Prediction of giant electroactuation for papyruslike carbon nanoscroll structures: First-principles calculations

We study by first-principles calculations the electromechanical response of carbon nanoscroll structures. We show that although they present a very similar behavior to carbon nanotubes in their axial deformation sensitivity, they exhibit a radial response upon charge injection which is up to one order of magnitude larger. In association with their high stability, this behavior makes them a natural choice for a new class of very efficient nanoactuators.

Figure 1

Carbon nanotubes and scrolls can be topologically considered as cylindrical and papyruslike structures, respectively, obtained from rolled-up graphene layers.

Figure 2

(Color online) Unit cells used in the calculations of (a) an armchair and (b) a zigzag CNS. We have followed the nomenclature introduced by Braga et al. (Ref. 15), in turn derived from previous work on carbon nanoribbons (Refs 27, 28).

Figure 3

(Color online) Relative variation of the unit cell lattice parameter $l$ upon charge injection with respect to its equilibrium value in the neutral state $l_0$.

Figure 4

(Color online) Relative variation of the CNS diameter parameter $D$ upon charge injection with respect to its equilibrium value in the neutral state $D_0$. The diameter $D$ has been defined as the maximum distance between two carbon atoms with the same axial coordinate.

Figure 5

(Color online) Electronic density of states (DOS) of the armchair [red (gray) line] and the zigzag (black line) CNSs studied. The inset panel shows a magnified view around the Fermi level.

Figure 6

(Color online) Distribution of the extra charge of $-0.055\mid e\mid$/atom in a zigzag CNS.