Microfluidic channel fabrication method

A method for fabricating a microfluidic device, comprising:

• a) providing a substrate having upper and a lower opposing faces and an electrically conducting material disposed on the upper face to form a conductor/substrate assembly;
• b) patterning a mask on the surface of the electrical conductor form a desired arrangement of channels on the electrical conductor and to define the thickness of the channel walls;
• c) etching away that part of the electrical conductor not protected by the mask to form channel walls joined to and extending from the upper face of the substrate;
• d) removing the mask;
• and
• e) sealing a cover plate to the tops of the channel walls to define sealed channel structures between the substrate and the cover plate, wherein the cover plate is configured to provide access to the channel structure.

A method of forming a capillary structure, comprising:

• a) providing a substrate having upper and a lower opposing faces and having an electrically conducting material disposed on the upper face to form a first conductor/substrate assembly;
• b) providing a second conductor/substrate assembly;
• c) patterning a mask on the surface of at least one of the conductor/substrate assemblies, wherein the mask pattern and the thickness of the conductors together define the thickness of the capillary walls;
• d) etching away that part of the conductor not protected by the mask to form a channel structure joined to and extending from the substrate;
• e) aligning the structures on the first and second conductor/substrate assemblies to define an elongate bore;
• and
• f) joining the aligned structures.