Stretchable MoS Electromechanical Sensors with Ultrahigh Sensitivity and Large Detection Range for Skin-on Monitoring.

Although two-dimensional (2D) layered molybdenum disulfide (MoS) has widespread electrical applications in catalysis, energy storage, display, and photodetection, very few reports are available to achieve MoS for electromechanical sensing. Here, we report a novel solution-processed MoS strain sensor by constructing nanojunctions between layered MoS nanosheets and high-conductivity silver nanofibers (AgNFs) inside an elastic film. Benefiting from the outstanding lubrication property of layered MoS nanosheets, these nanojunctions can be easily separated by strains, giving rise to excellent electromechanical response. The resulting MoS strain sensor for the first time exhibits ultrahigh sensitivity with a gauge factor of 3,300 in a large detection range over 10%. The pronounced strain-sensing ability, combined with fast response speed and good operational stability, enables the MoS sensor for real-time and skin-on monitorings of various physiological signals such as finger movements, pulse, and breath. Our results may pave the way to extend 2D materials in novel applications such as soft robotics and human-machine interfaces.