Frequency Dynamics of Micro-Perforated Thermal Sensors: Unlocking Potential in Acoustic Sensing

This work presents a detailed study on dynamic behavior and the bandwidth (BW) variation of perforated membrane based thermal acoustic sensors using a dual frequency tuning approach. We investigate the physical parameters affecting the two different frequency limitations are investigated, and their dependence is demonstrated and verified through simulation and measurements for two distinct sensor designs. The BW is increased from 55 to 105 Hz by reducing the critical dimensions, demonstrating precise control through adjustments of back volume and thermal mass. The findings highlight the sensor's versatility, enabling tailored performance for narrowband applications such as infrasound monitoring, photo acoustic gas sensing, and enhanced acoustic noise suppression, making it adaptable to diverse acoustic environments and specialized sensing needs.