Microbial cells trapping and detection through filterbased microfluidic devices

Trapping efficiency up to 90% with 12 microbial cells was achieved by optimizing sample delivery and filter design in a microfluidic device, and using a novel injection approach. Cell loss during sample delivery was significantly minimized by increasing the tubing diameter used for the connection between sample storage and micro-device. A hydrodynamic focusing approach was used to reduce cells contacting and adhesion on the walls of micro-channel and chip inlet. We also optimized the pillar design with a zigzag arrangement (13 μm in chamber depth and 0.8 μm in gap) to prolong the effective length of cell trapping, and to reduce the gap length between any two given pillar (i.e. pressure drop) at the filter region.