Microfluidics with foams

Abstract

Lab-on-a-chip devices can handle very tiny amounts of fluids, as small as a picolitre. Samples of gas are conveniently encapsulated and transported within bubbles. The generation of these calibrated bubbles involves specific microfluidic devices that we describe. When the bubble concentration is high enough in a channel, they come into contact, and they flow as a crystalline foam. The flow of the foams depends strongly on the arrangement of bubbles within the channel, which entails original dynamical behaviours such as super-stability of the flow, or on the contrary spontaneous oscillations.