A 3D-printed miniature gas cell for photoacoustic spectroscopy of trace gases

A new methodology for the development of miniature photoacoustic trace gas sensors using 3D printing is presented. A near-infrared distributed feedback (DFB) laser is used together with a polymer based gas cell, off the shelf fiber optic collimators and a microelectromechanical system (MEMS) microphone to measure acetylene at 1532.83nm. The resonance behavior of the miniature gas cell is analyzed using a theoretical and experimental approach, with a measured resonance frequency of 15.25kHz and a Q-factor of 15. A minimum normalized noise equivalent absorption of 4.5·10-9Wcm-1Hz-1/2 is shown together with a 3σ detection limit of 750 parts per billion (ppb) for signal averaging times of 35seconds. The fiber coupled delivery and miniature cost-effective cell design allows for use in multi-point and remote detection applications