3D Flexible Wind Sensor With Its Optimization and Environmental Effect

This paper proposes a new three-dimensional (3D) flexible wind sensor by utilizing dual-layer differential capacitors. The deformation of the sensor caused by wind leads to eight capacitances variation, which can be applied to obtain the wind speed along the x, y, and z axes (v(x), v(y) and v(z)). Consequently, the 3D wind speed and direction are calculated by the vector synthesis. The feasibility of this measurement principle was verified by simulation. Then, the sensor was fabricated consisting of two windward pillar, four electrode layers, and two supporting layers, which were produced by polydimethylsiloxane (PDMS) with different Young's modulus. Experiments demonstrated that the sensor can measure 3D wind speed and direction with the dynamic range of 0-23.9m/s. The average errors of wind speed measurement in XY, XZ and YZ planes are close to 0.58 m/s, 0.42 m/s, and 0.53 m/s, respectively, while the average errors of wind direction measurement are about 6.63 degrees, 4.03 degrees, and 5.65 degrees respectively. Furthermore, temperature effect, as well as humidity effect, of the sensor was also investigated. The initial capacitances of the sensor are positively correlated with the temperature and humidity, and the slope are on the order of 6.21fF<middle dot>degrees C-1, 3.21fF<middle dot>%RH-1, respectively. Moreover, trenches were fabricated to optimize the sensor's sensitivity, which has been verified by experiments.