MEMS LC microchip with low dispersion and low pressure drop turn structure using distribution controlled micro pillar array

MEMS liquid chromatography (LC) microchip with low dispersion and a low pressure drop turn structure was fabricated. In the turn structure, we used higher density pillar array at the inner side while lower density pillar array was used at the outer side to control inner and outer speed of a sample flow. An LC chip with an improved turn structure can obtain similar theoretical plate number (1233) compared to the previously proposed tapered turn (1135). The necessary inlet pressure is also reduced from 2.7 to 0.4 MPa under a flow rate of 10 μL/min. These results show the improved turn structure is applicable for fast analysis time under high flow rate conditions.