Recent progress in flexible sensors based on 2D materials

With the rapid development of the internet of things (IoT) and wearable electronics, the role of flexible sensors is becoming increasingly irreplaceable, due to their ability to process and convert information acquisition. Two-dimensional (2D) materials have been widely welcomed by researchers as sensitive layers, which broadens the range and application of flexible sensors due to the advantages of their large specific surface area, tunable energy bands, controllable thickness at the atomic level, stable mechanical properties, and excellent optoelectronic properties. This review focuses on five different types of 2D materials for monitoring pressure, humidity, sound, gas, and so on, to realize the recognition and conversion of human body and environmental signals. Meanwhile, the main problems and possible solutions of flexible sensors based on 2D materials as sensitive layers are summarized.