Biomimetic Antigravity Water Transport and Remote Harvesting Powered by Sunlight

Fabricated advanced textile for personal thermal management, intelligent health monitoring and energy harvesting

Fabrics are soft against the skin, flexible, easily accessible and able to wick away perspiration, to some extent for local private thermal management. In this review, we classify smart fabrics as passive thermal management fabrics and active thermal management fabrics based on the availability of outside energy consumption in the manipulation of heat generation and dissipation from the human body. The mechanism and research status of various thermal management fabrics are introduced in detail, and the article also analyses the advantages and disadvantages of various smart thermal management fabrics, achieving a better and more comprehensive comprehension of the current state of research on smart thermal management fabrics, which is quite an important reference guide for our future research. In addition, with the progress of science and technology, the social demand for fabrics has shifted from keeping warm to improving health and quality of life. E-textiles have potential value in areas such as remote health monitoring and life signal detection. New e-textiles are designed to mimic the skin, sense biological data and transmit information. At the same time, the ultra-moisturizing properties of the fabric's thermal management allow for applications beyond just the human body to energy. E-textiles hold great promise for energy harvesting and storage. The article also introduces the application of smart fabrics in life forms and energy harvesting. By combining electronic technology with textiles, e-textiles can be manufactured to promote human well-being and quality of life. Although smart textiles are equipped with more intelligent features, wearing comfort must be the first thing to be ensured in the multi-directional application of textiles. Eventually, we discuss the dares and prospects of smart thermal management fabric research.

Bioinspired Self-Standing, Self-Floating 3D Solar Evaporators Breaking the Trade-Off between Salt Cycle and Heat Localization for Continuous Seawater Desalination

Facing the global water shortage challenge, solar-driven desalination is considered a sustainable technology to obtain freshwater from seawater. However, the trade-off between the salt cycle and heat localization of existing solar evaporators (SE) hinders its further practical applications. Here, inspired by water hyacinth, a self-standing and self-floating 3D SE with adiabatic foam particles and aligned water channels is built through a continuous directional freeze-casting technique. With the help of the heat insulation effect of foam particles and the efficient water transport of aligned water channels, this new SE can cut off the heat transfer from the top photothermal area to the bulk water without affecting the water supply, breaking the long-standing trade-off between salt cycle and heat localization of traditional SEs. Additionally, its self-standing and self-floating features can reduce human maintenance. Its large exposure height can increase evaporation area and collect environmental energy, breaking the long-standing limitation of solar-to-vapor efficiency of conventional SEs. With the novel structure employed, an evaporation flux of 2.25 kg m^-2 h^-1 , and apparent solar-to-vapor efficiency of 136.7% are achieved under 1 sun illumination. This work demonstrates a new evaporator structure, and also provides a key insight into the structural design of next-generation salt-tolerant and high-efficiency SEs.

Designing a solar interfacial evaporator based on tree structures for great coordination of water transport and salt rejection

Solar interfacial evaporation has been receiving increasing attention but it is still a huge challenge to achieve excellent coordination between efficient water transport and salt rejection. Here, unlike the common wood-inspired evaporators with equal-diameter directional pores, we have constructed an integrated structure with highly connected gradient pores that mimic the xylem vessels and phloem sieve tubes found in trees. The bio-inspired structure can reduce the resistance of water transport and salt rejection in the same channel. The average transport speed of the 6.5 cm high (2 cm in diameter) porous structure reached 1.504 g s^-1, and water was transported 16 cm after 100 seconds. Using multilayer graphene oxide as the photothermal conversion material, the evaporators with different heights can work for more than 9 hours under the condition of 1 sun illumination and 23 wt% brine without any salt crystallization, and the evaporation rates range from 3.28 to 4.51 kg m^-2 h^-1, with the highest energy utilization efficiency of about 80%. When used in heavy metal treatment, the rejection was greater than 99.99%. This research provides a simple but innovative design idea for evaporators and is expected to further expand the application of solar interfacial evaporation.

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

Water treatment consumes lots of energy from fossil fuels nowadays, and the emission of CO₂ enhances the temperature on earth, resulting in more and more hazards. Thus, clean water production enabled by green energy without CO₂ emission is attracting more and more attention. Herein, we propose a novel solar evaporation system achieving both solar evaporation and water storage with two different unique hydrogels based on a three-dimensional (3D) printing technique. The hydrogel absorber demonstrates an ultrahigh absorptance (98.2%) of solar light, while the water-storage hydrogel absorbs more than 100 times its own weight of water, demonstrating super water-storage performance with strong self-adhesiveness. The solar vapor generation rate can be as high as 3.14 kg·m^-2·h^-1, with a solar evaporation efficiency up to 91.2% irradiated by 1.43 sun. Furthermore, our environmentally friendly solar evaporation system achieves ultrahigh water purification efficiency of 99.99% for salt, heavy ions, and acid/alkaline with remarkable stability and durability. Our solar evaporation system promises long-lasting applications for the hydrological cycle enabled by solar energy, such as seawater desalination, sterilization, wastewater purification, and so on.

A bioinspired solar evaporator with a horizontal channel-like framework for efficient and stable high-salinity brine desalination

In recent years, solar steam generation has been one of the most promising and sustainable techniques for water desalination. However, the heat loss to bulk water dramatically decreases the evaporation rate. Besides, salt deposition on the evaporation surface during brine treatment limits the long-term operation of evaporators. Herein, solar evaporators with a horizontal channel-like framework are reported and high efficiency and outstanding salt resistance are achieved. Firstly, eggplants with a hollow fiber alignment structure were carbonized as CEP evaporators. The CEP-H evaporator with a horizontal fiber growth direction shows a high evaporation efficiency of 90.6% and excellent salt resistance when treating high-salinity brine (20 wt%). The low thermal conductivity perpendicular to the fiber growth direction impedes the conductive heat transfer into bulk water, and fast water transport along the fiber growth direction is beneficial for salt resistance. In addition, a proof-of-concept evaporator polypyrrole-coated polypropylene hollow fiber membrane with a horizontal channel-like framework (PPy/PP-H) has also been developed. This hollow fiber membrane shows a high evaporation rate of 1.64 kg m^-2 h^-1 due to multiangle evaporation and also demonstrates excellent salt-resisting performance for high-salinity brine treatment (20 wt%). The study demonstrates the effect of the horizontal channel-like framework for high evaporation performance and salt resistance, providing new insights into the solar evaporator design for seawater desalination and wastewater treatment.