A swirl-based microfluidic chip for microparticle capture and assembly

Abstract Due to its reliable security and advanced integration, microfluidic technology has attracted considerable scholar attention as it can be applied in extensive technical fields, such as particle manipulation, pharmaceutical analysis, etc. Our team has previously conducted research on swirl-based microfluidic chips for microparticle manipulation, including trapping and enriching. Herein, a swirl-based 4-microchannel microfluidic chip is proposed for microparticle capture, transfer and assembly. The generation of the swirling flow region is firstly verified by finite volume simulation, and the microfluidic chip is fabricated by 3D printing technology to further validate its function. Experiments and force analysis of microparticle motions are performed to demonstrate the capturing, trapping, and transferring ability of the microfluidic chip. It is worth mentioning that the microparticles assembly can be facilitated and optimized simply by regulating the microchannel flow rate of the microfluidic chip. The capturing and trapping capacity of the microchannel are also investigated through simulations with different microchannel flow rates, evaluated by specific flow field parameters. Besides, an image processing algorithm is developed to enhance the microparticle assembly. The proposed microfluidic chip provides a safe and feasible method for capture and directed assembly of microparticles, which can be further designed as bio-sensors to analyze the physical and chemical properties of microparticles.