This report describes a novel method to produce fluffy and resilient nanotube aerogels by combining solution blow spinning and Atom Layer Deposition (ALD). Polyvinylpyrrolidone (PVP) sponges obtained by blow spinning are used as templates and are deposited in ALD. After removal of template, semitransparent aerogels whose density can be as low as 0.68 mg/cm 3 were obtained. The product is heat-stable, with the ability to retain original shape and keep elastic after being kept at 900°C for 2 hours. It is also heat-insulated, with a thermal conductivity of 0.022 W/K•m at room temperature. Additionally, when compressed to 60% of the original height for 100 cycles during in-situ mechanical test, the sponges recovered to around 80% of the original shape, further indicating excellent mechanically elasticity of the aerogel. K E Y W O R D S aerogel/aerosol, elastic materials/properties, nanotubes, thermal conductivity Chencheng Xu and Haolun Wang contributed equally to this work.

Ultrathin metal fibers can serve as highly conducting and flexible current and heat transport channels, which are essential for numerous applications ranging from flexible electronics to energy conversion. Although industrial production of metal fibers with diameters of down to 2 μm is feasible, continuous production of high-quality and low-cost nanoscale metal wires is still challenging. Herein, we report the continuous draw spinning of highly conductive silver submicron fibers with the minimum diameter of ∼200 nm and length of more than kilometers. We obtained individual AgNO/polymer fibers by continuous drawing from an aqueous solution at a speed of up to 8 m/s. With subsequent heat treatment, freestanding Ag submicron fibers with high mechanical flexibility and electric conductivity have been obtained. Woven mats of aligned Ag submicron fibers were used as transparent electrodes with high flexibility and high performance with sheet resistance of 7 Ω sq at a transparency of 96%. Continuous draw spinning opened new avenues for scalable, flexible, and ultralow-cost fabrication of extra-long conductive ultrathin metal fibers.