PROJECT TITLE :

Simulation-based method for optimum microfluidic sample dilution using weighted mix-split of droplets

ABSTRACT:

Digital microfluidics has recently emerged as an efficient technology in providing cheap however reliable solutions to various biomedical and healthcare applications. On-chip dilution of a fluid sample to realize a desired concentration is a vital drawback in the context of droplet-based mostly microfluidic systems. Existing dilution algorithms deploy a sequence of balanced combine-split steps, where two unit-volume droplets of different concentrations are mixed, followed by a balanced-split operation to obtain two equal-sized droplets. During this study, the authors study the problem of generating dilutions employing a combination of (1 : 1) and (one:two) mix/split operations, called weighted dilution (WD), and present a layout design to implement such WD-steps. The authors additionally describe a simulation based technique to seek out the optimal mix-split steps for generating a dilution below various criteria such as minimisation of waste, sample, or buffer droplets. The sequences can be stored in a very look-up table a priori, and used later in real time for quick generation of actuation sequences. Compared with the balanced (1:one) model, the proposed WD theme reduces the number of combine-split steps by around twenty twop.c, and the quantity of waste droplets, by 18%.