Fabrication and Testing of Polymer Cantilevers for VOC Sensor

The mode dependences of resonance frequencies and quality factors in a PMMA (polymethyl methacrylate) cantilever and a PC (Polycarbonate) cantilever at atmospheric pressure are investigated to obtain fundamental data for polymer-based VOC (volatile organic compounds) sensors. The PMMA cantilever and the PC cantilever are fabricated using hot embossing, bonding and polishing techniques. The resonance frequencies and the quality factors are found to vary largely depending on the vibration mode. The measured resonance frequencies correlate well with the theory of undamped resonance frequency of a flexural-vibrating cantilever. The measured quality factors varied from less than 20 to more than 100 depending on the vibration mode. A higher mode tended to exhibit a higher quality factor. The highest quality factor of 100 was obtained on the 4th flexural mode in both the PMMA and PC cantilever.