Implementing series of dual-chamber units for sequential loading of the liquids in centrifugal microfluidic platforms

Abstract

Liquids flow control plays a critical role in the designing of microfluidic networks for utilizing in the lab-on-a-chip devices as a modern platform for miniaturizing and automating medical diagnostic tests. In some applications such as immunoassay, it is essential to use different samples and reagent liquids in a series of sequential steps based on the test procedures. Thus far, a number of studies have reported associated methods mostly employing a different kind of the micro-valves. We introduce the concept of a dual-chamber, a passive method for the sequential entrance of any kind of liquids into a chamber in centrifugal microfluidics. The mechanism relies on the ability of the liquid pumping by employing its rotational potential energy through an abrupt angular deceleration of the containing disk. The model is analyzed theoretically, numerically and experimentally for optimizing the geometrical design to reach to the maximum liquid transfer efficiency. Furthermore, a model comprising of several dual-chamber units is presented and experimented based on the optimized designs. The results show that the presented method has a high ability of precise and efficient liquid transfer in the centrifugal microfluidic platforms through a simple and highly integrated approach.