David C. Jiles - US grants

This project is to study magnetic NDE methods for surfaces. The research will be conducted in conjunction with the Fraunhofer Institute at the Universitat des Saarlandes. A main component of the research will be the study of NDE magnetic effects related to the surface residual stresses such as are developed during shot peening.

This award is the result of the NSF initiative on QNDE of Large Structural Systems. The objective is to demonstrate the use of magnetic hysteresis and Barkhausen measurement technologies in establishing the safety of steel components in large railroad bridges from a practical viewpoint. In particular the growth of fatigue cracks will be emphasized.

9418363 Jiles This is a "TIE" project on the topic of "Assessment of Barkhausen Effect Measurement for Evaluation of Ground Steel Components," to be conducted by the Industry/University Cooperative Research Center for Grinding at the University of Connecticut and Iowa State University's Industry/University Cooperative Research Center for Non-Destructive Evaluation. The proposed activity is to conduct research to study and evaluate the grinding damage to components by using the magnetic Barkhausen effect measurements. The Center for Grinding Research at the University of Connecticut will be responsible for acquisition of specimens, X-ray characterization and surface grinding. The Center for Nondestructive Evaluation at Iowa State University will be responsible for performing the Barkhausen effect characterization of the material, computer analysis of the signals from the material, identification of relevant Barkhausen signal parameters for evaluation of grinding damages, and correlation of results with X-ray diffraction data. This project is being cost shared with the Industry/University Cooperative Research Center for Grinding at the University of Connecticut. The Program Director recommends Iowa State University be awarded $50,000 for 24 months to conduct a "TIE" project with the University of Connecticut.

9310273 Jiles The primary objective of this research is to make a quantitative examination of the relationships between microstructural parameters of a model metal material and global magnetic property changes. The metal is pure nickel, selected to avoid the complications of microstructural changes, such as hard second phases, that could complicate the analysis. Cathodic charging is employed to form hydrides at grain boundaries in the nickel and induce microcavities. Creep damage in nickel is assessed in terms of cavity number density and average size of cavities and compared to the bulk magnetic properties, coercivity and permeability. %%% This investigation could have technological impact in areas where high temperature creep damage is a potential problem, such as in steel components operating in power plants. ***

9532056 Jiles This award is to provide a better understanding of certain magnetic properties of steels that can be used for the nondestructive evaluation of its mechanical state. a theoretical model will also be developed to permit the phenomena to be used for safety predictions of steel structural members. Prior research has demonstrated the phenomena but its physical basis is poorly understood and how to use it under service conditions is therefore needed. The key idea is to use both surface and bulk measurements to assess the residual stress in these materials. Magnetic data has been shown to be highly sensitive to the mechanical condition of the material. ***

INT 9732135
Jiles


This U.S.-Czech research project between David Jiles of Iowa State University and partners, Ladislav Pust and Ivan Tomas of the Czech Institute of Physics, Prague, will examine the relationship between structure and properties of magnetic materials by developing computer based models of relevant magnetization processes. These efforts will feature energy dissipation as a result of magnetization where Bloch walls interact with regions that have different magnetic properties from the matrix. The researchers intend to emphasize pinning of magnetic domain walls on larger voids, non-magnetic inclusions, and regions of high localized stress.

This cooperative work will involve comparing theoretical model calculations with experimental data measured on iron and nickel based alloys. Results should provide a more complete theoretical framework for the description of magnetic properties of materials, i.e., hysteresis curve modeling, thereby improving our understanding of microstructural effects on magnetic properties. If successful, findings may be applied in magnetic nondestructive evaluation methods, an area of broad interest in materials research and engineering.

This project in theoretical materials research fulfills the program objective of advancing scientific knowledge by enabling experts in the United States and Central Europe to combine complementary talents and share research resources in areas of strong mutual interest and competence.

This award provides funding to Iowa State University, under the direction of Dr. David Jiles, for the support of a Combined Research-Curriculum Development project entitled, " Vertically Integrated Engineering Design for Combined Research and Curriculum Development." This project focuses on a combination of design experience and research to meet the educational needs of future generations of engineers in the most efficient manner possible and without increasing the number of course credits needed for graduation. The mechanism devised for achieving this is termed "vertically integrated design," which will provide a broader design experience for engineering students. This approach will engage students throughout their undergraduate career, beginning with sophomores, using state-of-the-art engineering simulators that illustrate the various critical stages in the life cycle of manufactured components. The specific field of research involved is nondestructive evaluation, which combines recent advances in life-cycle engineering, modeling and strong industrial interactions through the NSF Industry/University Cooperative Research Center for Nondestructive Evaluation. Formal courses on engineering practice and design will be taught in parallel with the experimental research project, which will involve sophomores, juniors and seniors working together.

This project lays the groundwork for a description of the Matteucci phenomenon. The research concentrates on one relatively simple class of materials known as permalloys in which magnetostriction can be controlled via the alloy composition. The project includes specimen preparation, structural characterization, and measurements of the changes in magnetic properties under torsional stress at different temperatures and magnetic field strengths. The work will develop a first principles, non-linear, hysteretic, theoretical model of the phenomenon. Nickel is the main material of choice for providing a reliable set of basic data; it has many advantages over other magnetic materials because of its relatively high magnetostriction, low anisotropy and high sensitivity to applied stress. In addition the magnetostriction coefficients along the <100> and <111> directions are comparable, resulting in a simpler dependence of magnetostriction on field. Nickel can be alloyed with iron to produce a series of materials with magnetostriction coefficients ranging from +7 ppm to -35 ppm, so that the dependence of the response on the magnetoelastic properties of the materials can be tested. All of these factors are an advantage in the search for a model to describe the observed behavior of the materials. This work will document the behavior of a relatively simple magnetic system under the action of torsional stress, will examine the magnetic response of these materials to torque under a variety of experimental conditions, and will develop model equations that help us to understand the performance of the material.
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The Matteucci effect, that is the change of magnetization of a material with torsional stress, is currently of great technological interest because of the search for materials for magnetic torque sensors. Magnetic properties of materials, particularly magnetization, are very sensitive to stress, and yet this behavior is poorly understood from a scientific viewpoint. This is because the Matteucci effect is non-linear and path dependent (hysteretic). At present there is no adequate theory that can be used to accurately describe this behavior.
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9910147
An exciting new possibility has arisen to investigate the enhancement of lifetimes of ferrous metals resulting from magnetic field treatment. The method seems feasible but is as yet scientifically unproven. The objective of this research is to evaluate the technology and to identify the nature of any beneficial effects on the performance of manufactured parts made from ferrous metals. We will also examine how this method works, optimize the conditions for its use and finally if it shows promise, determine how it may best be used.***

D.C.Jiles and J.E.Snyder


Progress beyond data storage densities of 100 Gbits/in2 requires a revolution in materials. Magnetic tunnel junctions provide a possible solution and are expected to form an essential component of future magnetic disk drive read heads, part of the $50 billion/year hard disk drive industry.

Tunnel junctions with a R/R of 30% have been announced in the last year. However there are serious problems with the current generation of tunnel junctions, which are based exclusively on an alumina barrier layer. These layers are now down to 0.7 nm in thickness and still the resistances of the tunnel junctions are too high for the intended applications. Essentially the alumina tunnel junction has reached its ultimate performance limits and there is a concern if alumina tunnel junctions will ever be able to be used in read heads and MRAM because of the high resistance. Therefore it is time for new tunnel junction materials to be brought forward based on alternative barrier layers.

Recently studies of alternative insulator materials by Fert et. al. showed that the barrier layer strongly affects the spin polarization in the magnetic layers. Freitas et al. have studied the effect of nitrogen additions to the alumina which changed the barrier height and resulted in an increase in tunnel magnetoresistance from 22% to 25% as the composition changed from Al2O3 to AlN.

However none of this has addressed the central problem of the overall resistance of the devices. In our proposed SGER we intend to make the radical change of completely replacing the alumina with other semiconductors. Of course this is a high risk endeavor, but the enormous benefits to the magnetic data storage industry that will accrue if the project is success make this a worthwhile exploratory investigation.

0138400
Jiles

Description: This award supports the US-India cooperative research entitled Magnetic Evaluation of Fatigue Damage and Deformation. Collaborators David Jiles, Iowa State University and Amitava Mitra, National Metallurgical Laboratory, Jamshedpur will conduct advanced Non-Destructive Evaluations (NDE) to obtain measurements on the structure of materials at the micrometer scale by using magnetic force microscopy and scanning Hall sensor microscopy. These will improve understanding of the relationships between microstructure and magnetic properties, which can then be used to interpret the results of traditional magnetic NDE measurements. The measurement data will be analyzed through mathematical modeling of the magnetization processes in materials using a new approach to the magnetic Preisach model. The research goal is to obtain specific details on how magnetic inspection methods can reliably be used to infer changes in structure and stress states during fatigue and deformation processes. This will greatly enhance the predictive capabilities of magnetic inspection techniques for estimating the remaining lifetime of components.

Scope: The idea that magnetic measurements could determine fatigue damage and deformation in materials has great potential and high relevance for the scientific community of engineers and materials scientists. For society, detection of impending failure in components could have significant impact for civil, aerospace, and mechanical structures. Jiles is the authority in the United States on using magnetic methods for NDE. The collaboration with the Indian scientists at National Metallurgical Laboratory will leverage the strengths of both laboratories. Under this grant, two US graduate students will have the opportunity to participate in the experimental work at the National Metallurgical Laboratory in Jamshedpur. This project is supported by the Indian Department of Science and Technology (DST) and by NSF's Office of International Science & Engineering and the Division of Civil and Mechanical Systems.

0437293
Jiles

This three-year U.S.-U.K. cooperative research project between the research group led by David Jiles at Iowa State University and A. J. Moses of the Wolfson Centre for Magnetics and Technology at the University of Cardiff addresses investigations in the magnetic and magneto elastic properties of a new class of magneto elastic composite materials. The proposal adds an international dimension to an existing NSF grant in materials research.

Intellectual Merit The investigators plan to conduct materials characterization measurements using state-of-the-art facilities at the Wolfson Centre. The investigators are focusing on hysteresis (loss of magnetism) - a problem common to composite magnetic materials. They will study the magneto mechanical properties in order to understand their function and to produce materials with the desired properties of low hysteresis loss and high stress sensitivity.

Broader Impacts In addition to the scientific research proposed here, the project also has a strong educational and training component. Through the international dimension, U.S. graduate students and a postdoctoral research will have an opportunity to learn about magnetic materials characterization methods being developed at the University of Cardiff using their state-of-the-art facilities. They will have developed research experience with an international team. There are plans to integrate the research results into an instructional course on magnetic materials and to involve undergraduate researchers through Iowa State's NSF-sponsored Research for Undergraduates Site.

This Focused Research Group award from the Division of Materials Research to Iowa State University is to characterize, understand, and improve upon a new class of magnetostrictive composite material discovered by Professor Jiles and collaborators, who were supported by a previous NSF-sponsored research (DMR-9902415). Primary thrust of the research would be to investigate both theoretical and experimental ways to enhance response linearity and to reduce hysteresis by exploiting an atomic substitution scheme at appropriate lattice sites in the material to reduce exchange-coupling leading to nonlinear hysteretic effects. The PIs will explore magnetoelastic composites based on cobalt ferrite in a metallic binder for use as stress sensitive materials in axial and torsional non-contact sensors. Alloys of cobalt ferrite with Silicon, Manganese and Cobalt (substituting these for the Iron in the ferrite) will be prepared to reduce the Curie temperature to room temperature thereby minimizing undesirable hysteresis. These new class of materials are expected to significantly improve magnetoelastic characteristics over competitive materials.
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This award could accomplish substantial research experience combined with promotion of teaching, training, and learning both at the graduate and undergraduate levels. The proposed collaboration with Moravian College, a leading undergraduate institution would be a broadening experience for both institutions and will likely create a synergistic relationship for years to come. A successful outcome of this award could be a significant technology transfer to a number of industries in the use of these stress sensitive materials in axial and torsional non-contact sensors in energy conservation and safety applications

Abstract:

The continuing evolution of sensor technology requires innovative approaches for reducing power consumption and improving sensitivity, resolution & operating temperature. The recent discovery of axion electromagnetic coupling in topological insulators holds great promise for drastic improvement of performance in sensor technology. This new class of materials has a bulk insulating energy gap and gapless Dirac-cone surface states which are protected by time-reversal symmetry. Unlike in traditional semiconductors, back-scattering is prohibited because of unique spin transport on the surfaces, leading to exciting non-dissipative applications. The striking electromagnetic coupling and half-integer quantum Hall effects open up completely new and revolutionary applications in nanoelectronics and spintronics. This project proposes to exploit the axion electromagnetic coupling effect in topological insulators and to build ultra-sensitive magnetic sensors that surpass the performance of traditional magnetometers.

Intellectual Merit: The intellectual merit of this project includes (i) the demonstration of the intriguing electromagnetic coupling effect in topological insulators that has not yet been experimentally explored; (ii) the improved understanding of material properties including magnetic doping of surfaces, and the growth of heterostructures involving magnetic oxides in which the surface gap is opened to invoke the coupling effect; (iii) the exploration of a novel quantum capacitance approach for the detection of surface states at high temperatures; and (iv) the invention of topological sensors operating at ambient temperature with unprecedented sensitivity and spatial resolution. The transformative concepts include the use of low-dissipation topologically protected surface-states of topological insulators for electronic and spintronic devices such as magnetic transducers, electrically tunable inductors, and quantum computation systems.

Broader Impacts: The proposed project will lead to a new magnetometer technology that exploits bulk properties and surface states of topological insulators. The high sensitivity, high spatial resolution and low-dissipation performance can satisfy the demanding requirements in sensor technology. The successful project is expected to have potential applications in medical research such as brain wave detection and in military surveillance with an enhanced magnetic sensitivity at low fields. The development of this project can potentially improve the competitiveness of the EPSCoR state #8722 (Iowa State) in the area of magnetic sensor devices. Besides the technological impacts, the program has a strong and comprehensive education component. Students will gain invaluable research experience in this highly interdisciplinary area of electrical engineering, physics, and materials science, leading to enhanced training and ability to pursue innovations for the entirety of their careers. The PI will create a multicultural environment by recruiting students from underrepresented groups, particularly female students, through the existing outreach programs "Science Bound" and "Program for Women in Science and Engineering" at Iowa State University. Full tuitions, research assistances and resources will be supplied for their education. The students can have ample opportunities to learn state-of-the-art sensor technology and gain hand-on experience on topological insulators. Such experience will broaden their scientific horizons and thus become invaluable assets to their future careers. The outcomes of the program will be incorporated into a course on sensor technology and disseminated in conferences & through peer-reviewed publications. The PI will also actively participate in the K-12 program at Iowa State and continue to offer mini-lectures on nanotechnology and magnetism. Research frontiers of the topological electromagnetic sensors can be included as interesting demonstrations, aiming to stimulating students' curiosity, creativity, and enthusiasm in science and technology.

Technical abstract
Cardiff University is one of the leading universities in the field of magnetics research in the UK and Europe. It is also home to several eminent faculty members in magnetics. Cardiff University and Iowa State Universities have had long-standing research collaborations and the PI and co-PI?s have all worked at Cardiff University and have good network connections with the current faculty and staff members. Cardiff University, and in particular the Wolfson Centre for Magnetics, offers resident expertise and access to advanced measurement facilities in magnetics. American students will gain good research experience from the work they will carry out at Cardiff University as well as the valuable broadening experience that comes from working in a foreign country.
The following five research topics match expertise and interests at both Iowa State University and Cardiff University and should attract a large number of applicants to the program: Magnetocaloric Materials; Magnetostrictive Materials; Non-Destructive Evaluation (NDE); Transcranial Magnetic Stimulation (TMS); Unified Theory of Hysteresis in Magnetic Systems.
Five students, two graduates and three undergraduates from colleges and universities across Iowa and who are permanent residents of the United States will be chosen for international research experience under this grant. Special efforts will be made to recruit under-represented minority or female students in STEM subjects. The students will spend ten weeks each summer at Cardiff University and two weeks at Iowa State University. The graduate students will be allowed to choose the research topics which will be closely related to their thesis. The undergraduates will be selected from Electrical & Computer Engineering, Materials Science & Engineering, Mechanical Engineering and/or Physics departments of Iowa State University and community colleges in Iowa. These undergraduate students will preferably participate in the summer months at the end of their junior year in order to enable them on their return to the United States, to take up senior design projects in similar areas if they wish.

Non-technical abstract
Iowa State University and Cardiff University in the United Kingdom will collaborate to offer 10 week research opportunities each summer for three years. The project will include 2 graduate students and 3 undergraduate students who will study at Cardiff University each year. The students, who will be permanent residents of the United States will be recruited from colleges and universities across Iowa. Special attention will be given to recruiting women and under-represented minority students in STEM subjects from colleges.

The Wolfson Centre at Cardiff University is one of Europe?s leading research institutes in magnetics. The topics chosen for the research are areas of common interest between Iowa State University and Cardiff University. These include: magnetocaloric materials, magnetostrictive materials, non-destructive evaluation, transcranial magnetic stimulation and computer modeling of hysteresis in materials.

This project will provide outstanding opportunities for students to gain research experience at a leading international research center in another country - the Wolfson Centre for Magnetics at Cardiff University, UK. These exciting, cutting edge projects will also motivate home grown undergraduate students to take up graduate studies, and graduate students to think about careers in research & academia.

PIs will promote the program by making visits to high schools in Iowa to help inspire the students to consider STEM subjects at university by demonstrating the various career options and opportunities for international travel in connection with participating in ground breaking research.

Proposal Title: On-chip studies of neuron cells under magnetic field stimulation

Brief description of project Goals:

This project is to develop a microchip for studying the single neuron cells and their interaction under magnetic field stimulation.


Nontechnical Abstract:
One in five Americans above the age of 18 suffer from diagnosable neurological disorders and there are 50,000 new cases of Parkinson's disease diagnosed every year in the United States. 10 to 20% of apparently healthy service members returning from conflicts in Iraq and Afghanistan suffer from post-traumatic stress disorder (PTSD). Therefore there is a critical need to develop new, safe, non-invasive methods for the treatment of deep brain disorders. Non-invasive techniques including repetitive transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) have had some success, but progress has been limited because of poor understanding of interaction of magnetic fields with neurons. Basically the molecular/cellular mechanisms of neurons under TMS are still lacking. To address these issues, the scientific and technical component of this project focuses on the investigation of the effect of transient magnetic fields on the neuronal growth rate and synaptic activity, which is essential in developing new treatment procedures for debilitating neurological disorders such as Parkinson's disease, PTSD and traumatic brain injury. The education, dissemination and outreach component of this project includes mentoring graduate, undergraduate and underrepresented/minority students, dissemination and outreach to the local community. The overall educational goal is to help next-generation workforce development by training students to carry out research with sound technical background and allowing them to gain hands-on laboratory skills for their advanced careers.

Technical Abstract:
The proposed project seeks to develop an integrated microchip that allows, for the first time, studying the growth, synaptic activity and regeneration of single neuron cells and interaction among the separated neuron cells under both AC/transcranial magnetic and DC magnetic field stimulation. Specifically, this project focuses on: (i) the development of a new microchip, which consists of microholder arrays with integrated patch-clamp probes to store single neuron cells; (ii) the study of the growth behavior and monitoring of the action potential of single neuron cells (N27 cells and PC12 cells as the models) under AC/transcranial magnetic field stimulation; (iii) the study of the growth behavior of the neuron cells inside a 3D extracellular matrix, mimicking the in vivo environment, under AC/transcranial magnetic field stimulation; and (iv) the study of the guided neuron growth by functionalizing the neuron cells with magnetic nanoparticles (mNPs) under DC and AC/transcranial magnetic field stimulation. This proposed research may help advance fundamental knowledge of growth and regeneration of single neuron cells under the magnetic field stimulation, which might have significant impact on the field of regenerative medicine from both scientific and engineering points of view. This proposed integrated technical platform offers some unique features otherwise unavailable by any other existing platforms, providing the capability for monitoring the behaviors of single neuron cells and the interactions among them. These functions in this platform might help trigger some basic discoveries, some important ideas and innovations for biomedical applications.

Electrical and computer engineering (ECE) technologies have evolved from simple electronics and computing devices and tools to complex systems that profoundly change the world we live in. Designing these complex systems requires not only technical knowledge and skills but also new ways of thinking and the development of social, professional and ethical responsibility. Through the RIDE project, the Department of Electrical and Computer Engineering at Iowa State University is involving students, faculty, engineers and others in collaborative, inquiry-driven processes to collectively and systematically transform the department and the engineers it trains. Students are not only learning about fundamental ECE technologies in core courses during their sophomore and junior years (middle years), but also the socio-technical context to go beyond the hardware and software toward responsible development. Students are expanding their analysis and design skills to create solutions that work for individuals and society. To accomplish these goals, faculty are reshaping core curricula using evidence-based pedagogical strategies and are working together to enhance their understanding and integration of these strategies in courses. This work is being done through new structures for collaboration and facilitated through departmental change processes. The project is expected to advance scholarly teaching and education research department-wide; serve as a model for ECE, computing and engineering departments across the country; enhance the capacity to conduct engineering education research at Iowa State; develop a diverse, socio-technical-minded ECE workforce; and broaden the participation of underrepresented groups in ECE, especially women, through inclusive learning experiences.

Through this project, the ECE department is undergoing a transformation to a more agile, less traditional organization able to respond to industry and society needs and sustain innovations. This transformation is being driven by the project's novel cross-functional, collaborative instructional model for course design and professional formation, called X-teams. X-teams are reshaping the core technical ECE curricula in the middle years through pedagogical approaches that (a) promote design thinking, systems thinking, professional skills such as leadership, and inclusion; (b) contextualize course concepts; and (c) stimulate creative, socio-technical-minded development of ECE technologies for future smart systems. X-teams are also serving as change agents for the rest of the department through communities of practice referred to as Y-circles. Y-circles, comprised of X-team members, faculty, staff, and undergraduate and graduate students in the department, are contributing to an organizational culture that fosters and sustains innovations in engineering education through an agile framework that blends several documented change theories, including collaborative transformation, crucial conversations, and essential tension. Y-circles are engaging in a process of discovery and inquiry to bridge the engineering education research-to-practice gap. Research studies are being conducted to answer questions to understand (1) how educators involved in X-teams use design thinking to create new pedagogical solutions; (2) how professional formation pedagogy in the middle years affects student professional ECE identity development as design thinkers; (3) how ECE students overcome barriers, make choices, and persist along their educational and career paths in the middle years; and (4) the effects of department structures, policies, and procedures on faculty attitudes, motivation and actions. These studies are informing and improving project activities, advancing knowledge, and supporting adaptation by others.

In the United States, about one in five Americans above the age of 18 suffer from diagnosable neurological disorders with no cure insight. As such, new, safe, non-invasive methods for the treatment of brain disorders are critically needed. Non-invasive techniques including repetitive transcranial magnetic stimulation (TMS) and transcranial direct current stimulation have had some success. However, progress has been limited due to poor understanding of the interactions of magnetic fields with nervous tissue. The molecular/cellular mechanisms of nervous tissue under TMS are still lacking. Hence, investigation of effects of transient magnetic fields on adult neurogenesis, cell differentiation and plasticity of nervous tissue (neurospheres) is essential in developing new treatment procedures and achieving the use of TMS as a neuromodulation tool for treating neurological disorders. The educational goal of this project is to effectively integrate research with educational activities and to train both undergraduate and graduate students in interdisciplinary studies to produce next-generation bioengineers. The PIs will develop a new Vertically Integrated Program (VIP) based on this research proposal entitled: Targeting Neurodegenerative Diseases Using Bioengineering Approaches. The VIP will unite undergraduate education and faculty research in a team-based context. The overall educational goal is to help next-generation workforce development by training students to carry out research with sound technical background and allowing them to gain hands-on laboratory skills for their advanced careers. The long-term goal is to design an automatic technical platform to synthesize a variety of in vitro central nervous system disease models to mimic in vivo conditions as closely as possible. This will facilitate the studies of TMS effects and drug screening assays for neurodegenerative disorders.

The goal of this proposal is to develop a chip-based microfluidics platform that facilitates the rapid formation of three-dimensional in vitro cell culture models of the central nervous system, which will permit the investigation of mechanisms of organ development, cellular interactions, disease model progression under magnetic field stimulation and drug treatments within de?ned microenvironments. Specifically, the proposed efforts include (1) the development of a chip consisting of microchamber arrays so that neurospheres including diseased neurospheres such as Alzheimer?s disease (AD) neurospheres can be fabricated in an efficient manner; and (2) the studies of the behavior of healthy neurospheres and AD neurospheres under transient magnetic stimulation (MS) and drug treatment using this chip. Major innovations of this proposed project can be summarized as the following: (1) Using this type of microfluidic chip, large-scale neurospheres with tunable and quantitative compositions can be synthesized rapidly and inexpensively, facilitating studies of different types of neurospheres; (2) Using a concentration gradient generator at the upper stream of this chip, a series of AD models (AD neurospheres) with known concentrations of amyloid-? and/or phosphorylated-tau can be readily fabricated; and (3) developing this chip will thus facilitate studies of the effects of both MS and drug treatment on AD models.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.