Microfluidic devices are prepared by providing a substrate material having a solid adhesive thin sheet, printing solid ink on the substrate using a conventional printer, selectively etching the substrate using a wax masking layer to obtain a desired pattern, removing the masking layer from the substrate, aligning and bonding together the pattern of the substrate to a pattern of a second substrate to form a layer of substrates, and curing the layer of substrates to result in a three-dimensional microfluidic device.