Fabrication of a MEMS-based separation module for liquid chromatography

This work presents the design, fabrication and characterization of a Si-based microseparation module for liquid chromatography (LC), targeted for agrofood applications and in particular for wine quality monitoring. The microsystem chip is a Silicon/Pyrex structure realized by anodic bonding. The basic Si-chip modules are an open tubular microcolumn with inlet/outlet for fluidic connections, a platinum heater and a Pt three-electrode amperometric sensor. Analytical calculations and finite element analysis have been performed to optimize the microcolumn design. Microchannels and inlet/outlet have been fabricated by deep reactive ion etching (DRIE) and tetra methyl ammonium hydroxide (TMAH) wet etching, respectively. The column has been functionalized with n-octyltriethoxysilane (C8-TEOS). Preliminary characterization tests of the microcolumn have been performed by evaluating the capability of the system to retain test solutions of acetic acid.