1. A memristor comprising: a first electrode having a first surface; a cluster of electrically conductive nanostructures, wherein the cluster of electrically conductive nanostructures is provided in contact with the first surface, and wherein the cluster of electrically conductive nanostructure is relatively smaller than a width of the first electrode, wherein the electrically conductive nanostructures comprise a plurality of nano-particles that are stacked on top of each other; a switching material positioned upon said first surface, wherein the switching material covers the cluster of electrically conductive nanostructures; and a second electrode positioned upon said switching material substantially in line with the cluster of electrically conductive nanostructures, wherein an active region in the switching material is formed substantially between the cluster of electrically conductive nanostructures and the second electrode.