A microfluidic porous solid phase suitable for mass production

Porous microstructures are difficult to integrate in MEMS devices under large-scale production conditions. Typically, integration requires time consuming and error-prone operations at chip level that are incompatible with further cleanroom processing. To overcome this obstacle, we present the wafer-level manufacture of porous solid phases for microfluidic applications using a novel MEMS process. The process comprises the introduction of a loose powder into pre-structured cavities on wafer-level and the agglomeration of the powder by atomic layer deposition (ALD). As an application example for integrated porous solid phases, on-chip liquid chromatography for the separation of acetaminophen and gentisic acid is demonstrated.