Reliable pressure measurement represents a cornerstone of cryogenic engineering, spanning fields from superconducting magnets and deep-space exploration to cryogenic wind tunnels. However, acquiring accurate in situ data in these extreme low-temperature environments remains a formidable challenge, as conventional sensors typically face material embrittlement, seal failure, and performance degradation. Herein, an all-polyimide (PI) intelligent flexible sensing skin (iFlexSense) tailored for pressure monitoring under extreme environmental conditions was proposed. A novel droplet-encapsulation architecture was designed to enhance sensor sensitivity in the high-pressure working range while preserving its response characteristics in the low-pressure working range. This architecture was implemented via a PI electrospray approach, which also ensured robust interlayer adhesion, thereby maintaining structural and hermetic integrity at temperatures down to −196 °C. Additionally, this flexible skin was successfully validated in cryogenic wind tunnels across a broad operational envelope ( T 0 = 110–300 K, P 0 = 115–450 kPa, M a = 0.6–1.3, where T 0 is the total temperature, P0 is the total pressure, and Ma is the Mach number). Results demonstrated excellent fidelity with data from a standard pressure scanner. The sensing skin effectively captured nuanced aerodynamic phenomena, including Reynolds number effects and shock wave evolution. Collectively, the present work establishes the iFlexSense as a robust, versatile tool for high-fidelity pressure mapping in demanding cryogenic engineering applications.
Yin et al. (Fri,) studied this question.