Silicon membrane filter designed by fluid dynamics simulation and near-field stress analysis for selective cell enrichment.

Selective cell enrichment technologies can play an important role in both diagnostic and therapeutic areas. However, currently used cell sorting techniques have difficulties in rapidly isolating only the desired target cells from a large volume of body fluids. In this work, we developed a filtering system that can quickly separate and highly concentrate cells from a large volume of solution, depending on their size, using a silicon membrane filter. To overcome the problems caused by material limitations of the brittle silicon, we designed a novel membrane filter with various pore designs. From these designs, the most optimal design with high pore density, while preventing crack formation was derived by applying fluid dynamics simulation and near-field stress analysis. The membrane filter system using the selected design was fabricated, and cell filtration performance was evaluated. The LNCaP cell in horse blood was recovered up to 86% and enriched to 187-fold compared to initial cell populations after filtration at a flow rate of 5 mL/min. The results demonstrate that the filter presented in this study can rapidly and selectively isolate target cells from a large volume of body fluid sample.