CMOS-MEMS micro sensors using mesoporous carbon immobilized by the dielectrophoresis process for gas detection

A novel class of micro gas sensors using mesoporous carbon powder as the sensitive film is presented for the first time with full CMOS compatibility and MEMS manufacturability. Powdered mesoporous carbon is employed as active sensing layers and deposited between electrodes on a thin membrane where the micro-heater and electrodes are implemented. With employment of the dielectrophoresis (DEP) process, mesoporous carbon is successfully aligned and stacked between Cr electrodes and thus forms an adhesive layer after a dry-up step. Finally, comprehensive gas tests such as N₂, O₂ and CO were proceeded to verily the gas-sensitive characteristics of mesoporous carbon. Experimental results demonstrate that mesoporous carbon powder is promising to offer excellent sensitivity in both oxidizing and reducing gases due to its superior porosity and extensive surface.