Provided is an apparatus. In one embodiment, this apparatus includes a substrate having a surface, and a plurality of nanostructures each having a first end and a second end, wherein the first end of each of the plurality of nanostructures is attached to the surface. At least a portion of the second ends of the plurality of nanostructures, in this embodiment, are bent toward one another to form two or more similarly configured clumps each including two or more nanostructures.