Caltech computer science professor Andre DeHon is changing the architecture of integrated circuits- and it needs changing. Conventional circuit elements are nearly as small as they can be, so materials scientists are fabricating nanowires 10 times smaller to replace them. DeHon described how to chemically modify the ends of nanowires so that the much larger wires used in conventional circuitry could address them individually. He then showed how to arrange such wires into working circuits, even within the limitations of existing lab techniques, and he has developed an architecture for building a general-purpose computer from them. Moreover, his processor can be reprogrammed to perform different computing tasks that would ordinarily require distinct architectures. This extends the work DeHon did as an MIT graduate student on reprogrammable semiconductor chips, a technology commercialized by several undergraduates he supervised, whose company, Silicon spice, was acquired by Broadcom for $1.2 billion. “Andre’s work is striking,” says Harvard University nanotech pioneer Charles Lieber. “After reading it one must say, ‘Yes, this idea of molecular computing is indeed a real possibility, not just hype.’”