Flow-Based Particle Trapping and Manipulation

Flow-Based Particle Trapping and Manipulation, Fig. 3 (a) Hydrodynamic trap based on microeddies generated by low-frequency fluid oscillations around a cylinder in a microchannel. (b) Image showing four trapped microspheres using microeddies around a cylindrical post. Arrow indicates the direction of fluid oscillations. (Scale bar, 250 pm) (a, b) (Reprinted with permission from [7] 2006 American Chemical Society). (c) Hydrodynamic trap based on microvortices... 

Flow-Based Particle Trapping and Manipulation, Fig. 7 Time-lapse image of the relaxation dynamics of an individual single-stranded DNA molecule (ssDNA, L = 18 jm) studied by the hydrodynamic trap based on a planar extensional flow. A single fluorescently labeled... 

Although contact-based methods have proved useful for biological studies, there is a strong need for contact-free, flow-based methods for precise confinement and manipulation of biomolecules and cells. To this end, a number of contact-free fluid flow-based trapping and manipulation methods have been developed. These methods rely on microvortices, microeddies, stagnation point flows, or stagnant regions within a fluid stream to confine particles for further analysis. 

Flow-based confinement and manipulation methods offer a new platform for observation of molecules, cells, and particles without surface immobilization, eliminates potentially perturbative optical, magnetic, and electric fields. Examples provided below highlight different applications for each category of flow-based trapping ... 

---