Realization of 240 nanometer resolution of cell positioning by a virtual flow reduction mechanism

This paper presents the real-time precise positioning of a single cell with extremely high resolution. The positioning system is based on the visual feedback control of the syringe pump. The issue for using a syringe is that the flow rate is geometrically amplified in microchannel due to the ratio of cross sectional areas of the syringe and the microchannel. In order to overcome this issue, we introduce the virtual flow reduction mechanism. This mechanism utilizes the elasticity of poly-dimethylpolysiloxane (PDMS) microfluidic chip where the pressure peak is limited but the pressure response decreases with a sufficiently large time constant compared with the sampling time. By using this characteristic, we design and develop the system together with an online vision system. Through experiments, we could confirm that the cell positioning resolution is 240 nm corresponding to 1 pixel of the vision.