A gasket-type standard leak element using femtosecond laser micromachining

A gasket-type standard leak element with a microfluidic channel was developed and measured. The microfluidic channel with a diameter of several micrometers and a length of one hundred micrometers was fabricated by using femtosecond laser micromachining. The conductances (<1 × 10−6 L s−1) of the microfluidic channel for various non-condensable gases -- H2, He, CH4, N2 and CO2 were determined by a measuring system based on conductance modulation (CM) method. The experimental results show that the flow characteristics of our devices exhibit molecular flow at a pressure up to 100 mbar and the conductance values of H2, He, CH4, N2 and CO2 are inversely proportional to the square root of their molecular mass.