined,
non-linear friction laws, some of which connecting working conditions usually
This newly accessible toolbox is expected to be useful
to advance the state-of-the-art, both by questioning the usual approach to
friction control through homogeneous surface coatings, and by extending the
range of applications of metamaterials to friction.
To validate a new interface design, the following
three main methods are used.
First, we identify the relevant multi-asperity model,
based on a preliminary calibration of the tribological
behavior of a single microcontact. The model is then
inverted, to predict the list of geometrical descriptors of all individual
asperities (radii of curvature, altitudes) that is expected to provide the
desired macroscale frictional behavior. In this project, we used analytical
Second, we fabricate an elastomer substrate according
to surface topography prescribed by the inversion. We prepare an aluminum mold
decorated by an array of spherical holes with the prescribed individual depths,
and use it to obtain a polydimethylsiloxane (PDMS) substrate with the negative
topography: an array of spherical asperities.
Third, we form a contact between the textured PDMS and
a smooth glass substrate, and perform mechanical tests in order to measure the
friction law of the interface (friction force vs normal force). The
experimental friction law is finally compared quantitatively to the desired
Using the above methods, we validated various original
interface designs. Those include: (i) interfaces
whose friction laws passes through three operating points usually considered as
incompatible, (ii) interfaces whose friction coefficient can be tuned on-demand
and (iii) interfaces featuring two different friction coefficients according to
the range of normal force applied to the contact.
Illustration of the design strategy
Flowchart of the design strategy. Upper
sketch: single microcontact submitted to a normal
force p and a friction force f. Lower sketch: metainterface
submitted to normal and friction forces, P and F. Black ellipses: real contact
Outputs of the project
peer-reviewed international journals
Oral communications in international conferences
J. Scheibert. Approche modèle en tribologie :
application aux contacts élastomères secs. Journées
Internationales Francophones de Tribologie 2021. Distanciel.
A. Aymard. Friction law
of model asperity-based rough elastomer contacts. Contact Mechanics International Symposium 2022, Chexbres,
 J. Scheibert.
morphology changes in rough elastomer interfaces. Contact Mechanics International
Symposium 2022, Chexbres, Switzerland. Invited conference
 A. Aymard.
Design and realization of metasurfaces with tunable
friction law. 7th World
Tribology Congress, Lyon, France
 J. Scheibert.
Creating soft interfaces with pre-defined static friction forces. 9th International Tribology Congress, 2023,
Fukuoka, Japan. Invited conference
Oral communications in national conferences
 A. Aymard. Realisation of surfaces with controlled friction
laws. 17èmes Journées de la Matière
Condensée 2021, Rennes, France
E. Delplanque. Résolution des erreurs de forme dépendantes du protocole de
durcissement, lors de la réplication par du PDMS. Journée 50 ans du groupe français des polymères, 2021, Lyon, France
J. Scheibert. Frictional metainterfaces. Journée
« Soft metamaterials » du GDR MEPHY,
2023, Paris, France