Highly stretchable polymer/silver nanowires composite sensor for human health monitoring

Flexible strain sensors exhibit outstanding advantages in terms of sensitivity and stability by detecting changes in physical signals. It can be easily attached to human skin and clothed to achieve monitoring of human motion and health. However, general sensing materials shows low stretchability and cannot respond to signals under large deformation. In this work, a highly stretchable polymer composite was developed by adding small amount (0.17 wt.%) of silver nanowires (AgNWs) in stretchable conductive polymer materials. The conductivity of polymer/AgNWs composite is 1.3 S/m with the stretchability up to 500%. The stretchable strain sensor based on the polymer/AgNWs composite can respond to strain signals in real time, even for 1% strain response, and shows excellent stability over 1,000 loading/unloading cycles. Moreover, the strain sensor can be attached to human skin and clothed to monitor joints, throat and pulse of the human body. The human body electrocardiogram (ECG) signal was detected successfully with the polymer/AgNWs electrode, which is comparable to the signal obtained by the commercial electrode. Overall, the sensors enable monitoring of human movement and health. These advantages make it a potential application in wearable devices and electronic skin.