Graphene-Based Ultrasensitive Strain Sensors

We performed density function theory calculations to study the effect of strain on electronic properties of pristine and doped graphene. A dramatic change in density of states (DOS) and band structure is observed on doped graphene in the presence of uniaxial and biaxial strain. The analyses of density of states variations at the Fermi level and band gap in the presence of strain provide insight into the role of strain in affecting the conductivity of graphene. We demonstrated that band gap can be widely modulated in the presence of uniaxial and biaxial strains. It is found that the presence of dopants at low concentration can enhance the sensitivity of the sensor making it an ultrasensitive high-performance sensor which can sense strain up to ∼0.0001 at low doping concentration, which is almost impossible for currently used sensors, thus transforming graphene into an efficient strain sensing material. Due to its outstanding performance, the strain sensor can satisfy the need for subtle, complex, and large human motion monitoring that indicates its potential for its great applications in real-time motion monitoring, mechanical control, and health monitoring. These results can enhance our understanding of strain effects on electric properties of graphene and other two-dimensional (2D) materials....