Soft heat pipes are vital in many applications. Inspired by the structure of a squid, we proposed a squid-like soft heat pipe with multiple heat transport branches that has excellent flexibility and outstanding thermal performance. Each branch could transport heat to different locations for multiple heating or cooling applications.The proposed soft heat pipe worked as a pulsating heat pipe with a unidirectional flow of liquid slugs and vapor bubbles. Its thermal performance was investigated at different heating temperatures, bending angles, and inclination angles. The result showed that the highest equivalent thermal conductivity of the squid-like soft heat pipe could be up to 6750 W/(m · K), almost 17 times that of copper. Besides, the bending angle had little effect on its thermal performance, with the equivalent thermal conductivity reducing 10%-13% when the heat pipe was bent from 0°to 90°. The thermal performance of the soft heat pipe was affected by the inclination angle, with the equivalent thermal conductivity reducing 20%-25% as the inclination angle was reduced from 90°to 30°. The proposed soft heat pipe is scalable by increasing the tube length and branches. It has many promising applications like waste heat recovery, electronic device cooling, personal thermal management, and renewable energy harvesting.

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Electrospinning offers remarkable versatility in producing superfine fibrous materials and is hence widely used in many applications such as tissue scaffolds, filters, electrolyte fuel cells, biosensors, battery electrodes, and separators. Nevertheless, it is a challenge to print pre-designed 2D/3D nanofibrous structures using electrospinning due to its inherent jet instability. Here, we report on a novel far-field jet writing technique for precisely controlling the polymer jet in nanofiber deposition, which was achieved through a combination of reducing the nozzle voltage, adjusting the electric field, and applying a set of passively focusing electrostatic lenses. By optimizing the applied voltage, the circular aperture of lenses, and the distance between the adjacent lenses, the best precision achieved using this technique was approximately 200 μm, similar to that of a conventional polymer-based 3D printer. This development makes it possible for printing 2D/3D nanofibrous structures by far-field jet writing for different applications with enhanced performance.

Back Cover: The cover image is based on the Research Article Squid‐like soft heat pipe for multiple heat transport by Kang et al. Soft heat pipes with high thermal performance are highly desired in many applications. Inspired by the squid structure, this paper developed a squid‐like soft heat pipe with excellent flexibility and outstanding thermal performance, which could heat or cool different locations simultaneously through the movement of liquid and vapor plugs induced by the evaporation and condensation of the working fluid.