Micro Quartz Tuning Fork-Based PM2.5 Sensor for Personal Exposure Monitoring

A portable, wireless, and cost-effective PM2.5 sensor based on micro quartz tuning fork (MQTF) has been developed. Coated with repositionable polymer glue for effective absorption of PM2.5 and with the help of innovative nozzle inlet, the MQTF-based sensor is highly sensitive to PM2.5 in the detection range of 2 similar to 2000 mu g/m(3)ith high stability. The sensor response, change rate of the MQTF frequency, shows linear relationship with PM2.5 concentration from 6 to 100 mu g/m(3) at the flowrate of 1.7 L/min, which is a typical range of PM2.5 concentration in ambient air. By integrating the repositionable adhesive coated MQTF, driving and detection circuit, PM2.5 filter, sampling system, and a smartphone with Bluetooth and home-developed app, the MQTF-based sensor is assembled for personal PM2.5 exposure monitoring. Furthermore, field tests show that the PM(2.5 )concentration readings from MQTF-based sensor and commercial PM monitor correlate very well with each other, which indicates the high accuracy and reliability of the MQTF-based sensor.