An extreme condition-resistant superelastic silica nanofiber/MXene composite aerogel for synchronous sensing and thermal management.

With the rapid development of science and technology, it is urgent to develop the extreme condition-resistance and multifunctionality of sensors to broaden their application scenarios. Here, an extreme condition-resistant superelastic silica nanofiber (SNF)/MXene composite aerogel is fabricated by an ice-templating assembly strategy. The hierarchical three-dimensional cellular structure composed of conductive two-dimensional MXene nanosheets as a framework and flexible one-dimensional SNFs as a scaffold endows the composite aerogel with excellent mechanical and piezoresistive properties at an ultralow density of 9 mg cm⁻³. The assembled aerogel sensor shows a high sensitivity (−0.33 kPa⁻¹), ultralow detection limit (0.01 kPa), rapid response/recover time (72/99 ms), large workable strain range (1–80%), and good stability (>5000 cycles), capable of detecting various human motions in real time, whether faint pulse beating or strenuous running. More importantly, the composite aerogel still maintains excellent mechanical and piezoresistive stability (>1000 cycles) after high-temperature baking (600 °C) or at ultralow temperature (−130 °C), even in liquid nitrogen (−196 °C). Furthermore, the outstanding thermal insulation performance (24.7 mW m⁻¹ K⁻¹) and exceptional low-voltage driven Joule heating performance (126.5 °C at 5 V) of the composite aerogel are presented simultaneously in a dual-mode thermal management device integrating heat generation and insulation. Based on these characteristics, a multifunctional aerogel sensor that can be used for synchronous sensing and thermal management is demonstrated for the first time. This work offers a novel insight into the development of multifunctional aerogel sensors and greatly broadens the application scenarios of wearable devices. [ABSTRACT FROM AUTHOR]