Centimeter-Scale Surface Interactions Using Hydrodynamic Flow Confinements.

We present a device and method for selective chemical interactions with immersed substrates at the centimeter-scale. Our implementations enable both, sequential and simultaneous delivery of multiple reagents to a substrate, as well as the creation of gradients of reagents on surfaces. The method is based on localizing submicroliter volumes of liquids on an immersed surface with a microfluidic probe (MFP) using a principle termed hydrodynamic flow confinement (HFC).