Microfluidic network-based combinatorial dilution device with an initial concentration controller

In this paper, we present a flow-specific initial concentration controller connected to a combinatorial dilution device, which could generate arbitrary, predictable, and systematic combinatorial dilutions of all the solutions in response to variable input flows. We investigate the performance of the initial controller by computational simulation (CFD-ACE⁺). The simulated output concentrations had very low tolerance compared to theoretical value with error < 1%. Linearity was tested with fluorescent dye (sodium salt) for 3 samples and DI water for buffer by employing a separate initial concentration module. Then, a combinatorial dilution device integrated with the initial concentration module was tested. The device showed CV error less than 10%. As proof-of-concept, we performed a simple combinatorial cytotoxicity screening with 3 drugs (Mitomycin-C, Doxorubicin, and 5-FU) for MCF-7 cancer cell.