Flexible Sensing Skin for Simultaneous Measurement of Wall Shear Stress, Flow Direction and Dynamic Pressure

A flexible sensing skin has been developed for aircraft surfaces to enable the simultaneous measurement of wall shear stress, flow direction, and dynamic pressure. Three types of sensitive unit structures are designed based on the measurement mechanisms and manufactured using microelectro-mechanical system processes. All sensitive units are flexible and distributed on the surface, enhancing sensitivity and frequency response. Gold is used to create the wall shear stress and flow direction sensitive units, achieving errors of less than 0.4 Pa within the wall shear stress range of 0 to 17 Pa, and directional errors of less than $3^{\circ}$. Polyvinylidene fluoride film is positioned above the chamber to effectively respond to dynamic pressure within the frequency range of 230 Hz to 7800 Hz, covering typical flow characteristics and indicating high sensitivity. The development of the flexible sensing skin provides a novel approach for flow sensing and monitoring on aircraft surfaces.