Straight silicon tube for density and mass flow sensing (fabrication, modeling and evaluation)

Abstract

The aim of this project work is to fabricate and evaluate a resonating silicon tube as a density and a Coriolis mass flow sensor. This project consists of three course works: a project work, a microelectronics project, and a master thesis. At first, the licenses needed to work with the clean room facilities were obtained. Several process steps were optimized/calibrated and finally, the first prototypes were fabricated. The fixtures and the electrodes were prepared. A quantitative model for the density/Coriolis mass flow sensor was derived. Several parameters like density sensitivity, pull-in-voltage, Q-factor, resonance frequency, burst pressure, the amplitude of Coriolis effect were investigated/formulated/calculated. An electrical-optical setup was prepared to evaluate the tube as a density sensor. The first three vibration modes were calibrated and the important parameters of a densitometer, quality factor and fluid density sensitivity, were measured. Several sources of loss were investigated. The effect of viscosity and flow were investigated and finally, the results were published in a journal paper and two conference papers. An optical-electrical setup was designed and implemented to detect the Coriolis effect using geometrical optics and MATLAB calculations. Detecting this effect and evaluating the mass flow sensor are the next steps.