Top seven NNI nanosystems projects

Foresight Senior Associate Tihamer Toth-Fejel, a research engineer at General Dynamics, reports that he was able to locate 43 "nanosystems" studies in the list of NNI funded projects, some of which he reports look "somewhat promising" for molecular manufacturing. Read more to see his choice of the top seven projects funded. I found 43 on the www.nfs.gov website: http://www.nsf.gov/awardsearch/piSearch.do;jsessionid=7EAE526616AE930146D162304B0F403D?SearchType=piSearch&page=1&QueryText=nanosystem&PIFirstName=&PILastName=&PIInstitution=&PIState=&PIZip=&PICountry=&RestrictActive=on&Search=Search#results

Some *do* look somewhat promising, especially in terms of being able to use their results for real nanosystems.

The best seven are:

SGER: Shape-Dependent, Selective Self-Assembly for Nanomanufacturing
Carol Livermore-Clifford [email protected] (Principal Investigator)

This project will provide an initial demonstration and characterization of techniques to manufacture complex systems of nanocomponents rapidly, effectively, and inexpensively to meet a wide array of future nanomanufacturing needs. The proposed technique uses geometrically-selective self-assembly from fluid to organize nanoscalecomponents precisely into arbitrary, pre-determined, non-periodic systems. The technology will enable the creation of integrated nanosystems from separately fabricated functional nanocomponents in the 10 nm to greater than 1 mm size range. The substrate is patterned so that its topography at a given location is the exact inverse of theshape of the desired component at that location. Both substrate and components are chemically functionalized with a blanket coating of a hydrophobic self-assembled monolayer (SAM) to promote component-substrate attachment. The components and substrate are immersed in an appropriate fluid; components then contact the substrate randomly and stick. Because component-substrate binding energy scales with contact area, components attach much more strongly in shape-matched holes than on non-shape-matched surfaces. Megasonic excitation selectively dislodges the incorrectly-placed, more weakly-bound components while retaining the correctly placed, more strongly-bound components. Random contact and selective removal occur simultaneously, and the assembled configuration approaches the desiredconfiguration.The benefits of this approach include high positioning precision, simultaneous and selective assembly of diverse nanostructures, and a means of avoiding layer-to-layer alignment steps. The project has three primary goals. First is to characterize assembly yield and defect density vs. assembly time, megasonic excitation strength, hydrophobicity, and quality of particle/hole match using 1 mm-scale particles. Second is to demonstrate repeatable self-assembly into lithographically-defined shape-matched binding sites. Third is to relate the measured assembly yields to differences in binding energy in order to identify limits on selectivity and component size.

NIRT: Laser-Guided Assembly of Nanosystems
Gregory Timp [email protected](Principal Investigator)

The promise of nanotechnology won't be realized unless nanometer-scale structures can be assembled together inexpensively into a working system. The goal of this proposal is to develop and test a revolutionary tool that uses light-pressure forces to rapidly assemble complex nanosystems comprised of structures ranging in size from ~10nm to 1mm.Intellectual Merit: We plan to develop a tool to assemble a nanosystemlayer-by-layer using light pressure forces to produce multiple, independent optical traps for organizing simultaneously tens of thousands of nanometer-scale structures within each layer. The opticaltraps will be produced either by rapidly scanning a laser beam from one trap location to the next, relying on the viscosity of the medium to stabilize the position until the trap is refreshed, or by generating a hologram, where multiple optical traps are created simultaneously by controlling the intensity and phase profile of the beam using a spatial light modulator. Either way, the tool will have to compensate in real-time for the scattering environment of the trap during the layer-by-layer assembly. Therefore, there are two elements at the core of this proposal: 1. the efficient simulation of the dynamic electromagnetic environment of the trap, which is used to predict in real-time the required intensity and phase profiles for thelaser; and 2. the concomitant synthesis through adaptive optics of thetrap

NER: Device and Circuit Modeling of Integrated Nanoelectromechanical Systems (NEMS)
N Aluru [email protected] (Principal Investigator)

The objective of this research is to develop device modeling tools for NEMS, to extract compact models and to develop multi-phenomena based circuit simulation tools that can model NEMS along with other components of integrated nanosystems. The device modeling research will focus on self-consistent analysis of three mixed-energy domains -namely, electrostatics, mechanical and van der Waals energy domains.Hierarchical physical theories for electrostatics will be combined with van der Waals interactions and nanometer scale mechanical theories. The final goal of the device modeling effort is to extract parameterized reduced-order or compact models that can be used as input models for circuit simulation of integrated nano electromechanical systems. The circuit modeling research will focus onthe enhancement of the SPICE-based simulation framework with the capability to support multi-physics and multi-phenomena for CAD-based conceptualization, design exploration and synthesis of nanosystems. Specifically, the circuit modeling effort will focus on the circuit representation of the non-electrical components of NEMS as well as on the development of efficient time- and frequency-dependent simulationof NEMS.

NER: Computational Design of Bio-Opto-Electronic Nanosystems
Todd Martinez [email protected] (Principal Investigator)

This proposalis the "next step" in the development of computational tools for the simulation and design of photoactive protein devices. The complexity of photoactive protein complexes necessitates that simulation tools bedeveloped in such an incremental manner, and the steps to be undertaken with the proposed research are reasonable. Dynamical expansion, or "spawning", of the basis set is a key component of attempts to perform electronic structure calculations in regions of potential energy surfaces where Born-Oppenheimer breakdown occurs.Specifically, they will compute the effects of subtle changes, such asthe insertion of a charge, or steric crowding around the key functional group, in the vicinity of a chromophore of three prototypeproteins:GFP, PYP, bR. The goal is to be able to predict, and therefore control, the lifetime of the excited state by changing the structure and energy of the excited state relative to the ground state using these "mutational" changes.

Integrated Sensing: Collaborative Research: Development of Multifunctional Wireless Sensory Microsystems with Integrated Nanoelectromechanical Devices
Sanjay Raman [email protected] (Principal Investigator)

Recent advances in nanometer scale science and technology offer novel approaches for the development of ultra-miniature low-power sensor nodes for distributed wireless sensornetworks in applications such as environmental monitoring, civil infrastructure monitoring, condition-based maintenance, security and surveillance. The reduced dimensions and masses of nanoelectromechanical systems (NEMS) are of great interest for highly-sensitive force- and mass-sensing. We propose a novel technology based on assembly of nanostructured nanomechanical sensors rather than their direct machining from the substrate material.Nanomechanical sensing structures will be produced using "bottom-up"synthesis, then surface assembled and integrated with foundry-fabricated monolithic circuits through electrofluidic assembly, allowing on-chip integration of nanomechanical sensors with transduction, readout, processing, and communications circuitry. This approach also offers flexibility and scalability, enabling the assembly of a larger range of functional structures. Leveraging our core competencies in NEMS device development and analog/RF/microwave IC design, we will develop a micropower nanosensor-based microsystem containing nanosensor assembly/integration sites, sensor-specific transduction, and read-out electronics.

NIRT: Nanorobotics
Aristides A. Requicha [email protected] (Principal Investigator)

This research project is funded in response to the Nanoscale Science and Engineering Initiative, NSF 01-157, category NIRT. Nanorobotics isconcerned with (1) manipulation of nanoscale objects by using micro ormacro devices, and (2) construction, control and programming of robotswith overall dimensions at the nanoscale (or with microscopic dimensions but nanoscopic components). This project covers both of these aspects, because both are important: nanomanipulation is the most effective process developed until now for prototyping of nanosystems, and nanorobots with dimensions comparable to those of biological cells are expected to have revolutionary applications in environmental monitoring and health care-for example, in the early detection and destruction of pathogens. The initial research will be biased towards manipulation, with a focus on the automation of techniques developed in previous NSF grants for reliable and accurate nanomanipulation by using the tip of a Scanning Probe Microscope (SPM)as a sensory robot. Work on nanorobot construction will begin at a lowlevel but increase as the project evolves. It will integrate research on sensors, actuators, control, power, communications, and interfacingacross spatial scales and between organic/inorganic as well as biotic/abiotic systems. The theoretical and experimental results of this work will contribute to the understanding of robotics in domains with large spatial uncertainties, and to the development of NEMS (Nanoelectromechanical Systems). The software will be widely distributed and will be very useful to scientists and engineersworking in nanomanipulation and nanolithography.

Artificial Molecular Machines and Devices
J Fraser Stoddart [email protected] (Principal Investigator)

Under the influence oflight, electricity, or chemical reagents, certain interlocked molecules, known as catenanes and rotaxanes-which comprise appropriately matched ring and dumbbell-shaped components-will performmotions (e.g., rotary and linear) at a molecular level reminiscent of the moving parts of macroscopic machines. Such molecular motors hold promise as the intelligent" building blocks for the construction of devices and machines. A team of chemists and engineers from two different institutions (UCLA and nearby CALTECH) will address the fundamental scientific issues surrounding the relationships between controllable molecular machines, nanoscate devices, and the predictable movements of machine components at a macroscopic level. The aims of this collaborative project-which focuses on the NSE RESEARCH THEME of Nanoscale Devices and System Architecture-are to (I)develop the template-directed synthesis (self-assembly) of interlockedmolecules (switchable catenanes and rotaxanes) and interpenetrating supermolecules (addressable pseudorotaxanes) as a forerunner to (2) attaching them covalently to frameworks (e.g., silica, alumina) whose (3) synthesis(self-organization) must be established prior to (4) demonstrating theabilities of these machine-like (super)molecules to express different kinds of coherent movements (mainly linear but also possibly rotaryones) characteristic of macroscopic machines when (5) they are activated by chemicals (acids/bases or oxidizing/reducing agents) or electrons or light (redox and electron transfer processes) as a prelude to (6) transducing and amplifying the coherent molecular levelmovements into macroscopic motions. The specific objectives of the team are to demonstrate transduction of force and motion from the relative mechanical movements of the components present in catenanes, rotaxanes and pseudorotaxanes through the development-on the nanoscalelevel-of actuating materials and devices reminiscent of (1) engines, (2) levers,(3) muscles, and (4) valves. In thc first instance, we envisage constructing supramolecular two-stroke engines based on two-station pseudorotaxanes with the ring component lodged covalently in appropriately-sized silica pores, leaving the semi-dumbbell-shaped component to act as the piston. In the second example, we propose to design mechanical levers to amplify nanometer motions generated by suitable molecular or supramolecular machines. In the third instance, we propose to graft the ring and thread components of pseudorotaxanes onto separate carbon nanotubes using an aromatic polymer which we havedemonstrated wraps itself helically around carbon nanotubes in order to realize artificial muscles and actuators. And, in the final example, we intend to develop molecular valves at the necks of suitably-sized silica pores, lined with pseudorotaxanes that can be induced to associate and dissociate (rings from threads) such that guest molecules located within the pores are, respectively, trapped orfree to escape. The anticipated outcome of the proposed program of research includes (I) the synthesis of new molecular motors capable ofoperating as machines, (2) the synthesis of integrated power supplies for the machines, (3) a bottom-up and top-down integration of frameworks for the machines, (4) new fundamental understanding of forces, friction, etc., on the nanoscale, and (5) a group of students with both broad perspectives and individual expertise in nanoscicnce. With chemists and engineers working side-by-side, this highly integrated project seeks to transform molecular machines from being scientific curiosities into functioning nanosystems with technologicalpotential…

And finally, here are some people would definitely benefit from being turned to the dark side, away from quantum dots and into truenanosystems:

ITR/AP(DMR): Billion-Atom Multiscale Simulations of Nanosystems on a Grid
Priya Vashishta [email protected] (Principal Investigator)

This award is the result of a proposal submitted to the Information Technology Research initiative. The goal of the research is to developa scalable software infrastructure for large multiscale simulations ona Grid of geographically distributed, massively parallel supercomputers, as well as on future Petaflop computers. The multiscale simulation approach will combine, in a single Grid software, finite element (FE) calculation, the coarse-grained molecular dynamics (CGMD), molecular dynamics (MD) simulation, and quantum mechanical (QM) calculation based on the density functional theory (DFT). Continuum mechanics calculation based on the FE method will be performed with constitutive relations derived from the CGMD method in conjunction with MD simulations, which in turn will embed QMalgorithm described by the DFT. The following will be developed: (1) Grid-based FE/CGMD/MD/QM algorithms based on space-time multiresolution algorithms implemented with hierarchical decompositionon parallel/distributed computers for scalability and constrained-dynamics-based hybridization for seamless coupling of the hybrid simulation componets; (2) Space-time partitioned multiscale simulation combined with kinetic Monte Carlo (KMC) and parallel replica methods to couple disparate length and time scales; (3) Grid-computation tools including adaptive load balancing using wavelet-based computational-space decomposition and space-filling-curve-based adaptive data compression to reduce communication and storage; (4) Immersive and interactive visualizationof the large simulation data using octree-based visibility culling andparallel/distributed preprocessing of the visualization data with machine-learning predictive prefetch. The Gridified software will be used to study nanosystems of great importance to future information processing. Multiscale simulations involving 1,000- 10,000 QM atoms and 100 million – 1 billion MD atoms will be performed to study atomistically-induced phenomena, with emphasis on environmental effects where chemical processes play an important role.The multiscale algorithm will relate the atomistic processes to experimentally observable quantities, by covering an order-of-magnitude larger length scale (10 micron) through continuum mechanics and extending time scales through the KMC and replica methods. The simulations will focus on stress domains and their phononimaging in Si/Si3N4 and GaAs/Si3N4 nanopixels for sub-0.1 micron microelectronics applications and oxidation effects on them, and on substrate-encoded self-organized growth of lattice-mismatchedsemiconductor quantum dots (GaAs/InAs).

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