Application of nanomaterials in flexible sensors

Flexible electronic sensors have widespread applications in both traditional and emerging fields, particularly for human-computer interaction (electronic skins, wearable electronic devices) and physical and environmental monitoring for people. Flexible electronic sensors can be bent and folded readily without interfering with their detecting performance. However, researchers still face many difficulties. For instance, traditional flexible materials (such as organic materials) are less sensitive to external signals, and the production progress of flexible sensors is complicated. This review recapitulates applications of nanomaterials in flexible electronic sensors. Firstly, the working principles and applications of three common types of flexible electronic sensors, the piezoresistive sensor, the capacitive sensor, and the piezoelectric sensor, are introduced. Then, the paper summarizes methods for improving sensors’ performance in health monitoring, disease diagnosis and biological detection by application of different nanomaterials to flexible substrates. Finally, the future development of flexible nanomaterial sensors prospects. It is found that nanocomposites of metal nanomaterials, carbon nanomaterials and other polymers with unique tuned photoelectrical properties show enhanced performance as flexible sensors and further research is needed to improve the material-substrate integration to promote the large-scale application as wearable sensors.