Design and fabrication of a PDMS microfluidic device for titration of biological solutions

Abstract

This paper presents microfluidic device, constructed from polydimethylsiloxane and glass, which is designed to perform on-chip micro-titration of biological solutions. The chip is composed of several mixing microchannels that measures 100 × 100μm2 in extent and that automatically dilute an oxidizing agent in order to determine the amount of reducing agent present in biological solution. Concept of the diffusion as a dominant process for fluid mixing and achieving gradient of dilution, is analysed and reviewed. Types of biological samples, length of the mixing channel, input flow rate and applied pressure are discussed as main design parameters. Experimental results of utilizing the chip in microtitration studies are presented.