Three-dimensional microfluidic devices

The device of 1 wherein a said reagent comprises a protein assay reagent, a glucose assay reagent, a sodium acetoacetate assay reagent, a sodium nitrite assay reagent, or a combination thereof.

A three-dimensional device for assay of a fluid sample, the device comprising at least first and second stacked, porous, hydrophilic layers each of which comprise a pattern of fluid-impermeable barriers that substantially permeate the thickness of the layer to define boundaries within each said layer of one or more hydrophilic regions of said hydrophilic layers that wick fluids laterally by capillary action through the porous hydrophilic regions of said hydrophilic layers;

• a fluid-impermeable layer disposed between said first and second layers defining one or more openings communicating vertically between hydrophilic regions in separate layers;
• and
• disposed in a said opening in fluid communication with a said layer, a chemical or biological reagent, an indicator, a binder, a fluid flow-impeding agent, a fluid flow-promoting agent, magnetic particles, a gel which swells when in contact with fluid, a fluid-mixable material which dissolves when in contact with fluid to allow microfluidic communication, a salt which either absorbs heat or gives off heat when in contact with fluid, a low-melting-point hydrophobic material capable of melting and flowing at a pre-selected temperature to flow into and thereby obstruct microfluidic flow within a said hydrophilic region, or a combination thereof.