Micro anemometer by a MEMS compatible lab-on-a-tube technology

This paper reports a novel micro airflow anemometer based on the hot-film sensing principle, i.e. gas cooling of electrically heated resistance. The sensor with three Ti/Pt hot-film sensing components with width of 50μm and thickness of 130nm has been fabricated on a glass tube in a UV lithography system with multi-layer alignment by our developed MEMS compatible lab-on-a-tube technology. The micro anemometer has demonstrated high sensitivity, fast response and ability to detect wind speed and direction. The influence of environment temperature on output voltage when micro anemometer with and without the temperature compensation was evaluated. And the test response time is in the range of milliseconds, also faster than several seconds reported for that in-plane one [1]. In the wind speed and direction field-test, using a commercial ultrasonic anemometer as the reference, achieved mean error of direction is 13.5° and mean error of velocity is 0.02m/s.