Tailoring silicon for dew water harvesting panels

Abstract

Unusual condensation dynamics occur on the hierarchical Black Silicon metasurfaceNear-zero water removal time and good water yield are simultaneously achieved Great scalability and multifunctionality are accessible to the proposed water panel

Water Harvesting from Air: Current Passive Approaches and Outlook

“…Left and right insets are photographs of the droplet jumping and sweeping motion modes, respectively. [Reproduced with permission from ref . Copyright 2021, Cell Press.…”

“…It can be fabricated by femtosecond laser irradiation − or physical/chemical etching. − After appropriate surface modification, the needle-shaped morphology results in the “truly superhydrophobic” surfaces, − which allows not only a large contact angle (>150°) but also a small contact angle hysteresis (the difference between advancing and receding contact angles). The condensed droplets can easily detach from such a surface through sweeping or jumping . The former is caused by the droplet in-plane coalescence and the neighboring droplets along sweeping motion track will be taken away by the shedding large droplet, resulting in remarkably fast water removal and surface refreshing abilities .…”

“…The latter is induced by the droplets out-of-plane coalescence, − which occurs at the very early stage of condensation and assists the removal of small droplets, contributing to the water collection and the reduction of evaporative loss Figure e displays the excellent water harvesting capacity and very fast droplet removal of the reported black silicon . On the other hand, by virtue of the combined effect of surface topography and dopant elements, black silicon is also able to achieve ultrabroadband absorption enhancement even exceeding 90% in the atmospheric window, leading to the potential radiative cooling ability .…”

“…To provide portable water is one of the most common targets for AWH devices. Through surface morphology optimization, a 1 m 2 dew condensation panel is able to generate more than 1 L of drinkable water per night . Furthermore, each kg of MOF-801 material can generate 2.8 L water daily in an arid environment (RH ≤ 20%), which even satisfies the water demand of an adult in the desert .…”

Efficient fabrication of tilt micro/nanopillars on polypropylene surface with robust superhydrophobicity for directional water droplet rebound

“…The collision and contact process between water droplets and a solid surface is a dynamic physical phenomenon that occurs at the solid-liquid-gas interface between three phases ( Wu et al., 2011 ). During the collision process, the contact wetting status between the water droplets and solid surface plays a dominant role in the applications of microfluidics, drug delivery, oil-water separation, anti-fog water collection, and printing ( Liu et al., 2021 ; Lu et al., 2022 ; Mi et al., 2019 ; Whitesides, 2006 ; Yarin, 2006 ; Zhou et al., 2020 ; Wang et al., 2022a , 2022b ). Nevertheless, the uncertainty of water droplet bounce limits its further development in these fields.…”