The experimental procedure of nanostencil lithography and subsequent CVD to synthesize number- and location-controlled CNTs. (a) Evaporated iron catalyst is deposited through nanoapertures onto the substrate. The size of the deposited iron catalyst decreases with decreasing aperture size. (b) CNTs are synthesized on patterned catalyst, and the number of CNTs synthesized is controlled based on the size of catalyst pattern. Thus, number-controlled, location-specific synthesis of parallel-integrated CNTs can be achieved over a large area.