Nano Technologies

Magnetic Thick Films for Integrated Microwave Devices

This project is under DARPA's Magnetic Miniaturized and Monolithically Integrated Components (M3IC) program in the DARPA Microsystems Technology Office.

The objective of this effort is to develop thick-film magnetic materials that can be fabricated on semiconductor integrated circuits to enable highly miniaturized microwave components such as circulators and isolators operating in the 10 to 110 GHz frequency regime. These nonlinear, non-reciprocal components are critical for next generation radios, radar, and sensing systems for defense, consumer, automotive, and healthcare applications.

Zero-Power Magnetic Field Sensors Using Magnetoelectric Nanowires

We seek to develop a platform that allows magnetic field sensing using a small footprint, in the absence of an external power supply. Our approach uses magnetoelectric nanofibers to create a zero-power magnetic field sensor. The challenge is to develop methods to assemble these materials into devices that leverage their unique anisotropic properties.

The figure of merit for magnetoelectric materials is the magnetoelectric coefficient, a measure of the amount of voltage generated with respect to the magnitude of the applied magnetic field. Bulk magnetoelectrics and thin films are limited by defects and substrate clamping respectively.  To overcome the limitations of thin-film based composite magnetoelectrics we have developed magnetoelectric bilayer structures on a single nanofiber, i.e., 1D magnetoelectrics. These materials are theoretically predicted to have magnetoelectric coupling coefficients that are orders of magnitude greater than their thin film counterparts. 

Magnetoelectric materials can be employed in a wide variety of applications including magnetic field sensors and tunable resonance energy harvesters.  By optimizing for material system and architecture, drastic increases in magnitude of voltage generated with decreased size can be achieved. This could allow for more sensitive magnetic field sensors appropriate for a wider array of applications and decreased size to allow for easier integration into ICs.
 

Large-area Manufacturing of Integrated Devices with Nanocomposite Magnetic Cores

As predicted by Moore's "law", the past few decades have seen massive reductions in the size of integrated circuits, enabling the portable, handheld devices now in everyday use. However, the components that power these devices have not experienced a similar size reduction. For example, the power adapter of a laptop computer is only modestly smaller than that two decades ago, and the printed circuit board inside a smart phone must dedicate between 20% and 40% of the board area for power conversion and management. To date, efforts towards miniaturization have been limited by both materials and manufacturing challenges. To address this gap, this research will study nanomanufacturing processes to facilitate the scalable synthesis of high quality magnetic nanoparticles and nanocomposite core materials and the fabrication of compact power inductors and transformers through assembly of these nanomaterials in a manner that is compatible with current manufacturing processes, such as silicon wafer or printed circuit board fabrication. This compatibility will enable fully integrated and compact system-on-chip or system-in-package power solutions. This research will be accomplished by fostering collaboration among disciplines including materials science, chemical engineering and electrical engineering. It will foster diversity in the profession by involving high school and undergraduate students in research activities and by broadening participation through the inclusion and engagement of women and underrepresented groups.

Modeling of the Magnetic Particle Imaging Signal Due to Magnetic Nanoparticles

Magnetic Particle Imaging (MPI) is a new tomographic imaging technique that maps the spatial distribution of iron oxide magnetic nanoparticles (MNPs) in real time and with spatial resolution that is on par or better than other biomedical imaging techniques. In this project, we will develop a theoretical foundation relating the properties of MNPs and MPI magnetic field conditions to the MPI signal strength and resolution. These efforts will yield design rules that will guide the rational design of future generations of MNP tracers for MPI. The proposed research will enable development of a novel biomedical imaging technique capable of high resolution real time imaging using nontoxic tracers suitable for a variety of biomedical applications.

Directed Nanoparticle Assembly by Electrophoretic Deposition

This industry-sponsored project is funded by the MIST Center. The specific details of this project are confidential.

 

The Multi-functional Integrated System Technology (MIST) Center is an NSF Industry/University Cooperative Research Center (I/UCRC) led by the University of Florida and the University of Central Florida. Our mission is to facilitate integration of novel materials, processes, devices, and circuits into multi-functional systems through research partnerships between university, industry, and government stakeholders. With ~30 faculty participants from 6 different departments, the MIST Center serves as an early-stage research sandbox for developing next-generation smart systems in the Internet of Things era.

High-Performance CoPt Micromagnets

This industry-sponsored project is funded by the MIST Center.  The specific details of this project are confidential.

 

The Multi-functional Integrated System Technology (MIST) Center is an NSF Industry/University Cooperative Research Center (I/UCRC) led by the University of Florida and the University of Central Florida. Our mission is to facilitate integration of novel materials, processes, devices, and circuits into multi-functional systems through research partnerships between university, industry, and government stakeholders. With ~30 faculty participants from 6 different departments, the MIST Center serves as an early-stage research sandbox for developing next-generation smart systems in the Internet of Things era.

Processes for Manufacturing High-Performance Magnetic Materials in Electronic Systems

The objective of this research is to develop new manufacturing processes for the magnetic components used in modern electronic systems. The goal is improve the manufacturability, performance, and energy efficiency of power supplies and communication devices, while simultaneously reducing their size and weight. A novel process is used to combine the properties of two different magnetic materials by embedding magnetic particles of one type of material inside of a second material. The result is a new, hybrid magnetic material that exhibits improved material properties compared to existing materials. In the long run, these new magnetic materials are aimed to enable next-generation mobile electronics, communication systems, robotics, and medical devices. The project will strengthen an industry/university research partnership between the University of Florida and Electron Energy Corporation via technical exchange and a graduate student summer internship. The project also aims to broaden participation and retention of female and minority students in STEM career fields.

Ultra-High Energy Nanocomposite Capacitors

High energy density capacitors are critically important in advanced electronic devices and electric power systems that require bursts of large energy such as pace makers, defibulators, rail guns, electric vehicles and electromagnetic armor.  Our work is studying the use of nanocomposites to create ultra high energy density capacitors with particular focus on the role the morphology and orientation of the filler plays on the energy density.  Our current results have produced nanocomposites with energy density exceeding 10 J/cc, which is more than twice as large as high performance commercial materials.  Efforts to create further gains are focused on the synthesis of new high dielectric ceramic nanowires, approaches for the functionalization of the fillers to achieve improve compatibility with the polymer matrix materials and fabrication approaches to create the highest energy density capacitors available.

Spatially controlled electrospun solid gradient nanofibers for guided spiral ganglion neuron culture

The direction of cell growth is associated with chemical, structural and/or mechanical properties of the substrate. Structurally, electrospun nanofibers provide a suitable environment for cell attachment and proliferation due to their similar physical dimension to that of the extracellular matrix. Furthermore, by modulating the topographical features of nanofibers, which include fiber diameter and orientation, cell growth and its related functions can be modified. Here, we demonstrate a solid gradient scaffold for directional growth of spiral ganglion neurons (SGNs). Spatial nanofiber alignment is controlled using a custom directional electrospinning setup. The electric field to spatially control the confinement of nanofibers was simulated with COMSOL Multiphysics simulation tool and experimentally verified. To promote neurite outgrowth and impart directionality to SGN cells, a spatial gradient of neurotrophin (NT) is introduced. By sequentially electrospinning solutions of increasing concentrations of NT in the biodegradable polymer and collecting sections of these aligned fibers along a uniaxial direction, we achieved uniform sectional nanofibers of increasing gradient concentrations. Initial tests with SGNs show improved cell adhesion and decreased morbidity to microfabricated PLGA scaffolds. Our solid gradient nanofiber membrane is versatile, obviates the need for the complex microfluidic mixer system to generate an NT gradient, is potentially implantable, and can be used in other nerve regeneration studies in peripheral nerve system and central nerve system.