Microparticle Manipulation Performed on a Swirl-Based Microfluidic Chip Featured by Dual-Stagnation Points

作者:Dang, Yanping; Hu, Shuai; Ou, Zhiming; Zhang, Qin*
来源:Langmuir : the ACS journal of surfaces and colloids , 2023, 39(32): 11245-11258.
DOI:10.1021/acs.langmuir.3c00794

摘要

Stagnation-based microfluidics technologyis promising for microparticlecontrol due to its noncontact and low cost. However, the current researchis still hindered by insufficient pose regulating ability and softcontrol. Based on our previous work on controlling single particlesby generating a swirling flow region (SFR) with a stagnation pointin the designed flow field, a new 3-microchannel structure is hereinproposed for simultaneous control of two microparticles. It is addressedas the dual-stagnation model because there are two SFRs generatedfor particle capturing and manipulation. Simulation study is conductedto optimize the fluid field structure and explore the regulation ofthe two SFRs by adjusting velocities of microchannel inlets. Experimentsare carried out on a 3D-printed microfluidic chip to validate thefeasibility of the dual-stagnation model and the predicting capacityof the simulations. It is demonstrated that two SFRs with stagnationpoints are successfully formed in specific locations, indicating thattwo microparticles can be concurrently captured and controlled. Significantly,the results of simulation and experimental studies agree well witheach other referring to flow streamlines and stagnation point regulation.During experiments, it is confirmed that microparticles with differentshapes and varied sizes can be captured. Besides, the deviation betweenthe positions of microparticles and the generated stagnation pointsis characterized to reveal the trapping stability of this microfluidicchip. This work contributes to an advanced flow field structure forswirl-based microfluidic chips and provides insights into soft contactand flexible manipulation of multiple microparticles for revealingthe interaction between two bio-/chemical microparticles.

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