TECHNOLOGY FOCUS - POLYMERS - Preferred Process: The PDMS porous membrane is formed by creating a mold master, pouring a PDMS liquid precursor over the mold master, allowing the PDMS liquid precursor to cure, and removing the PDMS porous membrane from the mold master. It may be formed by extruding a sheet of PDMS with a thickness of 25-100 mum, forming a metal layer on the PDMS sheet by photolithographic techniques, patterning holes in 5-25 mum in the metal layer, and etching using reactive ion etch techniques. The creation of a master mold is accomplished by micromachining or by photopatterning an epoxy, preferably SU-8. Attaching the PDMS porous membrane to the MEA involves performing a surface preparation step on the surface of the microfluidic molded structure prior to bonding the PDMS porous membrane to the molded structure.The surface preparation step involves cleaning with a solvent preferably ethanol and irradiating with an oxygen plasma. The mold master comprises silicon. Removing the cured material from the mold master is performed by submerging the mold and the attached PDMS in an alkaline hydroxide bath to remove the silicon. It is released by submerging the mold and the attached PDMS in an acetone bath to remove the photoresist.Bonding the cured material to the microfluidic molded structure involves cleaning both surface of the PDMS porous membrane and the surface of the organic material with a solvent, heating the organic material to 120degreesC for 10 minutes, placing the organic material in a boat comprising a material that allows the organic material to absorb heat, submerging the organic material in a surface bonding agent for 1 minute, plasma etching both the organic material and the PDMS porous membrane in oxygen plasma for 1 minute at 100 watts, and placing together the PDMS porous membrane and the organic material immediately following the etching step. Forming the embedded metal structure comprises rinsing the surface of the PDMS material with a solvent, plasma etching the surface of the PDMS material, forming an adhesion layer onto the surface of the plasma-etched substrate, evaporating a metal layer onto the adhesion layer, and patterning the metal layer. The adhesion layer is preferably chromium and is applied to a thickness of 200 Angstrom.Preferred Materials: The liquid precursors are SYLGARD 184 or the product SYLGARD 186. The microfluidic molded structure consists of silicon, PDMS, ceramic, or plastic. It comprises an organic material preferably acrylic. The boat comprises plastic.