The engineering of molecular products needs to be carried out by robotic devices, which have been termed nanorobots. A nanorobot architecture is used for biomedical applications in nanomedicine. A kekule structure in a molecular graph is nothing but a perfect matching in the graph. The minimum number of kekule structures that cover the edge set of a molecular graph G is known as the excessive index of G. The excessive index has been known to be a powerful tool for scheduling in the field of nanomedicine and simulation of nanoparticle structures. In this paper we determine the excessive index for armchair carbon nanotube, TUC4C8(S) nanotube and V -phenylenic nanotube. Copyright © 2014 American Scientific Publishers All rights reserved.