Fluid Dynamics

Surfactant and Elastic Effects in Microfluidic Devices (Nivedita Gupta)
Kingsbury S341

Niva lab

Tremendous progress has been made in the development of microfluidic devices in the last decade with applications such as a "lab-on-a-chip", ink-jet printer heads, cell sorters, DNA sequencers, and blood-testing systems. Microdroplets are being used in microfluidic devices as actuators, chemical microreactors, drug delivery devices, and bioterror detection tools. Typical applications of two-phase systems in microdevices involve viscoelastic fluids such as DNA solutions, blood, serum, and inks and suspensions with surfactants added as stabilizers. The stretching of polymer chains present in viscoelastic fluids causes large normal stresses to develop at deforming interfaces affecting the dynamics of drops. Surfactant molecules adsorbed at the interface can redistribute along the interface leading to a local reduction in surface tension. The major research objectives of this study are to identify parameters governing the shape and velocity of drops translating in rectangular microchannels and the effect of elastic stresses and surfactant mass transfer kinetics on the dynamics of drops in the microchannel.

Drops

 

Surfactant