Hybrid pattern surfaces for improved fog harvesting efficiency
Inspired by the fog harvesting capacity of a wettability gradient pattern on the back of Stenocara beetles, researchers have provided a facile and low-cost method for the fabrication of hybrid superhydrophobic–hydrophilic pattern surfaces, with smooth aluminum alloy substrate as the hydrophilic component and superhydrophobic sticky paper of varying hole sizes as the superhydrophobic component. The fog harvesting efficiency was evaluated by adjusting and combining the hole size of the hybrid superhydrophobic–hydrophilic pattern surfaces.
Enhanced fog harvesting efficiency
The prepared single aperture hybrid superhydrophobic–hydrophilic pattern surface exhibit an enhanced fog harvesting efficiency compared with the uniform superhydrophobic and hydrophilic surfaces. Furthermore, the fog harvesting efficiency of the prepared combined aperture hybrid superhydrophobic–hydrophilic pattern surface is 88.3 % higher than that of the single set-up. As the researchers point out, the dynamic fog harvesting mechanism demonstrates that the optimal combined aperture hybrid surface maximises the number of coalesced droplets within a certain period to collect additional water droplets, thus optimising the fog harvesting efficiency. The fog harvesting efficiency reaches a maximum of 362.5 mg/cm2/h.
The study has beeen published in Progress in Organic Coatings, Volume 171, October 2022.