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With the development of human society and economy, the problem of energy shortage has become increasingly prominent. Because traditional fossil energy reserves are limited, non-renewable and cause environmental pollution in the process of utilization, the use of clean energy is considered to be the only way for human development. As a clean and sustainable energy source, solar energy has always been valued. The traditional bulk heating, due to the lower conversion efficiency (30%–50%) caused by optical and thermal loss, limits the further development and promotion of the technology. In recent years, the concept of interface solar vapor conversion has been proposed. The interface solar vapor conversion which means that with the micro-nanostructure design and effective optical and thermal control, sunlight is fully absorbed and its energy is transmitted to the water molecules only at the interface between water and air, so that the liquid is continuously converted into vapor and the heat loss of high-temperature absorbers to large bodies of water and radiation loss to the air are reduced. Therefore, to achieve effective solar-vapor conversion, there are many requirements for the absorber: (1) the absorber materials need to be kept on the surface of the water; (2) the absorber needs to have sufficient solar absorption rate; (3) the absorbed energy needs to be effectively heated the water layer in contact with the absorber, thereby achieve the water to vapor conversion process quickly and efficiently. With the advancement of research, a series of new materials and new structures have been proposed, which effectively solve the problem of optical absorption loss and thermal loss of absorbers to insure the adequate water supply, resulting in a significant increase in conversion efficiency (>90%). In this review, we describe the mechanisms of interface solar vapor conversion, including light absorption, thermal management, and water supply, and demonstrate recent advances in energy conversion efficiency through a series of micro- and nano-structured material designs. Then we introduced some of the major applications currently based on interface solar vapor conversion, including seawater desalination, sewage treatment, etc. We demonstrate some typical research with excellent salt rejection for these applications. Finally, we look forward to the future development of the interface solar vapor conversion. We pointed out several problems that need to be solved to further improve the energy conversion efficiency. With the resolution of these problems, the photo-thermal conversion efficiency is expected to reach 100%, and the cost can be further reduced which indicates a huge application market and research prospects in this field.

Bi2O2Se, as a novel two-dimensional (2D) material, is attracting much attention owing to unique electrical and optoelectrical properties. Particularly, 2D Bi2O2 Se with high mobility and a suitable bandgap has been predicted to be a promising thermoelectric material. Here, we performed systematic investigation of thermoelectric properties of 2D Bi 2O2Se through both experimental measurements and theoretical calculations. It is found that the post-growth 2D Bi2O2 Se nanoplates exhibit semi-metallic behavior because of existence of oxygen vacancies . Furthermore, vacancy engineering through annealing, which effectively tunes the concentration of oxygen vacancies, can significantly enhance the Seebeck coefficient of 2D Bi 2O2Se (30–90 μV/K) and the power factor (1–2.7 μW/cm/K2 ), competitive as an air-stable oxide thermoelectric material . Our results not only demonstrate the promising power factor of 2D Bi 2O2Se, but also provide a general and alternative strategy of vacancy engineering for tuning the thermoelectric properties of low-dimensional materials.

Water scarcity is one of the greatest challenges facing human society. Because of the abundant amount of water present in the atmosphere, there are significant efforts to harvest water from air. Particularly, solar-driven atmospheric water generators based on sequential adsorption-desorption processes are attracting much attention. However, incomplete daytime desorption is the limiting factor for final water production, as the rate of water desorption typically decreases very quickly with decreased water content in the sorbents. Hereby combining tailored interfacial solar absorbers with an ionic-liquid-based sorbent, an atmospheric water generator with a simultaneous adsorption-desorption process is generated. With enhanced desorption capability and stabilized water content in the sorbent, this interfacial solar-driven atmospheric water generator enables a high rate of water production (≈0.5 L m-2 h-1 ) and 2.8 L m-2 d-1 for the outdoor environment. It is expected that this interfacial solar-driven atmospheric water generator, based on the liquid sorbent with a simultaneous adsorption-desorption process opens up a promising pathway to effectively harvest water from air.

We are part of a growing community of researchers who are developing a new class of soft machines. By using mechanically soft materials (MPa Modulus) we can design systems which overcome the bulk-mechanical mismatches between soft biological systems and hard engineered components. To develop fully integrated soft machines—which include power, communications, and control sub-systems—the research community requires methods for interconnecting between soft and hard electronics.Sensors based upon eutectic gallium alloys in microfluidic channels can be used to measure normal and strain forces, but integrating these sensors into systems of heterogeneous Young’s Modulus is difficult due the complexity of finding a material which is electrically conductive, mechanically flexible, and stable over prolonged periods of time. Many existing gallium-based liquid alloy sensors are not mechanically or electrically robust, and have poor stability over time. We present the design and fabrication of a high-resolution pressure-sensor soft system that can transduce normal force into a digital output. In this soft system, which is built on a monolithic silicone substrate, a galinstan-based microfluidic pressure sensor is integrated with a flexible printed circuit board. We used conductive thread asinterconnect and found that this method alleviates problems arising due to the mechanical mismatch between conventional metal wires and soft or liquid materials.Conductive thread is low-cost, it is readily wetted by the liquid metal, it produces little bending moment into the microfluidic channel, and it can be connected directly onto the copper bond-pads of the flexible printed circuit board. We built a bridge-system to provide stable readings from the galinstan pressure sensor. This system gives linear measurement results between 500Pa-3500Pa of applied pressure.We anticipate that integrated systems of this type will find utility in soft-robotic systems as used for wearable technologies like virtual reality, or in soft-medical devices such as exoskeletal rehabilitation robots.