Biomimetic Carbon Tube Aerogel Enables Super-Elasticity and Thermal Insulation

Inspired by microstructures of polar bear hair, herein, we describe a simple solution-based strategy to fabricate a macroscopic-scale and lightweight carbon tube aerogel with super-elasticity and excellent thermal insulation. The microstructure-derived thermal conductivity and super-elasticity are strongly dependent on the shell thickness of the interconnected tubes, as well as the aperture of the aerogel. Remarkably, the optimized aerogel can maintain structural integrity after more than one million compress-release cycles at 30% strain and 10,000 cycles at 90% strain. Moreover, this biomimetic aerogel offers a fast and accurate dynamic piezoresistive response to broad bandwidth frequency forces. Particularly, the super-elasticity is further confirmed by its fastest rebounding speed of 1,434 mm s−1 among the traditional elastic materials measured by a standard falling steel ball. Furthermore, the optimized minimum thermal conductivity is as low as 23 mW m−1 K−1 which performs better than the thermal conductivity of dry air.