Structural\nOptimization of Polyimide-Film Humidity\nSensors for New Energy Vehicles

This\npaper presents a comprehensive study of the structural optimization\nof polyimide-film (PI-film) capacitive humidity sensors, with a focus\non enhancing their performance for application in new energy vehicles\n(NEVs). Given the critical role of humidity sensors in ensuring the\nsafety and efficiency of vehicle operationsparticularly in\nmonitoring lithium-ion battery systemsthe study explores the\nintricate relationship between the interdigitated electrode (IDE)\ndimensions and the PI-film thickness to optimize sensor responsiveness\nand reliability. Through a combination of COMSOL Multiphysics simulations\n(a powerful finite element analysis, solver, and simulation software)\nand experimental validation, the research identifies the optimal geometrical\ncombination that maximizes the sensitivity and minimizes the response\ntime. The fabrication process is streamlined for batch preparation,\nleveraging the spin-coating process to achieve consistent and reliable\nPI films. Extensive characterizations confirm the superior morphology,\nchemical composition, and humidity-sensing capabilities of the developed\nsensors. Practical performance tests further validate their exceptional\nrepeatability, long-term stability, low hysteresis, and excellent\nselectivity, underpinning their suitability for automotive applications.\nThe final explanation of the sensing mechanism provides a solid theoretical\nfoundation for observed performance improvements. This work not only\nadvances the field of humidity sensing for vehicle safety but also\noffers a robust theoretical and practical framework for the batch\npreparation of PI-film humidity sensors, promising enhanced safety\nand reliability for NEVs.