Source: ioptics  27th Nov 2025

Icing in aero-engines is one of the critical factors threatening flight safety. once ice accumulates on engine air intake systems (e.g., engine casings and inlet lips), the aerodynamic characteristics of the intake will be altered, leading to a significant increase in flow resistance. Mild icing can cause airflow distortion and impair engine operational stability; severe icing may even result in engine flameout and shutdown, with catastrophic consequences. In addition, detached ice debris can be sucked into the engine, causing damage to its components.

Under specific flight and meteorological conditions, icing can occur even in non-snowy weather. For instance, when a large number of supercooled liquid droplets (with temperatures below 0°C) in clouds impinge on the leading edge of the engine nacelle intake, they can still condense into ice, reducing engine air intake volume and degrading performance. However, existing engine anti-icing and de-icing systems (such as bleed-air anti-icing and electric heating anti-icing) come at the cost of certain structural modifications and performance trade-offs. Therefore, it is a crucial industrial demand to endow material surfaces with both superhydrophobic and photothermal properties via surface modification, enabling energy-free anti-icing/de-icing capabilities.

Professor Yao Jianhua's team from Zhejiang University of Technology, in collaboration with AECC Shenyang Liming Aero-Engine Co., Ltd., introduced photothermal agents onto hydrophobic surfaces to impart photothermal performance. Under sunlight or directed laser irradiation, these photothermal agents achieve efficient photothermal conversion, forming an ice-water interface between the ice layer and the surface, which in turn facilitates rapid de-icing by leveraging the surface's low liquid adhesion. The team successfully fabricated hierarchical superhydrophobic photothermal surfaces with honeycomb armor-like features on various substrates including metals, glass, and ceramics using femtosecond lasers.

They investigated the femtosecond laser ablation process for creating hierarchical structures on material surfaces, analyzed the regulation mechanism of processing cycles on structural depth and width, and realized precise control over micro-nano structure dimensions. based on static hydrophobicity and icing delay performance tests, the team optimized the microcolumn structure size and the content of Fe?O? nanoparticles introduced via high-pressure spraying. Results show that constructing a hierarchical micro-nano structure composed of microcolumns, PDMS deposits, and PDMS/Fe?O? nanocomposites can extend the icing delay time by approximately 2.14 times.

Thanks to the synergistic effect between the photothermal trapping effect of the microcolumn structure and the Fe?O? nanoparticles, the surface photothermal performance is significantly enhanced. The maximum surface temperature increased from 40.3°C of the original surface to 72.9°C, representing a relative improvement of about 78.6%.

Superhydrophobic surface anti-icing technology involves complex interfacial contact science. Key issues such as the wetting mechanism of surface structures under different environments, and how to obtain anti-icing surfaces that meet long-term outdoor service performance requirements, remain to be further studied. Moving forward, the team will conduct ultraviolet aging tests, extreme humid-heat environment tests, and repeated freeze-thaw cycle tests to further evaluate the attenuation characteristics of surface anti-icing performance under outdoor service conditions.

Institute of Laser Advanced Manufacturing, Zhejiang University of Technology