With the rapid rise in heat pump installations in recent years, the issue of icing on aluminum samples used in air sourced heat pump systems has gained significant attention. Ice formation on the heat exchanger located on the outside of the building reduces the efficiency of heat transport; moreover, it results in increased energy consumption and maintenance costs. Thus, developing aluminum samples with anti-icing properties has become an important research direction. Inspired by the surface structure of scallop shells, we propose using laser technology to create scallop shell-like structures on aluminum sheet surfaces to optimize their hydrophobic properties, so that the ice on the sample surface can be easily separated or slide off more easily after melting.

In this study, we initially measured the surface characteristics of untreated aluminum samples, including surface energy, ice adhesion, static and dynamic contact angle. These preliminary results provided a baseline for comparisons. Following this, we used laser processing technology to replicate the ridged structures of scallop shells on the aluminum surface and subsequently performed the same tests on the laser-treated aluminum samples. Results showed that, the static contact angle of aluminum samples after laser treatment significantly increased, indicating greatly enhanced hydrophobicity. Additionally, the slight increase in dynamic contact angle hysteresis with the increase of the cycle number suggested that water droplets move more easily on the surface. The ice adhesion force also varies with different laser treatment methods. To have more understanding of the impact of laser treatment on surface morphology, we performed detailed observations using scanning electron microscopy (SEM). Our results revealed that the laser-treated aluminum surfaces possess regular ridged structures, nearly resembling the surfaces of scallop shells. Additionally, the number and size of the cavities within these ridges are closely related to the ice adhesion force.

This study verifies the effectiveness of bioinspired structures in enhancing the hydrophobic surfaces and demonstrates the great potential of laser technology in surface engineering. It expands the boundaries of biomimetic materials science and provide a basis for optimizing heat pump performance with potential for widespread industrial application.