An elaborated mechanism for sheath flow forming includes flow cell, vacuum pool, sample pool, syringes, valves, and
tubes. Firstly the sample is drawn into the sample inlet of flow cell through vacuum generated with one syringe. Then,
the sample and buffer are driven to pass the flow cell to form sheath flow by other two syringes. To visualize and
evaluate the sheath flow, black ink is used as sample, and optical imaging system is adopted to capture the formed sheath
flow. Sheath flows with sample width of 21μm and 37μm in diameter are formed in a flow cell with micro-square hole of
the size 0.2mm×0.2mm when the syringes run in different speed.