Flame-retardant, highly sensitive strain sensors enabled by renewable phytic acid-doped biotemplate synthesis and spirally structure design

Highly sensitive strain sensors have considerable impacts on various applications. However, the utilization of noxious reagents, high cost, and flammability of the composites are vital obstacles to hinder the large-scale application of strain sensors. Here, an eco-friendly, flame-retardant and highly sensitive strain sensor is fabricated by renewable phytic acid-doped bio-template synthesis and spirally structure design. By this sustainable synthesis approach and unique structure design, our strain sensor exhibits high sensitivity (0.05% of strain detection limit) to distinguish the strains caused by liquid droplets with different densities and from different heights. The sustainable flexible sensors are further employed to monitor various human activities with good repeatability and reliability. Notably, the eco-friendly sensor is capable of self-extinguishing in 20 s after ignition, showing great flame retardancy. This study provides an eco-friendly and sustainable strategy of preparing highly sensitive flexible sensors based on renewable materials, which opens up new opportunities for the development of eco-friendly electronic devices.