An aerosol sensor for PM1 concentration detection based on 3D printed virtual impactor and SAW sensor

Abstract

This paper reports an aerosol sensor for PM1 monitoring based on a virtual impactor (VI) and a surface acoustic wave (SAW) sensor. The VI is fabricated using three-dimensional (3D) printing techniques for PM1 classification and a SAW sensor is put at the VI major flow outlet to detect PM1 particles mass. The pressure and flow distribution of the VI and their effects on particles classification have been simulated to optimize the VI structure. In order to enhance surface adhesion for capturing particles, a layer of glycol film is coated on the sensor surface by the atomization method. The aerosol sensor performance is verified through separation and detection of commercial silicon dioxide particles with diameter in the range of 0.1–4 μm. The experimental results show that after classification by the virtual impactor, most of particles in the major flow are PM1 particles and the resonant frequency of the SAW sensor presents a linear decrease trend with the increment of PM1 mass. Moreover, the aerosol sensor has good repeatability and measurement accuracy, and shows high sensitivity of 7.446 Hz/min per μg/m3.