Hung Chiao-Fang, Yeh Po-Chen, Chung Tien-Kan
Department of Mechanical Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan.
International College of Semiconductor Technology, National Chiao Tung University, Hsinchu 30010, Taiwan.
Sensors (Basel). 2017 Feb 8;17(2):308. doi: 10.3390/s17020308.
In this paper, we demonstrate a miniature magnetic-force-based, three-axis, AC magnetic sensor with piezoelectric/vibrational energy-harvesting functions. For magnetic sensing, the sensor employs a magnetic-mechanical-piezoelectric configuration (which uses magnetic force and torque, a compact, single, mechanical mechanism, and the piezoelectric effect) to convert -axis and -axis in-plane and -axis magnetic fields into piezoelectric voltage outputs. Under the -axis magnetic field (sine-wave, 100 Hz, 0.2-3.2 gauss) and the -axis magnetic field (sine-wave, 142 Hz, 0.2-3.2 gauss), the voltage output with the sensitivity of the sensor are 1.13-26.15 mV with 8.79 mV/gauss and 1.31-8.92 mV with 2.63 mV/gauss, respectively. In addition, through this configuration, the sensor can harness ambient vibrational energy, i.e., possessing piezoelectric/vibrational energy-harvesting functions. Under -axis vibration (sine-wave, 100 Hz, 3.5 g) and -axis vibration (sine-wave, 142 Hz, 3.8 g), the root-mean-square voltage output with power output of the sensor is 439 mV with 0.333 μW and 138 mV with 0.051 μW, respectively. These results show that the sensor, using this configuration, successfully achieves three-axis magnetic field sensing and three-axis vibration energy-harvesting. Due to these features, the three-axis AC magnetic sensor could be an important design reference in order to develop future three-axis AC magnetic sensors, which possess energy-harvesting functions, for practical industrial applications, such as intelligent vehicle/traffic monitoring, processes monitoring, security systems, and so on.
在本文中，我们展示了一种基于磁力的微型三轴交流磁传感器，它具有压电/振动能量收集功能。对于磁传感，该传感器采用磁-机械-压电配置（利用磁力和扭矩、紧凑的单一机械机构以及压电效应）将x轴和y轴平面内磁场以及z轴磁场转换为压电电压输出。在z轴磁场（正弦波，100 Hz，0.2 - 3.2高斯）和y轴磁场（正弦波，142 Hz，0.2 - 3.2高斯）下，传感器灵敏度的电压输出分别为1.13 - 26.15 mV（灵敏度为8.79 mV/高斯）和1.31 - 8.92 mV（灵敏度为2.63 mV/高斯）。此外，通过这种配置，该传感器能够收集环境振动能量，即具有压电/振动能量收集功能。在x轴振动（正弦波，100 Hz，3.5 g）和z轴振动（正弦波，142 Hz，3.8 g）下，传感器的均方根电压输出及功率输出分别为439 mV（功率为0.333 μW）和138 mV（功率为0.051 μW）。这些结果表明，采用这种配置的传感器成功实现了三轴磁场传感和三轴振动能量收集。由于这些特性，这种三轴交流磁传感器可能成为未来开发具有能量收集功能的三轴交流磁传感器的重要设计参考，用于实际工业应用，如智能车辆/交通监测、过程监测、安全系统等。
