Design Of ALN-based MEMS Wind Speed And Direction Integrated Sensor

The weather has been the concern of the people meteorological parameterssuch as temperature, pressure, humidity, water vapor flux, wind direction andspeed, is a very important part of the meteorological data including wind speedand direction measurements in weather forecasting, environmental monitoring,control and other important applications. With the development of MEMStechnology, heat flows Wind Sensor with new breakthroughs and developments.Compared with traditional fluid measuring device, the thermal flow sensor has asmall size, and low cost, is the development direction of the fluid measurement.In this paper, a AlN-based thermal isolation four arrays of hot flow windspeed and direction sensor is designed and produced based on MEMS technology.The main content of the research in this article:1. In this paper, a2D micro structure wind speed and direction sensor ismade on the0.2mm thick AlN substrate by photo lithography process and lasermicromachining process. The sensor consists of an intermediate heater, fourtemperature detectors and a temperature sensor, eight thermal isolation holes isetched between the four temperature probes by laser micro machining to reducethermal conduction losses and increase the effective thermal traffic exchange.2. AlN-based thermal isolation four arrays hot flow wind speed and directionsensor is verified design rationality and process feasibility by ANSYS simulationand performance testing. From analysis, using thermal isolation can effectivelyimprove the sensitivity of the four detectors, reduce the heating electrode powerconsumption and thermal conduction losses, reduced the sensor design size andimprove the integration of the design.3. To change the sensor output resistance to easily measured electricalsignal, a transmission circuit is designed, and the circuit is debugged to complete the performance test and calibration of the multi-meteorologicalparameters sensor.4. The error of wind speed, wind direction measuring by system is analyzedand processed. The sensor design and process are further validated feasible.The designed sensor has small size, low power consumption, easy integrationfeatures, and can be applied to the various portable flow meter and gas flowdetector in complex environment. Sensor test results show that: the maximumangle difference is5°, and the speed error is less than0.5m/s. The powerconsumption is120mW, the response time is less than ten seconds.