skip to: onlinetools | mainnavigation | content | footer

Research in Microfluidics 

MicroChemLab™ biodetector


Research in Microfluidic Transport at Sandia National Laboratories

Programmable Membranes for Microchip Dialysis

Sandia National Laboratories, Livermore, CA

Complex samples (e.g., cell extract) often require extensive cleanup or pretreatment before introduction to analysis channels in a miniaturized device. These pretreatment steps are often performed off-chip using large volumes of sample and other reagents, and hence often add substantially to the total analysis time and cost.

Dialysis, or size-based separation of species via selective diffusion through a semipermeable membrane, is a widely used technique for cleanup of biological samples. We have developed a technique for fabricating thin (4-14 micron) porous polymer dialysis membranes within the channels of a glass microchip. UV laser-initiated polymerization is used for controlled placement of the dialysis membrane in a chip for cleanup of complex or dirty samples; this technique is rapid and inexpensive and increases the potential functionality of integrated microfluidic devices. The semipermeable membrane and fabrication technique shows the potential for extracting a small molecular weight analyte of interest from a complex matrix.



S. Song, A.K. Singh, B.J. Kirby
"Electrophoretic Concentration of Proteins at Laser-Patterned Porous Membranes," submitted.


S. Song, A.K. Singh, T.J. Shepodd, B.J. Kirby "In-situ fabrication of Nanoporous Polymer Membranes for Microdialysis of Proteins," Analytical Chemistry, accepted.


B.J. Kirby, A.K. Singh
" In-situ fabrication of dialysis membranes in glass microchannels using laser-induced phase-separation polymerization," MicroTAS 2002, p.742-744, 2002.

For Further Information Contact: Malin Young