Highly sensitive resonant pressure sensor based on mode-localisation effect

A novel micro-silicon resonant pressure sensor with two mechanically coupled resonators is presented. When pressure acts on the diaphragm, the perturbed stress will cause stiffness perturbation, leading to mode-localisation phenomenon. Therefore, pressure can be sensed by measuring the amplitude ratio shift. This novel structure is achieved by fabrication on silicon-on-insulator wafer. The measured result shows that the relative amplitude ratio shift (86,819.9 ppm/kPA) is 197.5 times higher than the shift in resonance frequency (439.6 ppm/kPA).