Affiliations: [a] College of Mechanical Engineering, Yangzhou University, Yangzhou 225127, Jiangsu, China | [b] College of Mechanical & Electrical Engineering, Qingdao University, Qingdao 266071, Shandong, China
Correspondence:
[*]
Corresponding author: Yixiang Bian, College of Mechanical Engineering, Yangzhou University, Yangzhou 225127, Jiangsu, China. E-mail:yxbian@yzu.edu.cn
Abstract: Crickets and many other orthopteran insects can detect an impinging airflow
using mechanosensory hairs located on their cerci. Inspired by these
filiform mechanosensory hairs, a new symmetrical electrodes metal-core
piezoelectric fiber (SMPF) was designed and fabricated as a building block
for future airflow sensors. This novel type of airflow sensor was produced
utilizing the extrusion method and high-temperature sintering. A metal core
was basically located at the center of the fiber and surrounded by a hollow
cylinder of ceramic material. Two thin metal films were spray-coated
symmetrically on the surface of the fiber on opposite sides. After
successful polarization, the two surface metal layers could be used as
sensor electrodes. This way, a cantilevered SMPF was able to detect the
strength and direction of an impinging airflow. A theoretical model of the
SMPF airflow sensor was established and validated by the experimental
results. The results further showed that the electric charge generated on
the electrodes of a cantilevered SMPF grows exponentially with the airflow
strength, and that it is proportional to the cosine of the airflow
direction.
Keywords: Bio-inspired, piezoelectric fiber, airflow sensor, directional response, metal core
