Electromechanical sensors

One application area for conductive nanosheets and their composites is in the fabrication of electromechanical sensors. These are materials whose electrical properties change in a well-defined way in response to deformation. For example, as they are stretched their resistance changes with strain, which allows them to be used as strain sensors. We have fabricated a number of types of electromechanical sensor from composites of graphene mixed with various polymers. Depending on the system, very large resistance changes can be obtained for very small applied strains. An example of this is the material G-putty which was demonstrated in our group recently. This material is a composite consisting of a mixture of graphene nanosheets and Silly Putty. The extremely soft nature of the Silly Putty results in an unusual composite where the graphene sheets are somewhat mobile. This results in extremely large resistance changes on deformation allowing the fabrication of extremely sensitive sensors.

smart putty physics

Electromechanical Sensors The G-putty sensing material (grey) compared to silly putty (red).