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Accueil > Publications > Archives 2004-2010 > 2007

Control and Measurement of the Phase Behavior of Aqueous Solutions Using Microfluidics

J. Shim, G. Cristobal, D. R. Link, T. Thorsen, Y. Jia, K. Piattelli, and S. Fraden — JACS 129 (2007)

publié le , mis à jour le

A microfluidic device denoted the Phase Chiphas been designed to measure and manipulate
the phase diagram of multicomponent fluid mixtures. The Phase Chip exploits the permeation of water
through poly(dimethylsiloxane) (PDMS) in order to controllably vary the concentration of solutes in aqueous
nanoliter volume microdrops stored in wells. The permeation of water in the Phase Chip is modeled using
the diffusion equation, and good agreement between experiment and theory is obtained. The Phase Chip
operates by first creating drops of the water/solute mixture whose composition varies sequentially. Next,
drops are transported down channels and guided into storage wells using surface tension forces. Finally,
the solute concentration of each stored drop is simultaneously varied and measured. Two applications of
the Phase Chip are presented. First, the phase diagram of a polymer/salt mixture is measured on-chip and
validated off-chip, and second, protein crystallization rates are enhanced through the manipulation of the
kinetics of nucleation and growth.