Lithography: rewriting the rules

 Dip-pen nanolithography (DPN) is generating significant interest as a means of patterning surfaces with submicron-scale designs. Advocates of DPN, which effectively uses an atomic force microscope (AFM) as a pen, herald its ability both to fabricate and monitor high-resolution, miniaturized molecular arrays. The novel technology is not without its critics, however, who question the utility and practicality of paint-pot-style nanofabrication. Nonetheless, the relative availability and affordability of DPN tools is allowing an increasing number of scientists and engineers to think small.In December 1959, the Nobel prize-winning physicist Richard Feynman gave a lecture to the American Physical Society that outlined his vision of a futuristic nanoscale world. He dismissed reports of fingernail-sized electric motors and devices that could cram text onto pinheads as little more than crude first steps towards true miniaturization. “It is a staggeringly small world that is below,” he advised the assembled throng.