An Infrared Chemical Sensor Based on Plasmonic-Enhanced Bulk Acoustic Wave Resonator Array

This letter reports a multi-spectral infrared chemical sensor based on a virtual array of bulk acoustic wave resonators with different frequencies. The plasmonic metasurfaces with different patterns on the top surface of resonators provide high IR absorption without degradation of resonating performance. The metasurfaces enhance the frequency responses of the resonant sensor to the specific infrared by about ten times. In a demonstration, four kinds of polymers and their mixtures were detected by the sensor to show its capability for distinguishing unknown compounds. The proposed chemical sensor shows great potential for fast, accurate and portable infrared spectrum microsystems for chemical composition analysis.