A Gas Flow Meter With Linear Sensitivity Based On Freely-Suspended Nanofilms Of Smectic Liquid Crystal

A technique of mechanical airflow sensing based on coupling to a film of fluid smectic liquid crystals is presented. A gas jet confined to a narrow channel induces flow in a continuous, freely suspended film with racetrack geometry, whose velocity field is then mapped using video microscopy and particle tracking techniques. Because the nanofilm has so little mass compared to the air, its velocity provides a direct readout of the velocity profile of the gas in the channel. This method of flow measurement offers several advantages over conventional mechanical flow meters: It has linear sensitivity, and so, it can operate at low flows, and the energy lost due to the measurement is negligible. Published under license by AIP Publishing.