Slippery Liquid-Infused Porous Surfaces (SLIPS) with Low Ice Adhesion Developed using Suspension Plasma Spray (SPS)

In-flight ice accumulation on the aerodynamic surfaces of aircraft is one of the major threats facing aerospace companies. A potential solution to alleviate the problems caused by aircraft icing is the development of a slippery surface that can delay ice build-up and facilitate its removal. In this work, using suspension plasma spraying of a submicron-sized TiO2 feedstock particles, porous microstructured coatings has been developed which comprises pillars of approximately 50 - 200 µm in height. These surfaces are impregnated using various lubricating liquid where the micro-pores can act as liquid reservoirs. The resulting solid/liquid interfaces are exceptionally slippery with water contact angle hysteresis as small as 2° which allow water droplets to slide on the surface with minimal energy dissipation. Icing tests in an icing wind tunnel showed icing mitigation, lowered ice adhesion and reasonable durability. Different types of liquid with various properties have been used to impregnate the coating to determine the best performance and durability at different icing/deicing conditions. Additionally, confocal laser microscopy and scanning electron microscopy have been used to study the microstructure and microtexture of the coatings as well as liquid penetration in the pores and oil depletion after coatings have been tested in icing conditions.