TOWARDS FIBER-BASED MICRO- AND NANOFLUIDICS

摘要

We describe a new method of controlled manipulation of micro-quantities of fluids by using a conduit formed by two parallel fibers. We show that a droplet of a wetting fluid, which is deposited on the fiber rails, can be either pinned at the point of deposition or driven to spread along the inter-fiber channel. The principle of controlled manipulation is that the droplet spreads out or comes back spontaneously due to the action of capillary forces, which critically depend upon the interfiber spacing. Compared to conventional microchannel design, the suggested fiber-based conduits significantly reduce the viscous drag. We present a quantitative analysis of the phenomenon of droplet spreading and the critical conditions for droplet pinning. Depending on the fiber diameter, the fiber-based conduits provide an opportunity of fluid manipulation in micro- and nanofluidic devices.