Columns are considered to be the heart of Gas Chromatography system as it physically separates compounds into separate components. This separation is based on mass transfer between stationary phase (coating on surface of column) and mobile phase (carrier gas). Our group has been active in both development of new designs and novel coating techniques for columns. Apart from our work on open tubular and multi-capillary columns (similar to conventional columns), we have invented new class of micro gas chromatography columns named semi-packed. These types of columns have been reported to increase sample capacity and column efficiency compared to regular capillary columns of similar dimensions. Moreover, by merging micro fabrication with nanotechnology, we have shown that more uniform, robust and reproducible stationary phases can be produced for MEMS columns.