title: Permeation-driven flow in poly(dimethylsiloxane) microfluidic devices.
abstract: Poly(dimethylsiloxane) is currently the material of choice for rapidly fabricating microfluidic devices. As the size of these devices decreases, a significant hydrodynamic flow is generated due to permeation of fluid through the channel walls. We develop a theoretical model verified by single bead tracking experiments, which demonstrates that large flow rates (>10 microm/s) can be passively generated in a straight microchannel filled with water. Realizing that this flow may be unwanted in some applications, we present a method to eliminate it by inhibiting mass transfer of water into the poly(dimethylsiloxane) walls. Furthermore, we explore applications to harness this passively generated flow inside a microfluidic device such as bead stacking, chemical concentration, and passive pumping.
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
authors.forename: Greg C
authors.initials: GC
authors.lastname: Randall
authors.forename: Patrick S
authors.initials: PS
authors.lastname: Doyle