Universality of friction laws on liquid-infused materials

Liquid-infused surfaces (LISs) make drops remarkably mobile. However, the dynamics of those drops proved to be subtle, due to the numerous phases at stake (lubricating liquid, drop, solid texture, and air). In this article, we highlight the role played by a feature specific to LISs, namely, the "foot" of oil surrounding the drops and drawn by their surface tension. Consequently, viscous dissipation can be localized in four distinct regions, which we tune independently through various experimental setups. Despite this complexity, we evidence a universal scaling for the friction law and reconcile recent results produced on this topic.