Narrowing Microfluidics Width in Microchannel using Air Boundaries

A novel method for narrowing microfluid width in microchannel is presented by utilizing of air boundaries of which inflation direction is perpendicular to microfluid flow. The air boundaries are generated by heating water with microheater. The microfluid width of 300 pm can be focused and maintained as up to 22 pm which is near cell size without affecting cell or microchannel structure. The narrowed width is regulated by pressure in the air boundaries and flow velocity of microfluid. The method can enhance sensitivity in flow cytometry by placing the air boundaries near sensing area and guiding cells.