Absorbent-force-driven microflow cytometer

This work developed an absorbent-force-driven microflow cytometer chip (AMCC), in which solutions were driven by the absorbent force of superabsorbent materials to allow chip operation without external power and easy miniaturization. The polydimethylsiloxane (PDMS) cover of the microflow cytometer chip containing microchannels and reservoirs was fabricated by soft lithography and then bonded to a glass substrate. Then, superabsorbent material was put into contact with the microchannel's end to drive the test solution from the reservoir to the superabsorbent material through the microchannel, forming a complete AMCC. The flow characteristics inside the AMCC, the impact of the microstructure size on the flow velocity and hydrodynamic focusing width of AMCC, and the optimized laser-induced fluorescence (LIF) detection system parameters were investigated in this work. Results showed that superabsorbent materials allowed stable microchannel flow and hydrodynamic focusing and that the flow rate and hydrodynamic focusing width of the AMCC could be controlled by varying the microchannel dimensions. The AMCC was integrated with the LIF detection system to detect the fluorescence of calibration particles, and the fluorescence results were consistent with those from a large-scale flow cytometer (BD, FACSCalibur), confirming the successful use of superabsorbent material as the fluid-driving source in an AMCC. (C) 2014 Elsevier B.V. All rights reserved.