Moletronics: future electronics

Over the past several years there have been dramatic advances toward the realization of electronic computers integrated on the molecular scale. First, individual molecules were demonstrated that serve as incomprehensibly tiny switches and wires one million times smaller than those on conventional silicon microchips1, 2, 3, 4. This has resulted very recently in the assembly and demonstration of tiny computer logic circuits built from such molecular-scale devices4, 5, 6, 7, 8, 9, 10. A major force responsible for these revolutionary developments has been the molecular electronics or ‘Moletronics’ Program organized by the US Government's Defense Advanced Research Projects Agency (DARPA). Previously, DARPA gave birth to the Internet in the 1970s and 1980s, revolutionizing the way the world communicates. Now, the agency is setting its sights on a new revolution in the nature, structure, and scale of the very materials with which the world both computes and builds. Ultimately, to compute with molecular-scale structures — i.e. nanometer-scale structures — one must learn how to characterize and organize them on similar scales, one by one and in vast arrays. This is creating a whole new science and industry of ‘nanostructured materials’, such as are portrayed in Fig. 1Download : Download high-res image (14KB)Download : Download full-size imageFig. 1. Moletronics nanostructured materials. (a) Electron micrograph of self-assembled ErSi2 nanowires developed at HP. (Reproduced with permission from54.); (b) electron micrograph of cowpea viral particle modified with gold nanoclusters developed at NRL to use as a template for molecular self-assembly; (c) simulation of Rice University's gold-nanoparticle electrical contacts on a surface in a ‘NanoCell’ molecular logic structure51; (d) structural diagram of NDR diode switch molecule20, 28, 35 and a simulation of its molecular orbitals involved in switching. (Reproduced with permision from47. Copyright 2000 American Chemical Society.); (e) gold nanobars synthesized at PSU; (f) electron micrograph of nanowire transistor-based logic circuit4 that was self-assembled and demonstrated at Harvard University.(Reprinted with permission from5. Copyright 2001 American Association for the Advancement of Science.). Fig. 1. Moletronics nanostructured materials. (a) Electron micrograph of self-assembled ErSi2 nanowires developed at HP. (Reproduced with permission from54.); (b) electron micrograph of cowpea viral particle modified with gold nanoclusters developed at NRL to use as a template for molecular self-assembly; (c) simulation of Rice University's gold-nanoparticle electrical contacts on a surface in a ‘NanoCell’ molecular logic structure51; (d) structural diagram of NDR diode switch molecule20, 28, 35 and a simulation of its molecular orbitals involved in switching. (Reproduced with permision from47. Copyright 2000 American Chemical Society.); (e) gold nanobars synthesized at PSU; (f) electron micrograph of nanowire transistor-based logic circuit4 that was self-assembled and demonstrated at Harvard University.(Reprinted with permission from5.