Waves and instability in a one-dimensional microfluidic array

TL;DR

This paper investigates wave phenomena and instabilities in a one-dimensional microfluidic array of water droplets, combining simulations and experiments to analyze hydrodynamic interactions and their nonlinear instabilities.

Contribution

It provides a detailed simulation and experimental validation of wave spectra and instability mechanisms in 1D microfluidic droplet arrays, highlighting nonlinear interaction effects.

Findings

Wave spectra match experimental data

Instability arises from nonlinear hydrodynamic interactions

Localized growth of wave instabilities

Abstract

Motion in a one-dimensional (1D) microfluidic array is simulated. Water droplets, dragged by flowing oil, are arranged in a single row, and due to their hydrodynamic interactions spacing between these droplets oscillates with a wave-like motion that is longitudinal or transverse. The simulation yields wave spectra that agree well with experiment. The wave-like motion has an instability which is confirmed to arise from nonlinearities in the interaction potential. The instability's growth is spatially localized. By selecting an appropriate correlation function, the interaction between the longitudinal and transverse waves is described.