Analysis of chaos and FRET reaction in split-and-recombine microreactors

The mixing and reaction performance of a split-and-recombine (SAR) microreactor was enhanced on modification of the geometric configuration. A rotation of fluid is induced on shrinking the structure of the splitting and reorientation region in alternate directions, thus improving the pattern of multi-lamination and enhancing the chaos of the fluid. To design and to analyze systematically the performance of the reactors, an effective method involving chaotic analysis and fluorescent resonant-energy transfer (FRET) is proposed. The structural design of a passive microreactor to generate an effective contact between the reagents is of great practical significance. SAR microreactors of four types with various microstructures were designed to illustrate the effects of geometric patterns (i.e., arrangement and dimensions) on mixing and reaction. Through analysis of the chaos, we revealed numerically the dynamic mixing governed by multi-lamination and chaotic mechanisms in the devices. The results show that specific structural designs induce rotation and rearrangement of fluids, thus elongating their material interface; the mixing of the fluids consequently improved. We investigated the hybridization of two complementarily labeled oligonucleotides in the devices by means of FRET. How the devices affected the rate of hybridization was thereby assessed, verifying that FRET is a technique capable of estimating the practical applicability of these devices.