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ABSTRAK Nur Hasyyati Luqiyana
PUBLIC Irwan Sofiyan

Atmospheric water is a reliable, sustainable source of freshwater. One method that can extract the atmosphere's water content is the atmospheric water generator (AWG) technology, which uses a thermoelectric cooler as the cooling medium (TEC-based AWG). TEC-based AWG has advantages which are a simpler setup and a low carbon footprint. However, there are limitations when using the TEC-based AWG, such as low condensate that can be produced, resulting in high unit power consumption (UPC) and low water harvesting rate (WHR) values. Therefore, in this study, the condensation surface used in TEC-based AWG is modified into a superhydrophobic surface to overcome the issue. This superhydrophobic surface improves heat transfer and droplet removal, increasing the WHR value. Fabricating the superhydrophobic surface involves wet chemical etching and Polydimethylsiloxane (PDMS) coating. Wet chemical etching produces a rough surface that forms a hierarchical structure when examined under a microscope, and PDMS coating using spin method lowers the surface energy of the etched copper. This superhydrophobic surface was created by optimizing the fabrication process's parameters, i.e., liquid etching temperature, etching duration, and spin coater rotation speed. As a result of fabricating optimization, surfaces that were created have contact angles (CA) near 180°, contact angle hysteresis (CAH), and slide angles (SA) close to 0°, preventing droplets from adhering to the surface. According to the experiment results of the TEC-based AWG, the condensate produced by optimized superhydrophobic surface is higher than that of previous research. The optimized superhydrophobic surface, when compared to prior experiments, showed a 4% increase in WHR to 1129.17 g/h and a 15% decrease in UPC value to 15.02 Wh/????2. Considering that the previous research was carried out in a room with a higher relative humidity than the current research, it is predicted that the WHR value will increase under similar humidity levels. Water droplets jumping off the surface occurred on the optimized superhydrophobic surface, which enhanced heat transfer and increased the quantity of produced condensate. Moreover, when TEC-based AWG tests were conducted at various relative humidity levels, the experiment's results indicate that the superhydrophobic surface performs better than the polished copper at a lower relative humidity level. These research results are expected to offer guidelines for improving the performance of TEC-based AWG devices and enhancing produced condensate, especially at low humidity level areas. Furthermore, the fabrication method for superhydrophobic surfaces is expected to help researchers in other fields that require increasing heat transfer and droplet removal rates.