Highly sensitive and flexible strain sensor based on AuNPs/CNTs’ synergic conductive network

Strain sensor is widely desired for flexible and wearable electronic devices, such as human motion capturing and electronic skin. In strain sensing, it is a challenge to ensure that the strain sensor based on CNTs–PDMS has both high-performance flexibility and sensitivity. Here, this study reports a flexible strain sensor based on the AuNPs/CNTs/PDMS composite films fabricated by in-situ reduction, which has high sensitivity and wide linear strain range. DFT revealed that the AuNPs effectively improved the conductivity of the composite films, which show high consistency with electrical test. The AuNPs synergistically improved the sensitivity and flexibility of strain sensors with CNTs in PDMS. The flexible strain sensors with 3 wt% CNTs and 16 h AuNPs’ reduction time have the higher gage factor of 366.7 at a linear strain ranging from 0 to 15%. We demonstrated the applicability of our high-performance strain sensors by testing the tiny motion sensing caused by wrist bending, finger bending, wrist raising, neck rotation, and facial muscle movement. The AuNPs/CNTs/PDMS composite film with high sensitivity, flexible, and stability provides a new elastomer nanocomposite as strain sensor for strain-sensing applications.