Particle sensor for air pollution monitoring

Particulate matter suspended in air has become a threat of major concern for citizens and public health authorities, causing millions of deaths every year and an important economic burden. Sensors integrated on personal devices like smartphones are called to revolutionize the way we characterize and mitigate this type of pollution.

Acoustic delay lines can be used for this purpose, by monitoring the mass deposited on the device. The transit time between two acoustic transducers on a piezoelectric material is related to the amount of mass deposited in the transmission path [1]. However, these devices can detect mass deposition with picogram resolution, not sufficient to detect the landing of single nanoparticles. To improve the mass resolution, the propagation medium for the acoustic wave can be made thinner [2]. In this project, you will design, fabricate and characterize acoustic delay lines on a thin film of piezoelectric material. The goal is to achieve mass resolution in the femtogram range to detect nanoparticles suspended in air.

[1] Wang, Y., Wang, Y., Liu, W., Chen, D., Wu, C., & Xie, J. (2019). An aerosol sensor for PM1 concentration detection based on 3D printed virtual impactor and SAW sensor. Sensors and Actuators A: Physical, 288, 67-74.

[2] Manzaneque, T., Lu, R., Yang, Y., & Gong, S. (2019). Low-loss and wideband acoustic delay lines. IEEE Transactions on Microwave Theory and Techniques, 67(4), 1379-1391.

Assignment

• Perform a literature review on the existing acoustic devices for mass sensing.

• Design, simulate and optimize acoustic delay lines.

• Fabricate thin-film acoustic delay lines, using the fabrication tools available at EKL.

• Characterize the devices with electrical measurements, and under particle exposure (at external facilities in TNO).

Requirements

You must be motivated to learn and apply different techniques for microfabrication in cleanroom.

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Last modified: 2024-02-05