3D‐Printed Bionic Solar Evaporator

Abstract

Solar water evaporation, which can be utilized for seawater desalination and wastewater treatment, promises freshwater security with renewable energy. Herein, a bionic solar evaporator consisting of a hydrogel solar absorber and bionic microchannels fabricated by the projection microstereolithography based 3D printing technique is proposed. Such a bioinspired solar evaporator achieves a fast water self‐transport speed and a high solar water evaporation rate of 4.12 kg·m−2·h−1 under 1 sun irradiation (1 kW·m−2), and the solar thermal efficiency can be as high as 92.1%. However, both the evaporation rate and solar thermal efficiency are greatly affected by properties of the hydrogel, geometric parameters of microchannels, and intensity of the light source. Most significantly, the bionic solar evaporator is applied for wastewater treatment including the purification of organic dyes, acid and alkali, as well as metal ions. The purification rate can be as high as 99.999%, demonstrating amazing performance for clean water production. The bioinspired water evaporator promises applications for solar energy harvesting, photothermal conversion, as well as environmental engineering, such as solar vapor generation, thermophotovoltaic cell, sewage disposal, and desalination of seawater.

A cryogel solar vapor generator with rapid water replenishment and high intermediate water content for seawater desalination

“…Well-designed water management can reduce evaporation enthalpy by increasing the ratio of intermediate water to free water. 27,[31][32][33][34] One strategy to improve water replenishment is to use the direction freezing method 35,36 or 3D printing technique 37 to construct vertically aligned channels within the hydrogels. However, these fabrication methods are cumbersome or timeconsuming, hindering the large-scale fabrication and application of these SVG systems.…”

Super Water-Storage Self-Adhesive Gel for Solar Vapor Generation and Collection

“…), carbon materials (graphene, CNT, etc , multiple materials, and hydrogel materials , have been proposed for solar vapor generation with high evaporation efficiency. Up to date, the evaporation rate of the solar desalination can reach up to 4.12 kg·m –2 ·h –1 with an evaporation efficiency higher than 90% .…”

Three-Dimensional Open Water Microchannel Transpiration Mimetics

“…Natural organisms have evolved unique capillary abilities for survival. − As the smallest bird in the world, hummingbird’s flexible tongue allows them to quickly suck and transport nectar (Figure a) . Since 1883, many studies have focused on their feeding mechanisms and gradually differentiated into two major points: the capillary theory and the elastic micropump theory. , The tongue of a hummingbird is initially cylindrical with a longitudinal slot, which is compressed and dented when it protrudes from the beak.…”