Pressure sensors based on air-coupled resonators

Resonant sensors leverage the dependence of a mechanical resonator’s resonance frequency on some physical parameter affecting the resonator. Squeeze-film pressure sensors comprise a gas chamber that is compressed and expanded by the vibration of a plate resonator. The cavity behaves like a spring attached to the resonator, inducing a resonance frequency shift that depends on the gas pressure. This project focuses on developing a new type of pressure sensor based on this principle. In this case, a pair of piezoelectric plate resonators are coupled by the pressure changes developed in a cavity common to both resonators. The air coupling will create an interaction between the vibration modes of both plates that can be harnessed to determine the pressure.

Assignment

• Perform a literature review on pressure sensors and MEMS resonators.
• Design, simulate and optimize piezoelectric mechanical plates subjected to squeezed film loading and coupled through air cavities.
• Fabricate the designed devices, using the fabrication tools already available at EKL.
• Characterize the resulting devices with electrical and optical measurements. Determine the sensitivity of the different vibration modes to changes in pressure.

Requirements

You must be motivated to learn and apply different techniques for fabricating new devices. Notions of mechanical resonators is desirable. Experience with FEM simulation packages such as Comsol is a plus.

[1] Dolleman, R. J., Davidovikj, D., Cartamil-Bueno, S. J., van der Zant, H. S., & Steeneken, P. G. (2016). Graphene squeeze-film pressure sensors. Nano letters, 16(1), 568-571.

[2] Kumar, L., Reimann, K., Goossens, M. J., Besling, W. F., Dolleman, R. J., Pijnenburg, R. H., ... & Steeneken, P. G. (2015). MEMS oscillating squeeze-film pressure sensor with optoelectronic feedback. Journal of Micromechanics and Microengineering, 25(4), 045011.

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Last modified: 2022-04-08