(Pdf link) hhttps://www.nature.com/articles/s41467-025-65586-2.pdf

Key takeaways:

- Traditional (Solar): Typically limited to 1 cycle per day. Sorbents collect moisture at night and use sunlight to release it during the day. Requires a large horizontal footprint to maximize exposure to sunlight.

- Ultrasonic: Can perform multiple cycles per day. The extraction takes only 2 mins, and the hydrogels used can adsorb moisture in about 40 minutes. This allows the system to continuously cycle 24/7, rather than waiting for the sun. Allows for vertical stacking (e.g., 5+ rows high) without losing efficiency, drastically increasing the water output for the same amount of land area.

- Ultrasonic per day output: 3.25 L (1 layer) to 16.25 L (5 layer)