ReportsPhysics

How boundaries shape chemical delivery in microfluidics

See allHide authors and affiliations

Science  17 Nov 2016:
aag0532
DOI: 10.1126/science.aag0532

You are currently viewing the abstract.

View Full Text

Log in to view the full text

Log in through your institution

Log in through your institution

Abstract

Many microfluidic systems including chemical reaction, sample analysis, separation, chemotaxis, and drug development and injection, require control and precision of solute transport. While concentration levels are easily specified at injection, pressure-driven transport through channels is known to spread the initial distribution resulting in reduced concentrations downstream. Here, we document an unexpected phenomenon: the channel’s cross-sectional aspect ratio alone can control the shape of the concentration profile along the channel length. Thin channels (aspect ratio << 1) deliver solutes arriving with sharp fronts and tapering tails, whereas thick (aspect ratio ~ 1) channels produce the opposite effect. This occurs for rectangular and elliptical pipes independent of initial distributions. This makes it possible to deliver solute with prescribed distributions, ranging from gradual buildup to sudden delivery, based only on the channel dimensions.

View Full Text