Fig. 1.

(a) Schematic layout of the integrated disposable microfluidic device; a μSPE (solid-phase extraction) column, a flap valve, a hydrophobic vent, and microchannels are integrated on a disposable cartridge format, and photograph of the fabricated device. (b) Illustration showing operation of a flap valve; a flap valve opens with the pressure over 3.5 psi inside. (c) Fabrication process of the device; a top channel layer, a flap valve layer and a bottom reactor layer were cut and thermally bonded each other and then assembled using double sided adhesive film. The μSPE column was made in the final step