Bio-inspired surface modification of aluminium heat exchanger fins using laser structuring and PDMS coating for improved and scalable hydrophobic and ice-adhesion performance

With the rapid increase in heat pump installations, the issue of icing on aluminium fins in ASHP has become significant. Ice formation reduces heat exchanger efficiency, leading to higher energy consumption and maintenance costs. To address these issues, we propose the use of DLIP to create bio-inspired structures on aluminium surfaces, followed by applying PDMS via dip-coating to further enhance the hydrophobic and anti-icing properties. The untreated and treated samples were tested for ice adhesion, dynamic and static contact angles before and after ice adhesion, and PDMS coating on the sample surface was observed with sem. DLIP treated surfaces showed significantly increased static contact angles, while the subsequent PDMS coating further reduced ice adhesion. SEM characterization revealed the line-like surface structures inspired by scallop shells with a periodic distance of 18 µm inspired by lotus leaves. The modified surfaces significantly increased the hydrophobicity compared to non-structured Al surfaces for about 40° while maintaining the low ice adhesion strength of 400 kPa, suggesting potential applications for optimizing heat pump efficiency.