2014 Volume 1 Issue 5 Pages MN0055
We have developed and evaluated polycarbonate (PC)-based dual cantilever sensors as part of a low-cost sensor network system for monitoring VOCs (volatile organic compounds). The PC-based dual cantilever sensor consists of a PC cantilever and a PBD (polybutadiene)-coated PC cantilever with PVDF (polyvinylidene fluoride) piezoelectric films. We began by investigating the size and mode dependences of resonant frequencies and quality factors of PC cantilevers and PBD-coated PC cantilever as output signal of PVDF piezoelectric film. Next, we examined the change of resonance frequency in the presence of VOCs vapor by setting up a resonance sensor evaluation system equipped with a dilution flow system, temperature-controlled chamber, oscillation circuit, and frequency counter. The resonant frequency of both PC cantilever and PBD-coated PC cantilever shifted significantly downward depending VOCs.