The US Department of Defense has awarded a team of nine professors from six universities $6 million over five years to exploit precise biological assembly for the study of quantum physics in nanoparticle arrays. The research will help to produce a fundamental understanding of quantum electronic systems, which could impact the way future electronics are created. Leading the effort is electrical and computer engineering professor Richard Kiehl of the University of Minnesota, who has wide experience in investigating the potential of novel fabrication techniques, physical structures and architectures for electronics. Kiehl has brought together a multidisciplinary team to develop biological strategies combining DNA, proteins and peptides with chemical synthesis techniques to construct arrays of nanoparticles and to systematically characterize the resulting quantum electronic systems. Quantum electronic systems are strongly influenced by interactions both within and between nanoparticles, and are extremely sensitive to the quality and dimensions of the structure. A nanoparticle array consists of metal particles with a diameter of 0.5 to 5 nm. The interactions among them produce highly correlated behaviors that could lead to exotic quantum physics, as well as to new mechanisms for computing, signal processing and sensing. But even basic studies of such nanoparticle arrays have been hampered by the need to fabricate test structures with extreme control and precision. Most semiconducting devices, such as computer chips, are made from the top down. Patterns are imposed on the material and etched into it. The biological assembly technique aims at building from the bottom up, atom by atom or molecule by molecule. "By exploiting biology to precisely control size, spacing and composition in the arrays, we will be able to examine electronic, magnetic and optical interactions at much smaller scales than before," said Kiehl. "Our project blends some really fascinating science at the edges of biology, chemistry, materials science and physics. And, I'm excited about the chance to impact how electronic circuits could be engineered in the future." The team members are UCLA professors Yu Huang (materials science), Kang Wang (electrical engineering) and Todd Yeates (biochemistry); New York University professors Andrew Kent (physics) and Nadrian Seeman (chemistry); University of Texas at Austin professor Allan MacDonald (physics); University of Pennsylvania professor Christopher Murray (chemistry and materials science); and Columbia University professor Colin Nuckolls (chemistry). Kiehl and Seeman have previously collaborated in the first demonstrations of metallic nanoparticle self-assembly by DNA scaffolding, which will be central to this project. Seeman will exploit DNA nanotechnology to construct 2-D and 3-D scaffolding, while Huang and Yeates will use peptides and proteins to make nanoparticle clusters for assembly onto the scaffolding. Murray and Nuckolls will synthesize metallic and magnetic nanoparticles with organic shells that will self-assemble onto the scaffolding and control the interparticle coupling. Kent, Kiehl and Wang will carry out experiments to characterize the electronic, magnetic and optical properties of the arrays. MacDonald will provide theoretical guidance for the studies and analysis of the experimental results. The award was announced this week as one of 36 funded under the DoD Multidisciplinary University Research Initiative (MURI) program. The 36 projects total $19.4 million in fiscal 2007 and $207 million over five years. For more information, visit: www.defenselink.mil/releases/release.aspx?releaseid=10585