On-Chip Sample Pretreatment for Biochips: Nanoporous Polymer Membrane and Dielectrophoresis

Abstract

The advent of microfluidic chips (or biochip) enables automation of a labor-intensive biochemical analysis process and reduction of sample consumption. Numerous studies have been performed to incorporate various functions such as sample cleanup, sample preconcentration, mixing, reaction, separation, and detection into the biochips over the past decade. However, most studies were focused on miniaturization of sampling and sample analysis. Now, more research has paid attention to miniaturizing the sample pretreatment process because it is a bottle neck of full automation of the entire process. This presentation will discuss on-chip sample pretreatment techniques developed using nanoporous polymer membranes and numerical studies on dielectrophoresis in microchannels. A unique technique was developed to laser-pattern nanoporous polymer membranes in a biochip using a projection lithography and phase separation polymerization. The membranes are used for microdialysis and preconcentration of proteins and engineered for different membrane sizes, shapes and the pore sizes. In addition, numerical studies have been performed to characterize electrokinetic and dielectrophoretic phenomena in microchannels.