Abstract

Utilizing Microfluidic Components to Enhance Performance in Analytical Instrumentation

Elisabeth Verpoorte, Professor, Pharmaceutical Analysis, University of Groningen

The hallmark of microfluidics is the unique ability to controllably manipulate minute liquid volumes to achieve enhanced (bio)chemical processing and (bio)analysis. A host of chemistry and life science disciplines are benefiting from the development of lab-on-a-chip devices offering this capability to address a wide range of applications. Devices may be implemented either as stand-alone tools or, increasingly, as components to impart additional function to existing instrumentation. The success of microfluidics thus continues to rely on the incorporation of simple, robust approaches for flow-control functions like valving and mixing. This presentation will focus on two examples from our labs in which microfluidics is contributing to the development of miniaturized analytical instrumentation. In the first, the design of a chaotic micromixer, originally proposed by Stroock et al. (Science 2002), incorporating arrays of herringbone grooves is described for application in two-dimensional chromatography. The demands imposed on the fabrication of this mixer have been stringent, as the mixer has to be able to withstand pressures greater than 100 bar. In addition, the material used must be compatible with the solvents employed in liquid chromatography. In the second example, paper is the material of choice for the microfluidic components presented. Flow control in paper devices can be achieved using an on-off valving approach based on selective permeability, in which the resistance of patterned hydrophobic barriers in paper to being breached by a fluid depends on fluid composition. Application of this valving mechanism to the configuration of volume-defined sampling, multi-step reactions and sample concentration on paper will be demonstrated.