Exploring Hydrodynamic Flow-regulated Deformable Microfluidics for Nanoparticles Trapping and Release

Studying the regulation of hydrodynamic flow within a micro-/nanofluidic channel, in recent years, has been an attractive field and it could be beneficial for biomedical applications, such as cell or particle manipulation, nanotechnology, and optical sensing. The deformable microfluidic devices could be an excellent candidate for targeting a well-tunable micro-/nanoparticles trapping and release. Initially, we proposed a one-dimensional nano-sieve device ¹, consisting of deformable polydimethylsiloxane (PDMS) layer and a narrow channel (~200 nm in thickness) on a glass substrate, to achieve the microparticles trapping and release by simply tunning the applied flow rate. A theoretical model was built to explore the fluid-structure interaction between the hydrodynamic flow and target particles, which reveals the mechanisms behind the experimental data, further predicting the capture efficiency within such a nano-sieve device. Leveraging the capacity of this nano-sieve system, we introduced a three-dimensional (3-D) beads-stacked microstructure to enhance the efficiency of capture and enable the concentration of target particles from bio-samples ². The profile of stacked beads induced by hydrodynamic flow within the nano-sieve channel was investigated using computational fluid dynamics (CFD) model ² and the theoretical model ³. This study could play a crucial role in optimizing next-generation deformable microfluidic devices, enhancing their efficiency in manipulating micro-/nanostructure.