Reviewed by Lexie CornerJun 9 2025
Researchers at Wuhan Textile University, led by Professor Hualing He, developed an anisotropic thermoelectric aerogel inspired by the structure of human muscle. The study was published in Nano-Micro Letters.
As firefighting tasks grow more complex and hazardous, there is a growing need for protective gear that not only shields against extreme heat but also monitors temperature in real time.
The team created a composite called ACMCA, which is made from aramid nanofibers. It offers a combination of efficient energy conversion and strong thermal insulation. This makes it a promising material for self-powered, intelligent fire safety clothing.
ACMCA was formed using a directional freeze-drying process that produced a well-organized porous network resembling muscle tissue. This structure supports both electrical conductivity and directional heat transfer.
The resulting material is a flexible and lightweight aerogel, with a density of 0.038 g/cm³. It has a high Seebeck coefficient of 46.78 μV/K and low thermal conductivity of just 0.048 W/m·K.
These combined properties allow ACMCA to convert heat gradients directly into electrical signals. This function works without external power and supports real-time temperature monitoring.
In practical experiments, ACMCA showed a quick and consistent response to temperature changes. When integrated into firefighting clothing, it triggered a multistage high-temperature alarm system within 1.43 seconds of flame exposure. The system covered a wide temperature range, from 50 to 400 °C, allowing for early warning in extreme conditions.
Unlike traditional sensors that require batteries or external circuits, ACMCA operates without external power. This self-powered design simplifies system integration and enhances durability in harsh environments.
The muscle-inspired structure also provides directional heat transport and strong mechanical performance. ACMCA maintained its function after repeated bending, stretching, and compression. It retained over 85 % of its voltage output even after 300 cycles of deformation.
Its strength comes from a network formed by strong hydrogen bonding and van der Waals interactions. This network includes functionalized MXene, multi-walled carbon nanotubes (MWCNTs), and silver nanowires, creating a robust and conductive 3D structure. Additionally, the material forms a TiO₂-rich char layer during exposure to flame, which boosts thermal stability and improves fire resistance.
Beyond temperature sensing, the composite can be adapted for gas detection. When combined with CH₃NH₃PbI₃, the modified version (ACMCA-M) showed a noticeable color change and high selectivity for ammonia (NH₃). Ammonia is a toxic and explosive gas often present in industrial fires, making this feature valuable for safety applications.
ACMCA combines insulation, energy harvesting, real-time sensing, and mechanical durability in one material. Its scalable and environmentally friendly production process supports roll-to-roll manufacturing, making it suitable for use in firefighting gear, industrial safety equipment, and other high-temperature smart applications.
Journal Reference:
Yu, Z., et al. (2025). Muscle-Inspired Anisotropic Aramid Nanofibers Aerogel Exhibiting High-Efficiency Thermoelectric Conversion and Precise Temperature Monitoring for Firefighting Clothing. Nano-Micro Letters. doi.org/10.1007/s40820-025-01728-x.