Instabilities in droplets spreading on gels

Abstract

We report a novel surface-tension driven instability observed for droplets spreading on a compliant substrate. When a droplet is released on the surface of an agar gel, it forms arms/cracks when the ratio of surface tension gradient to gel strength is sufficiently large. We explore a range of gel strengths and droplet surface tensions and find that the onset of the instability and the number of arms depend on the ratio of surface tension to gel strength. However, the arm length grows with an apparently universal law L ~ t^{3/4}.

References in corpus (2)

• Surfactant Driven Fracture of Interfacial Particle Rafts
• Bi-Laplacian Growth Patterns in Disordered Media

Cited by in corpus (7)

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• Reversal of Solvent Migration in Poroelastic Folds
• Role of normal stress in the creep dynamics and failure of a biopolymer gel