Characterization and Design Evaluation of Membrane-Based Calorimetric MEMS Sensors for Two-Dimensional Flow Measurement

This article concerns membrane-based thermoelectric flow sensors that measure both velocity and angle in a plane. The sensor chip was fabricated using a micromachining process. The chip consists of a heater and four thermopiles embedded in a low-stress silicon nitride membrane. The main application for these devices is measuring the airflow distribution in cooled storage rooms. However, their small size of 2 mm by 2 mm, combined with their high angular resolution of less than 0.5°, opens up a spectrum of various applications. Within this work, different heater and thermopile arrangements are presented and compared with each other to reveal the advantages and disadvantages of each design.