To the long list of exceptional physical properties of graphene, Stanford University engineers have added yet another: Piezoelectricity, the property of some materials to produce an electric charge when bent, squeezed, or twisted. The results were described recently in a paper published in ACS Nano.
Graphene is a wonder material. It is a hundred times better at conducting electricity than silicon. It is stronger than diamond. And, at just one atom thick, it is so thin as to be essentially a 2D material. Such promising physics have made graphene the most studied substance of the last decade, particularly in nanotechnology.
Yet, while graphene is many things, it is not piezoelectric.
Perhaps most valuably, piezoelectricity is reversible. When an electric field is applied, piezoelectric materials change shape, yielding a remarkable level of engineering control.
Piezoelectrics have found application in countless devices from watches, radios and ultrasound to the push-button starters on propane grills, but these uses all require relatively large, 3D quantities of piezoelectric materials.
The Stanford team’s engineered graphene has, for the first time, extended such fine physical control to the nanoscale.
