Trevor J. Thornton - US grants

9979403
Balanis

The antenna is one of the fundamental distinctions between a wired and a wireless system. The design of the antenna impacts the development of each component - from the circuit design to the receiver structure and coding technique, as well as the channel access protocol - employed in future wireless communication networks. The most challenging environment for the design of each component is where the communication devices are extremely small, low power computing and consuming mobile terminals. Furthermore, these terminals may be able to move randomly and organize themselves in an ad hoc communication structure. Such a network of communication terminals is referred to as a mobile ad hoc network (MANET). It is proposed to investigate the use of adaptive antennas (i.e., smart antennas) to improve channel quality in a MANET. The design of a smart antenna for a MANET will pose many challenges in antenna, feed network, signal processing, receiver, and protocol designs.

The antenna must be designed to be conformal to the portable device and to adapt to the needs of the MANET. Depending on the needs of the MANET, the antenna will be designed to have different modes of operation from omni-directional to highly directive. A single antenna element will not be able to achieve these characteristics and therefore, a collection of elements, referred to as an array, will be needed. The array is a versatile antenna system and can perform many different functions (including scanning, beam forming, etc.) by primarily controlling the excitation amplitude and phase of its elements. The feed network devices and circuitry, and the signal processing algorithms which must be developed and also integrated into the entire system, will provide the desired excitation of the elements for the antenna to meet the needs of the MANET. The challenges to achieve these objectives include selection of the antenna element and array geometry, and the modeling of the antenna system. The physical realization of the selected antenna configuration and the integration of the antenna and feed network models as well as the analysis of the effect of the antenna on the overall system performance will be investigated. In addition, the modeling of the propagation channel (multi-path, fading, etc.) will also have fundamental impacts on the overall antenna system design.

The antenna feed network, consisting of controlling and matching devices and circuits, will require extensive analysis and design tools. To accomplish the tasks presented in this proposal, a large number of circuits operating at future communication frequencies (20-GHz range), including matching networks, low-noise and power amplifiers, oscillators, phase shifters, and mixers must be developed. The circuits will be highly compacted and fabricated in several layers to fit within the relatively small area available in a communication device. This task requires clever selection of the semiconductor material for fabrication, optimized semiconductor device structures, appropriate high-frequency circuit designs, and highly accurate device and circuit analysis tools. Moreover, the signal processing algorithms used in driving these circuits must be considered in the overall design.

The signal processing algorithms, to control and adapt the different modes of operation of the antenna, will be developed for analog and digital antenna beam-forming at high (20 GHz) frequencies. This work will include the development of algorithms for computation of gains and phases for use in analog phase shifters for the antenna array. Although phase shifters will be initially realized in the analog domain, a DSP algorithm will compute the gain and phase. The challenge here lies in the frequent computation of antenna parameters intended for operation in a rapidly changing environment such as a MANET. Digital realizations will be addressed by developing spatio-temporal signal processing algorithms for beam-forming. Channel coding may als0 be employed to provide diversity and to suppress residual interference for multi-user communications over fading channels. By using channel coding techniques, the same error rates with a lower signal-to-noise ratio may be obtained resulting in an improved battery life of each mobile terminal.

From a networking point of view, smart antennas may improve the performance of current channel access techniques for MANETs and may allow for the development of new protocols. By employing an array of antennas, it may be possible to develop protocols to control the multiple access interference in the spatial dimension, as opposed to time or frequency, to further improve the performance delivered to the terminals operating in a MANET. The design of such channel access protocols is dependent on the signal processing technique used in the smart antenna system.
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This award from the Major Research Instrumentation program to Arizona State University will be used to acquire an inductively coupled plasma (ICP) etcher to support a broad spectrum of well-funded interdisciplinary research programs with a common focus on new integrated microsystems technologies for novel, high payoff applications. The unique performance of this equipment provides a critical tool that will substantially enhance wide bandgap semiconductor and silicon fabrication capabilities, and thereby open up new frontiers in microsystems concepts and applications for active exploration and discovery. The equipment is configured with two independent etch chambers and ICP sources to run a chlorine-based etch process for group III - nitrides, and a "Bosch" fluorine-based process for deep etching of silicon. The dual chamber system will avoid process cross-contamination and enhance overall reliability and robustness of the etching to be performed. Research supported by this equipment falls into one of two technology areas: (i) Wide Bandgap Materials, Devices and Microsystems, and (ii) Si-based Microelectromechanical Systems (MEMS). Researchers in interdisciplinary teams from Materials Engineering, Chemical Engineering, Electrical Engineering, Bioengineering, Mechanical Engineering, Physics, Plant Biology, Chemistry and Biochemistry will be the principal equipment users. It is anticipate that substantial breakthroughs in each of the target applications will be enabled through the new patterning capability of the ICP etch tool. The equipment will be run as a multi-user facility housed in the class M3.5 cleanroom of the interdisciplinary Center for Solid State Electronics Research (CSSER). Day-to-day operation of the equipment will be overseen by CSSER's Associate Director. The majority of the actual users of the equipment will be post-doctoral, graduate student and undergraduate student researchers. Students will benefit from hands-on training with state-of-the-art fabrication equipment and the exciting, creative environment of interdisciplinary microsystems research.

This award from the Major Research Instrumentation program will allow Arizona State University to create a state-of-the-art high density plasma processing facility that will provide unique micropatterning capabilities that cannot otherwise be realized. The new multi-user facility will bring catalyze research collaboration between materials scientists, chemical engineers, electrical engineers, physicists, chemists, and biologists, reflecting the highly interdisciplinary nature of the activities to be undertaken. Through this new capability and new synergies, ASU will contribute to the high technology industrial base by expanding research and education capabilities in the design, synthesis, fabrication, and application of novel microsystems. Research supported by this unique high tech processing equipment will enable advances in interdisciplinary advanced materials research in two high-payoff areas: (1) silicon-based nanostructure science and technology, and (2) wide bandgap semiconductor microsystems. Students and postdocs will benefit from hands-on training with state-of-the-art fabrication equipment and the exciting, creative environment of interdisciplinary microsystems research.

0097434
Thornton

The project outlined in this proposal aims to develop a new type of hybrid molecular-semiconductor chemical sensor that is highly integrated, cheap and versatile. The sensor consists of polarizable molecular monolayers that adhere (i.e. self-assemble) to an underlying CMOS-compatible integrated circuit. The molecular monolayers are designed in such a way that their physical structure changes after exposure to the chemical of interest. The change in physical structure leads to a change in their electrical polarization which is detected by a sensitive transistor immediately below the monolayer. It is possible to design the molecular monolayers to respond to a wide range of individual chemical agents. The device combines the enormous flexibility associated with organic synthesis with the mass production capability of silicon chips. If successful, the research the PIs are proposing will lead to chip-based sensors that are cheap enough to be considered disposable, yet contain multiple sensing elements. The sensing elements will be integrated at the nanoscale and each chip will be capable of detecting a wide range of chemical agents. It will be possible to integrate the sensing elements with peripheral electronic circuitry that will perform both analog and digital signal processing. The information provided by the chip can be fed to a central computer (e.g. a home or office p.c.) to form a complete system for monitoring chemicals that influence our quality of life.

The research will concentrate on the science and engineering that underpins a generic chemical sensing technology. Rather than focusing on a sensor that detects a single class of chemicals, they are looking to develop general principles that will allow them to build integrated sensors that can be tailored to a wide range of chemical classes. In this way a standardized processing technology can be used to build sensors for gas-phase or liquid-phase species that could be organic, biological or inorganic in nature. This vision is analogous to the way in which present day CMOS can be used to build analog or digital circuits for different applications including information processing, communications and power electronics. As a demonstrator of this technology the PIs propose to fabricate a chip-based sensor that combines circuitry for basic analog signal processing with molecular monolayers that are individually and selectively sensitive to different chemical agents. For demonstration purposes, they shall focus on three prototype devices for sensing pH, metal ions and biologically important enzymes. However, their principal objective is to complete the basic research that would underpin a generic sensing technology based on hybrid molecular-CMOS integrated circuits.

The PIs propose a highly comprehensive and multidisciplinary program to investigate the preparation and properties of chemically active organic molecules, the fundamental factors controlling the interfacing of these species with electronic materials, and the incorporation of the molecules into prototype devices for multi-use sensing applications. The work will combine molecular synthesis with novel device fabrication and advanced scanning probe imaging. The molecular synthesis will initially concentrate on specifically tailored porphyrin-based molecular monolayers that incorporate functional groups that will bind strongly to the surface of the underlying transistor. If this approach shows promise, other sensing molecules for other specific applications will be designed and synthesized.

The physical structure and orientation of the molecules on the semiconductor surface will be studied using a combination of scanning tunneling microscopy and atomic force microscopy. The visual, and quantitative data provided by the scanning probe images will be correlated with that provided by electrical measurements, to better understand the physical configuration of the molecular monolayers before and after exposure to the chemical agents of interest.

If successful this work will create a revolution in environmental sensing that will have widespread beneficial impact.

This grant provides support for the acquisition of alignment, bonding, and hot embossing tools for hybrid bioelectronic-nanofluidic systems. Combining the hard, solid, inorganic world of the silicon chip with the soft, wet, molecular world of biological systems will unlock an extraordinary potential for scientific advance and societal benefit. The acquisition of wafer alignment, bonding and hot embossing tools will allow a diverse group of scientists and engineers at Arizona State University to work together across traditional disciplines to better understand hybrid bioelectronic-nanofluidic systems and how they can be engineered for a variety of applications. ASU currently has a number of cross-disciplinary programs exploring the interface between electronic and biological/biochemical systems. Examples of the kind of structures coupling wet biology and chemistry to inorganic electronics include microfluidic channels patterned in glass or silicon substrates that are subsequently aligned and bonded to nano-transistor and/or nano-electrode arrays. Biomedical implants such as glucose sensors and neural electrodes already being developed at ASU will also benefit from advanced bonding capabilities, as will non-biological applications such as advanced packaging for micro-electro-mechanical systems and an expanded capability for the MEMS devices themselves.

These new tools will advance discovery while promoting training and learning in a number of ways including the NSF-funded Integrative Graduate Education Research and Traineeship (IGERT) program in Optical Biomolecular Devices. The entering group of IGERT students has been working on the design of a nano-robot system, based on moving microtubules on a patterned surface using biological molecular motors. The bonder/aligner tools we are proposing to acquire are ideally suited to the interdisciplinary learning, teaching and research philosophy that underpins the NSF IGERT program. Faculty will run Senior Design Projects through a cleanroom so that undergraduate students from a wide range of Departments gain exposure to these, and other, state-of-the-art processing tools. The bonder/aligner tools play a key role in the fabrication of prototype systems that will be used as demonstrators for any practical technology that emerges. The processing capability provided by this acquisition will be used in ASU outreach programs for teacher training (Arizona Mathematics-Science Technology Education Partnership AM-STEP). Materials produced by the aligner/bonding tools, including hands-on examples of integrated nano-bio-electronic systems, will be made available to teachers and their classrooms, and will be on display at the Arizona Science Center in downtown Phoenix. We shall work with an ASU co-director of the NSF sponsored Western Alliance to Expand Student Opportunities (WAESO) to further recruit talented under-represented minorities.

This proposal research is accommodation of a dual-beam focused ion beam (FIB) system for "milling" nanostructures is part of that initiative. Our broad goal is to develop a research competence and workforce trained in combining fabricated nanostructures with designer molecules. Examples of proposed molecule-based nanostructures are nanoscale electrode gaps for molecular electronics, nanofluidic enclosures for single molecule optics, probes for single-molecule electrochemistry, molecule-based sensor devices, nanoscale dielectrophoretic traps and sorters for nucleic acids and proteins, and nanostructured intelligent molecular coatings. Other applications of the FIB include prototyping novel device architectures, including molecule-based sensors, preparing materials for electron microscopy analysis, FIB tomography and other physical probes, and manufacture and characterization of
nanostructured materials.

Broader Impacts: The FIB will have a synergistic impact on major new programs at Arizona State University that integrate solid-state and molecular nanosciences. Through the IGERT it will serve to train a new breed of nanoscientist, spanning the chemistry-physics-engineering- biology spectrum. Training and outreach will utilize mechanisms put in place by INVSEE (Interactive Nano-Visualization for Science and Engineering Education (http://INVSEE.ASU.EDU). It will also be used in science teacher preparation programs (ACEPT and its successor AM-STEP). An on-line display at the Arizona Science Center will help to bring the concepts of nanoscience to the general public.

0932885
Posner

Over the past five years, there has been a growing interest in the health-related issue of toxicity of engineered nanomaterials. Cells have various routes for uptake of molecules and particles through their cell membranes to control their internal environment including highly selective membrane proteins and peptides as well as protein mediated endocytosis and phagocytosis. Nano-particle (NP) based drug delivery and molecular imaging applications that deliver NP into cells typically use biochemical functionalization which promote specific signaling and uptake. The lipid bilayers that make up cellular membranes are believed to be impenetrable to ions and unfunctionalized macromolecules, however, epidemiological studies have shown that unfunctionalized NPs can, under some conditions, cross or disrupt the cell membrane through passive, unmediated routes causing acute cellular toxicity and cell death. The unmediated NP adsorption onto and the uptake into cells is poorly understood. Recent research focuses on either collection of empirical epidemiological data (e.g. uptake of NP by cells, toxicity to organisms such as rats or fish) or precise NP characterization (e.g. size, shape, degree of aggregation, charge, and surface chemistry). However, it is almost impossible to transition from these measurements to detailed understanding of the mechanisms responsible for unmediated NP uptake into cells and disruption of the bilayer. Quantitative measures of nanomaterial bioavailability and toxicity need to be assessed so that the impact of nanotechnology on human health and the environment can be addressed.

Intellectual Merit: The intellectual merit of the proposed work is to understand the mechanisms and conditions under which engineered nanomaterials can cause disruption of, and passive transport through, simplified model cell membranes, namely lipid bilayers. The,investigators hypothesize that under some conditions engineered NPs can passively translocate across, and cause nanoscale defects in, bilayers which plays a role in cellular toxicity. The interaction of nanoparticles and lipid bilayers are unique because the particle and membranes have nearly the same length scale.

Broader impact: Fundamental understanding of the interaction between NP and lipid bilayers is potentially transformative because it may: (1) improve our understanding of toxicity of engineered and environmental NP; (2) enable rational design of benign NP for delivery of drugs and biomedical/molecular imaging; (3) result in high-throughput toxicity testing protocols; and (4) evidence-based regulation and protocols of nanomaterials. An experimental platform and methods will be developed for quantifying the NP transport through lipid membranes in real time as a function of the NP and lipid properties and the physicochemical environment. A "bottom-up" approach will be employed to increase the complexity of the bilayer through incorporation of membrane proteins as well as glycolipids to form an artificial glycocalyx.

Engineered nanoparticles are largely unregulated because the transport, fate, and toxicity of NP have not been adequately assessed. The proposed research focuses on the interactions of engineered nanomaterials with lipid bilayers, arguably the most important interface between life and the environment. This proposal addresses NP toxicity and has strong implications on the regulation of NP production, distribution, and application in medicine, clothing, cosmetics, etc. As an integral part of the proposed work, the PI aims to increase engineering and physical science graduate students' awareness of the societal and ethical implications of nano science and technology through: (1) development of a cross-listed graduate level course on the societal and ethical implications of nanotechnology; and (2) organization of a two week student workshop in Washington, DC which examines scientific policy and culture. The PI will also build upon his strong commitment to undergraduate research by funding underrepresented undergraduate researchers.

The National ATE Center for Nanotechnology Applications and Career Knowledge (NACK) is creating the "NACK Network", a designation that reflects the philosophy, structure, and operation to be developed across the U.S. The objectives are enhanced national coordination and dissemination of micro-nanofabrication workforce educational resources, programs, and activities, and enhanced growth of the US nanotechnology workforce. The methods to be employed include pressing forward the NACK approaches of (1) resource sharing among community colleges as well as among community colleges and research universities; (2) providing course materials that deliver a core set of industry-recommended nanotechnology skills; (3) stressing broad student preparation for careers in any industry utilizing micro- or nanotechnology; and (4) developing economically viable, quality nanotechnology education across the U.S. NACK Network methods also include further expansion of its alliance of community college/university and community college/community college resource-sharing hubs, including the addition of virtual hubs.

To support this network and all U.S. community college nanotechnology education efforts, the Network offers up-dated and free-of-charge core skills course lecture and lab materials, recruiting materials, retention and completion approaches, web-accessible equipment capability, and faculty development workshop curricula at its web site www.nano4me.org. In addition the NACK Network is developing and disseminating an assessment rubric for its core skill course lecture and lab materials, and continues to work with industry to have its core skills institutionalized into industry standards. The NACK Network continues to offer its well-received faculty development workshops and is further expanding its dissemination methodologies at www.nano4me.org with enhanced functionality and the further enhancement of social networking tools. Recruitment, retention, and education completion are key NACK Network-wide endeavors and include new tasks addressing these issues as they impact veterans, Hispanics, African-Americans, and women.

Intellectual Merit: The intellectual merit of NACK's activities lies in their addressing, researching, experimenting with, and evaluating effective-practice approaches for (1) motivating students from across the U.S. social and geographic spectrum to consider careers in nanotechnology; (2) enhancing student retention, completion, and future career opportunities; (3) defining and evolving a model nanotechnology workforce education program, and (4) helping to develop economically sustainable nanotechnology workforce programs in colleges. Based on positive feedback on the intellectual content of its products and services, the continuation has a clear vision of what the community values and needs.

Broader Impacts: The NACK Network materials, practices and services are having a broad impact across the US. Their ready-availability at www.nano4me.org is strengthening secondary and community college education, in particular, and STEM education, in general. NACK workshops bring faculty and administrators together from across the country and have resulted in a better national understanding of nanotechnology education demands and requirements, approaches, resources, and sustainability issues. In addition, NACK's partnering/resource-sharing approach is a model for all aspects of science and technology education. The NACK Network establishes a nation-wide experiential basis for effective, working, community college/community college and community college/research university resource sharing relationships.

In their totality, the intellectual merit and broad impact of the NACK Network activities are profoundly important to the nation's nanotechnology workforce, and to the global competitiveness of U.S. industry.

Arizona State University (ASU) will establish the Nanotechnology Collaborative Infrastructure Southwest (NCI-SW) as a NNCI site. The NCI-SW will support the advanced tool-set, faculty expertise and knowledgeable staff required by academic and industrial users performing research at the frontiers of nanoscience and engineering. Its training programs will focus on workforce development and entrepreneurial initiatives for 21st century manufacturing industries. A partnership between ASU, Maricopa County Community College District (MCCCD), and Science Foundation Arizona (SFAz) will allow two-year colleges in metropolitan Phoenix and rural Arizona to deliver a STEM-based nanotechnology curriculum designed to meet the economic development needs of their communities. Particular emphasis will be placed on programs in rural Arizona that support Hispanic and Native American students. Students in these programs will have access to advanced laboratory facilities either directly on the ASU campus or via remote access. Faculty and students from local high schools and community colleges will collaborate with ASU faculty on summer research programs at the frontiers of nanotechnology and develop lesson plans that convey the excitement of the latest discoveries back to their classrooms. Public outreach events at science fairs and at the Arizona Science Center will allow the wider community access to the latest breakthroughs in nanotechnology at ASU and from around the world.

The goals of the NCI-SW are to build a southwest regional infrastructure for nanotechnology discovery and innovation, to address societal needs through education and entrepreneurship, and to serve as a model site of the NNCI. The NCI-SW site will encompass six collaborative research facilities: the ASU NanoFab, the LeRoy Eyring Center for Solid State Science, the Flexible Electronics and Display Center (FEDC), the Peptide Array Core Facility, the Solar Power Laboratory (SPL), and the User Facility for the Social and Ethical Implications of Nanotechnology. The NCI-SW site will open the FEDC and SPL to the broader research community for the first time. The site will provide particular intellectual and infrastructural strengths in the life sciences, flexible electronics, renewable energy and the societal impact of nanotechnology. ASU will collaborate with Maricopa County Community College District (MCCCD) and Science Foundation Arizona (SFAz) to develop STEM materials with a nanotechnology focus for A.S. and A.A.S students in communities throughout metropolitan Phoenix and rural Arizona. NCI-SW will provide entrepreneurship training for users who wish to commercialize nanotechnology in order to benefit society. To facilitate the commercialization of research breakthroughs, the NCI-SW will support prototyping facilities and low-volume manufacturing pilot lines for solar cells, flexible electronics and biomolecular arrays. The Science Outside the Lab summer program at the ASU Washington DC campus will allow users across the NNCI to explore the policy issue associated with nanotechnology. A web portal hosted and maintained by MCCCD will provide seamless access to all the resources of the NCI-SW.

This Research Experiences for Undergraduates (REU) Site for Solar Energy and Photovoltaics Research is hosted by Arizona State University (ASU) using the facilities of the NSF/DOE jointly funded Quantum Energy and Sustainable Solar Technologies (QESST) Engineering Research Center (ERC). The challenge of sustainability meeting the world's energy demand-the "terawatt challenge"-has been described as the defining challenge of this generation. Many of the most pressing world issues today are fundamentally intertwined with energy, ranging from climate change to poverty. Photovoltaic (PV) devices are the most promising sustainable energy source, and have made the transition from lab to fab in the past decade. Provided that the PV industry maintains its present growth rates, it can provide all of the new electricity required by the world within a decade, and it can meet the world's total energy demand by 2050. However, motivated and innovative engineers in both academia and industry are needed to achieve this goal. The aim of the REU Site is for undergraduate students to be introduced to research generally and solar research specifically, to experience how the course work they are studying can be put into practice to tackle the terawatt challenge, and to practice how the principles of scientific research can be applied to any engineering challenge.

This REU Site offers opportunities for undergraduate students to engage in solar research during a 9-week summer program, on topics that range from fundamental (e.g., new growth methods for the active layers in III-V multi-junction solar cells) to applied (e.g., degradation mechanisms in silicon modules in the field). Participants in the REU program will be immersed in this intellectual melting pot of ongoing solar research, both strengthening existing projects (e.g., high-mobility transparent conductive oxides) and being involved in the initiation of others (e.g., silicon-based tandem solar cells). The REU projects will be designed to cross traditional disciplinary boundaries-as photovoltaic research is apt to do-synergistically combining device physics, materials science, chemistry, electrical engineering, and sustainability. The REU students' laboratory experience will be enhanced by seminars and workshops that provide them with access to experts in a wide range of fields including PV research and development, the social science of energy usage, sustainability, and the solar energy industry. The program will also include a number of social activities designed to encourage formal and informal communication skills, collaborative problem solving and teamwork with colleagues from diverse cultural, geographic, and demographic backgrounds. Each student will travel to one conference or workshop to present his or her work. The REU will recruit heavily from the network of QESST partner institutions, most of which have substantial populations of students that are under-represented in engineering. Through research that crosses disciplinary boundaries and a diverse base of mentors, this REU Site will retain students of all backgrounds in engineering as they pursue advanced degrees and careers.