Diversity-induced resonance at surfactant-laden interfaces.

Abstract

Networks of coupled nonlinear elements can amplify weak periodic signals when unit heterogeneity is intermediate-a phenomenon known as diversity-induced resonance (DIR). We test this mechanism at surfactant-laden interfaces by modeling the interface as a two-dimensional lattice of laterally coupled patches obeying Frumkin adsorption-desorption kinetics, driven by sinusoidal modulation of the monomer concentration; diversity enters as patchwise variability in the adsorption drive. Using linear analysis and numerical simulations, we compute the first-harmonic gain of the mean surface coverage while sweeping diversity and other parameters, and connect the model to experimental observables. Intermediate diversity maximizes the collective response, increasing mean coverage by ∼3-4× versus a homogeneous interface and improving robustness to frequency variations, consistent with DIR. Because the effect emerges from network coupling, the model requires no empirical time constants or ad hoc relaxation pathways.