Engineers and scientists collaborating at Harvard University and the MITRE Corporation have developed and demonstrated the world's first programmable nanoprocessor. “This work represents a quantum jump forward in the complexity and function of circuits built from the bottom up, and thus demonstrates that this bottom-up paradigm, which is distinct from the way commercial circuits are built today, can yield nanoprocessors and other integrated systems of the future,” said Charles M. Lieber, who holds a joint appointment at Harvard's Department of Chemistry and Chemical Biology and School of Engineering and Applied Sciences. The work was enabled by advances in the design and synthesis of nanowire building blocks. These nanowire components now demonstrate the reproducibility needed to build functional electronic circuits, and also do so at a size and material complexity difficult to achieve by traditional top-down approaches. Moreover, the tiled architecture is fully scalable, allowing the assembly of much larger and ever more functional nanoprocessors. An additional feature of the advance is that the circuits in the nanoprocessor operate using very little power, even allowing for their miniscule size, because their component nanowires contain transistor switches that are ‘nonvolatile’. This means that unlike transistors in conventional microcomputer circuits, once the nanowire transistors are programmed, they do not require any additional expenditure of electrical power for maintaining memory. “Because of their very small size and very low power requirements, these new nanoprocessor circuits are building blocks that can control and enable an entirely new class of much smaller, lighter weight electronic sensors and consumer electronics,” said Shamik Das, the lead engineer in MITRE's Nanosystems Group.