Waterproof, Anti‐Impacted, and Ultrathin Carbon‐Based Air Pressure Sensors Toward Aerodynamic Tests on High‐Speed Trains

Air pressure sensors play a crucial role in aerodynamic tests on high‐speed trains, especially when the aerodynamic problems become more significant when the speed of high‐speed trains increases. The air pressure sensors used for aerodynamic testing of high‐speed trains are currently based on microelectromechanical systems (MEMS), which are thick, difficult to adjust linear range, and easily damaged by overloading force and water, thus cannot satisfy all‐weather train aerodynamic monitoring. Herein, a flexible ultrathin air pressure sensor for aerodynamic testing of high‐speed trains is reported; this sensor is based on a sensing material of carbon fiber beams and a sealed microchamber structure. The microchamber structure model allows the sensor to achieve high sensitivity in the target linear range by adjusting the initial internal pressure of the sealed microchamber. Meanwhile, the sealed microchamber structure enables the sensor to be waterproof and anti‐impacted. The sensor can work in water for at least 500 min and remain undamaged after being run over by a car with a weight of approximately 1550 kg. Furthermore, this air pressure sensor has been successfully applied in real‐time train surface pressure monitoring and shows the fantastic perspective for sensors toward aerodynamic tests on the high‐speed trains.