title: Evolution of a designless nanoparticle network into reconfigurable Boolean logic.
abstract: Natural computers exploit the emergent properties and massive parallelism of interconnected networks of locally active components. Evolution has resulted in systems that compute quickly and that use energy efficiently, utilizing whatever physical properties are exploitable. Man-made computers, on the other hand, are based on circuits of functional units that follow given design rules. Hence, potentially exploitable physical processes, such as capacitive crosstalk, to solve a problem are left out. Until now, designless nanoscale networks of inanimate matter that exhibit robust computational functionality had not been realized. Here we artificially evolve the electrical properties of a disordered nanomaterials system (by optimizing the values of control voltages using a genetic algorithm) to perform computational tasks reconfigurably. We exploit the rich behaviour that emerges from interconnected metal nanoparticles, which act as strongly nonlinear single-electron transistors, and find that this nanoscale architecture can be configured in situ into any Boolean logic gate. This universal, reconfigurable gate would require about ten transistors in a conventional circuit. Our system meets the criteria for the physical realization of (cellular) neural networks: universality (arbitrary Boolean functions), compactness, robustness and evolvability, which implies scalability to perform more advanced tasks. Our evolutionary approach works around device-to-device variations and the accompanying uncertainties in performance. Moreover, it bears a great potential for more energy-efficient computation, and for solving problems that are very hard to tackle in conventional architectures.
authors.affiliation: NanoElectronics Group, MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, Enschede 7500 AE, The Netherlands.
authors.forename: S K
authors.identifier: http://orcid.org/0000-0001-8848-5097
authors.initials: SK
authors.lastname: Bose
authors.affiliation: NanoElectronics Group, MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, Enschede 7500 AE, The Netherlands.|Programmable NanoSystems and Formal Methods and Tools, MESA+ Institute for Nanotechnology and CTIT Institute for ICT research, University of Twente, PO Box 217, Enschede 7500 AE, The Netherlands.
authors.forename: C P
authors.identifier: http://orcid.org/0000-0002-5429-1320
authors.initials: CP
authors.lastname: Lawrence
authors.affiliation: NanoElectronics Group, MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, Enschede 7500 AE, The Netherlands.
authors.forename: Z
authors.initials: Z
authors.lastname: Liu
authors.affiliation: NanoElectronics Group, MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, Enschede 7500 AE, The Netherlands.
authors.forename: K S
authors.initials: KS
authors.lastname: Makarenko
authors.affiliation: Multiscale Modeling and Simulation, MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, Enschede 7500 AE, The Netherlands.
authors.forename: R M J
authors.initials: RM
authors.lastname: van Damme
authors.affiliation: Programmable NanoSystems and Formal Methods and Tools, MESA+ Institute for Nanotechnology and CTIT Institute for ICT research, University of Twente, PO Box 217, Enschede 7500 AE, The Netherlands.
authors.forename: H J
authors.initials: HJ
authors.lastname: Broersma
authors.affiliation: NanoElectronics Group, MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, Enschede 7500 AE, The Netherlands.
authors.forename: W G
authors.initials: WG
authors.lastname: van der Wiel