Bio-inspired artificial hair flow sensors: a comprehensive review of design, fabrication, enhancements, and applications.

Flow measurement is critical in various sectors, including industry, agriculture, medicine, and environmental monitoring. There is a growing need for compact, sensitive, scalable, and energy-efficient flow sensors, particularly for applications in unmanned aerial vehicles, unmanned underwater vehicles, biomedicine, and bionic robotics. Inspired by biological mechanosensory structures, artificial hair and hair cell flow sensors have emerged as promising solutions. This study offers a comprehensive review of the progress, underlying principles, performance optimization techniques, and applications of hair flow sensors. We provide an overview of the biological mechanisms of hair as mechanical receptors. Subsequently, we explain the design and fabrication techniques of artificial hair flow sensors, highlighting the challenges associated with replicating and integrating hair structures. The study further explores strategies for sensor enhancement and their diverse applications. Finally, we conclude by outlining the challenges and prospects of hair sensor technology, along with its potential to address specific flow-sensing requirements. While most applications of artificial hair cell flow sensors are still in the research stage, they offer substantial potential for flow measurement. Future progress in materials science, structural design, and sensing mechanisms is anticipated to drive the development of these sensors, opening up new avenues for scientific research and commercial applications.