Methods for fabricating electrokinetic concentration devices

A method of concentrating a species of interest in a liquid, the method comprising applying said liquid comprising said species of interest to a concentrating device comprising:

• a fluidic chip comprising a planar array of channels through which a liquid comprising a species of interest can be made to pass;
• at least one rigid substrate connected thereto such that at least a portion of a surface of said substrate bounds said channels;
• and
• a high aspect ratio ion-selective membrane embedded within said chip, attached to at least a portion of said channels.

A method for the preparation of a concentrating device comprising:

• a fluidic chip comprising a planar array of channels through which a liquid comprising a species of interest can be made to pass;
• at least one rigid substrate connected thereto such that at least a portion of a surface of said substrate bounds said channels;
• and
• a high aspect ratio ion-selective membrane embedded within said chip, attached to at least a portion of said channels;
• said method comprising:
• forming a high aspect ratio trench in said fluidic chip, such that the trench is perpendicular to the long axis of said channels, and such that the trench depth equals or exceeds the depth of said channels in said fluidic chip;
• bending said fluidic chip parallel to the long axis of said trench, such that at least a portion of said trench becomes wider;
• applying a liquid polymer to an area proximal to one end of said trench such that the liquid polymer is allowed to flow along the trench and fill the trench.
• unbending said fluidic chip such that said liquid polymer is strongly adhered to said trench;
• providing conditions such that said liquid polymer forms a high aspect ratio ion selective membrane embedded in said trench;
• and
• optionally removing residues of said polymer from areas of said fluidic chip proximal to the trench;
• attaching said one rigid substrate to said fluidic chip comprising channels such that said channels bound at least a portion of a surface of said substrate.