Passive distributing method for cellular diagnostic microwell array using self-regulating pinched flow

We developed passive cell distributing method for cellular diagnostic microwell array. This method can distribute cells evenly and simultaneously to a number of microwells only by introducing cell suspensions from the inlet. In order to reduce the dispersion of the number of distributed cells to each microwell, we propose a novel concept of the self-regulating pinched flow. The self-regulating pinched flow is realized in a microchannel, which consists of the center micropillar colonnades and side channels. CFD simulations were carried out to optimize the design of the pinching area. Using a fabricated prototype device having 8 microwells, uniform distribution of the beads was obtained successfully. The coefficient of variation (CV) of the distributed bead in microwells was 29.3%.