Large-Scale Nanofiber Manufacturing| A superelastic ceramic aerogel for flexiblepressure sensor in harsh environment

Flexible pressure sensors are widely used in human-machine interaction, health monitoring of human/equipment status, and other fields due to their low modulus, high sensitivity, and good adaptability.With the rapid development of smart firefighting, steel smelting, and new energy vehicle industries, higher requirements have been placed on the performance of flexible pressure sensors under extreme temperatures.However, currently reported flexible pressure sensors can only remain stable up to ~500°C, limiting their applications.Therefore, there is an urgent need to develop flexible pressure sensors that maintain high resilience, high sensitivity, and fast response/recovery over a wide temperature range to meet demanding application requirements.

Recently, Professor Dezhi Wu and Professor Yang Yang from Xiamen University published their latest research titled "A superelastic ceramic aerogel for flexible pressure sensor in harsh environment" in Composites Part B: Engineering.The researchers designed a capacitive flexible ceramic aerogel pressure sensor capable of stable operation across a wide temperature range from -196°C to 800°C.They constructed a ZrO₂-SiO₂ nanofiber aerogel (ZSNFAs) dielectric layer using Si-O-Si crosslinked oxide ceramic nanofibers as the framework, ensuring high stability and resilience under extreme temperatures.A highly stable flexible electrode with Ag-Pd-fiber interwoven structure was fabricated using direct ink writing (DIW) technology based on the Weissenberg effect, improving the sensor's conformal adaptability.Experimental results showed that the sensor maintained stable output over 1000 cycles at 800°C with a sensitivity of 0.262 kPa⁻¹.By integrating a sensor array into firefighting pressure-sensing gloves using deep learning technology, precise object recognition was achieved, which is significant for smart firefighting development.

A highly temperature-resistant, breathable, and conformally attachable ZrO₂-SiO₂ nanofiber membrane was used as the flexible electrode substrate, while high-viscosity conductive Ag-Pd paste served as the metal conductor to form a high-temperature-resistant flexible electrode (Fig. 1a).The flexible electrode with ZrO₂-SiO₂ nanofiber membrane as the protective layer was combined with a ZrO₂-SiO₂ nanofiber aerogel dielectric layer prepared by directional freeze-drying.

Through Ag-Pd paste bonding and pyrolysis processes, an extreme-temperature-resistant, thermally insulated flexible ceramic aerogel pressure sensor was constructed (Fig. 1c).Experimental results demonstrated that the sensor exhibited long-term stability over 1000 cycles at 800°C with a high sensitivity of 0.262 kPa⁻¹.At room temperature and liquid nitrogen environment (-196°C), the sensor maintained high and stable sensitivities of 0.259 kPa⁻¹ and 0.423 kPa⁻¹, respectively.Additionally, by integrating this sensor array into firefighting tactile gloves using deep learning technology, precise recognition of different objects was achieved.