In Situ Dynamic Manipulation of Graphene Strain Sensor with Drastically Sensing Performance Enhancement

It is extremely challenging to directly observe how the relative position of the nanosheet changes the charge transport in the channel. Previous work on graphene stacking strain sensors relies on nanosheet slip to detect small mechanical signals. However, the direct experimental verification evidence is still inadequate. In this work, the sliding conductive transmission of graphene nanosheets slip is directly measured through an improved in situ transmission electron microscopy observation technique. By accurately manipulating the atomic scale of graphene nanosheets to achieve nanoscale sliding, the resistance change between nanosheets in the in situ observation system can be directly measured. Besides, a mechanical sensor based on graphene layer structure is designed, which demonstrates a high gauge factor (4303 at maximum strain of 93.3%), negligible hysteresis (5–10%), and excellent stability over 3000 stretch–release cycles. Besides, the precise control of characteristics offers a practical approach of retaining high stability from device to device. This strain sensor is applied in various cases, especially the health monitor of the human cervical vertebra.