Filtration membrane with ultra-high porosity and pore size controllability fabricated by parylene c molding technique for targeted cell separation from bronchoalveolar lavage fluid (BALF)

This paper presented an effective fabrication strategy to prepare micropore arrayed membrane with ultra-high porosity and pore size controllability based on a Parylene C molding technique. The prepared filtration membrane had small supporting structure between adjacent micropores with width of 4 μm and thereby an ultra-high porosity up to 90.9%. The membrane was 10 μm thick and had a considerable mechanical strength. The aspect ratio even went to 7.5 in small micropore devices (pore size of 1.39 ± 0.067 μm). Bronchoalveolar lavage fluid (BALF) with sparked rare cancer cells was sequentially filtrated through membranes with different pore sizes in an integrated device. The preliminary results indicated that the present multiplex filtration device can get a high targeted cell separation yield of 96.5% and purity of 100% with throughput as high as 2 mL/min.