Modeling of Contactless Bubble-Bubble Interactions in Microchannels with Integrated Inertial Pumps


Inertial pumps hold great promise to democratize microfluidics by integrating scalable, mass producible micro-pumps with no moving parts directly in microfluidic channels. This technology has been used for pumping, mixing, routing, sorting, and cell lysis. In this study, we explore the interaction of two vapor bubbles in a microchannel through CFD and 1D modeling. We envision the developed 1D model as a first-order rapid design tool for inertial pump-based microfluidic systems operating in the contactless bubble-bubble interaction nonlinear regime.

Main Learnings

  • Pre-collapse and post-collapse bubble and flow dynamics for two resistors in a microchannel can be successfully modeled by a reduced parameter one-dimensional model

  • Net pumping effect for two resistor firing is a function of resistor placement and firing time delay

  • One-dimensional model loses accuracy at near-reservoir resistor placements due to reservoir interactions

  • One-dimensional model loses accuracy when the firing time delay is less than the time required for the vapor bubble to fill the channel cross-section