This paper studies the effect of thin film thickness on visibility readout from an interferometric pressure sensor. Interference fringes between a silicon nitride diaphragm and a glass substrate are formed as a function of pressure and can be captured using a camera. Image processing software was used to analyze and correlate the fringe pattern to pressure. Visibility of the interference fringes is optimized by depositing a thin silicon nitride layer on the glass substrate of the sensor using plasma enhanced chemical vapor deposition (PECVD). Optimal visibility was obtained with a coating thickness of 79 nm. Visibility was increased by 150% in comparison to no coating.
Volume Subject Area:
Biomedical Equipment, Medical Robotics/Devices
Topics:
Optimization,
Pressure measurement,
Pressure sensors,
Coating processes,
Coatings,
Glass,
Plasma-enhanced chemical vapor deposition,
Pressure,
Silicon nitride ceramics,
Computer software,
Diaphragms (Mechanical devices),
Diaphragms (Structural),
Diffraction patterns,
Image processing,
Sensors,
Thin films
This content is only available via PDF.
Copyright © 2018 by ASME
You do not currently have access to this content.
