Development of PMMA-based gas sensor and its evaluation using a VOC dilution flow system

• We have developed and evaluated a PMMA-based gas sensor for monitoring VOCs.
• The sensor consists of a PMMA cantilever, a PVDF piezoelectric film and a PBD.
• The sensor had a resonant frequency of 341 kHz and quality factor of 71.
• We examined the resonant frequency shift by setting up a VOC dilution flow system.
• The resonant frequency shifted when the sensor was exposed to toluene vapor.

We have developed and evaluated a PMMA-based gas sensor to realize a low-cost sensor network system for monitoring VOCs (volatile organic compounds). The PMMA-based gas sensor consists of a PMMA (poly methyl methacrylate) cantilever, a piezoelectric film of PVDF (polyvinylidene fluoride), and a thin film of PBD (polybutadiene). We began by investigating the influence of PBD coating of a dynamic property of the PMMA cantilever in a higher order resonance mode under atmospheric pressure at room temperature. The PBD-coated PMMA cantilever had a resonant frequency of 341 kHz and quality factor of 71 at the 4th flexural vibration mode. Next, we examined the change of resonance frequency in the presence of toluene vapor by setting up a gas sensor evaluation system equipped with a VOC dilution flow system, temperature-controlled chamber, oscillation circuit, and frequency counter. The resonant frequency shifted when the PMMA-based gas sensor was exposed to toluene vapor. The measured toluene sensitivity in the experiment was 0.02 Hz/ppm.

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