Accelerated Chemical Reactions for Lab-on-a-Chip Applications Using Electrowetting-Induced Droplet Self-Oscillations

Abstract

AbstractThis paper summarizes the results of experimental investigations of the feasibility of applying electrowetting-induced droplet self-oscillations to induce rapid mixing of small quantities of liquids. The concept was tested using video microscopy to monitor the mixing of passive colored dyes, of spatially-separated reactants that change color upon reaction, and of fluorescent DNA oligomers whose light emission vanishes upon hybridization with appropriately-functionalized complementary DNA strands. Droplet self-oscillation was found to increase the rate of mixing by factors ranging from 15 to 100 as compared with the rate of passive diffusion in undisturbed droplets. This demonstrates that self-oscillation-induced mixing is a viable method for substantially enhancing the speed of chemical reactions in general, and biochemical assays in particular, when performed in small volumes of liquids.