Studies on flexible strain sensor based on AgNWs-PDMS electrodes

With the development of our society, people need electronic devices more and more frequently. Stretchable sensors have been widely applied to biological fields due to their unique capacity to integrate with soft materials and curvilinear surfaces. Because of the increasing demand for flexible electronic equipment, people put forward higher requirement to electronic devices, especially in the health monitoring, human motion detection, human-machine interface soft robot and other personalized needs. Stretchable microelectrode is applied in various fields, such as wearable electronic skins for soft robotics and wearable electronics for biomedical patches, etc. It is still challenging to develop strain sensors that satisfy both high stretchability and high sensitivity. Traditional sensors rarely have the ability to distinguish directions on the basis of high flexibility, ultra-high stretchability and great transparency. This study describes a fabrication method of microsized silver nanowires (AgNWs) patterns based on poly dimethylsiloxane (PDMS) substrate by using lithography. Serpentine patterns of AgNWs conductive sheets were created on the wafer. We demonstrate an ultra-stretchable, highly sensitive and transparent resistance-type strain sensor based on a nanocomposite containing PDMS and AgNWs. We put our sensor to fingers, elbows and knees to detect the bent of the joint obviously. The proposed flexible strain sensor with the serpentine patterns of electrodes has the potential applications for various flexible electronic devices. The flexible strain sensor has the potential to be used in biological and wearable applications.