A Multi-Functional VOC Sensor Based on Cascaded Quartz Crystal Resonators

A multi-functional VOC (volatile organic compound) sensor composed of four parallel-connected quartz crystal resonators (QCRs) configured as a cascaded resonator was developed for VOCs identification and quantification. The structure of the cascaded resonator allows the high-resolution output response signals from the four QCRs to be obtained through a single measurement. Multi-parameter responses for each QCR can be calculated to form a hybrid sensor array, combining the advantages of multisensor array (MSA) and virtual sensor array (VSA), significantly enhancing the sensor’s ability to identify both similar and diverse types of VOCs. Results show that the highest sensitivity is 16.14 Hz ppm−1, with the lowest limit of detection is 0.34 ppm, exhibiting excellent sensing performance. Classification accuracy to eight VOCs is 98.68% of the hybrid sensor array. This development is of significant importance for the realization of artificial olfaction.