Gradient structures interfacing microfluidics and nanofluidics, methods for fabrication and uses thereof

A method for fabricating a fluidic device comprising the steps of:

• providing a nanofluidic area on a substrate, the nanofluidic area capable of communicating fluid therethrough, the nanofluidic area comprising a plurality of nanofluidic structures capable of being substantially enclosed between the substrate and a sealing material surmounting said nanofluidic structures, the plurality of nanofluidic structures characterized as having a lateral spacing distance in the range of from about 2 nm to about 200 nm;
• forming a microfluidic area on said substrate, the microfluidic area capable of communicating fluid therethrough, the microfluidic area comprising a plurality of microfluidic structures capable of being substantially enclosed between the substrate and the sealing material, the plurality of microfluidic structures characterized as having a lateral spacing distance in the range of from about 0.5 microns to about 5 microns;
• and
• forming a gradient interface area between said nanofluidic area and said microfluidic area, said gradient interface area capable of being in fluid communication between said nanofluidic area and said microfluidic area, said gradient interface area comprising a plurality of gradient structures capable of being substantially enclosed between the substrate and the sealing material, the plurality of gradient structures characterized as having a lateral spacing distance relative to each other, and the gradient interface area characterized as having a vertical spacing distance relative to the substrate and the sealing material, wherein the lateral spacing distance between the gradient structures, or the vertical spacing distance of the gradient interface area, or both, ranges from about 0.5 microns to about 5 microns adjacent to said microfluidic area to about 2 nm to about 200 nm adjacent to said nanofluidic area;
• wherein said steps of forming said gradient interface area and forming said microfluidic area are formed simultaneously by the steps of:
• coating photoresist over said substrate;
• providing a photomask over said photoresist, said photomask patterning said microfluidic area and said gradient interface area;
• providing a blocking mask over said photomask, said blocking mask extending over a portion of said photomask applied over said nanofluidic area;
• and
• exposing said photomask to light.