A5001155732- Innovative Energy Harvesting Technologies
- Energy Harvesting in Wireless Networks
- Wireless Power Transfer Systems
- Magnetic properties of thin films
- Electric Motor Design and Analysis
- Advanced MEMS and NEMS Technologies
- Characterization and Applications of Magnetic Nanoparticles
- Magnetic Properties and Applications
- Mechanical and Optical Resonators
- Magnetic Properties of Alloys
- Plasma and Flow Control in Aerodynamics
- Advanced Sensor and Energy Harvesting Materials
- Micro and Nano Robotics
- Microfluidic and Bio-sensing Technologies
- Magnetic Properties and Synthesis of Ferrites
- Modular Robots and Swarm Intelligence
- Metallic Glasses and Amorphous Alloys
- Copper Interconnects and Reliability
- Acoustic Wave Resonator Technologies
- Electromagnetic wave absorption materials
- Electrodeposition and Electroless Coatings
- Silicon Carbide Semiconductor Technologies
- Advanced Materials and Mechanics
- Acoustic Wave Phenomena Research
- Aerosol Filtration and Electrostatic Precipitation
University of Florida
2016-2025
Fermi National Accelerator Laboratory
2022
Kelvin Nanotechnology (United Kingdom)
2021
Gainesville Obstetrics & Gynecology
2020
Institute for Social and Economic Research
2017
North Central Organized Regionally For Total Health
2017
Cornell University
2017
Microsystems (United Kingdom)
2016
Institute for Stem Cell Biology and Regenerative Medicine
2014
London South Bank University
2014
This paper discusses the history, current state of art, and ongoing challenges for compact (less than a few cubic centimeters) magnetic power generation systems in microwatts to tens watts range. These are great interest powering sensor networks, robotics, wireless communication systems, other portable electronics. The considers following topics. 1) theoretical practical implications miniaturizing generators. 2) design performance previously demonstrated devices, which summarized compared....
Decades of research focused on size and shape control iron oxide nanoparticles have led to methods synthesis that afford excellent over physical but comparatively poor magnetic properties. Popular based thermal decomposition organometallic precursors in the absence oxygen yielded particles with mixed phases, crystal defects, poorer than expected properties, including existence a thick "magnetically dead layer" experimentally evidenced by diameter significantly smaller diameter. Here, we show...
This paper reviews the state of art for microfabrication permanent magnets applicable to microelectromechanical systems (MEMS). Permanent are a key building block realization magnetically based MEMS sensors, actuators, and energy converters. In this paper, basic theories operational concepts first described. Then, different classes permanent-magnet materials associated performance tradeoffs introduced. Challenges relating integration into applications then discussed. Last, summary review...
This paper presents a simple, compact, and low-power method for generating extremely low-frequency radio signals below ~500 Hz. is motivated by the prohibitively large size low efficiency of conventional antennas operating in this frequency range. The successful generation time-varying magnetic fields produced physical rotation 3 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> permanent magnet demonstrated. Ground plane receiver...
Stiffness and forces are two fundamental quantities essential to living cells tissues. However, it has been a challenge quantify both 3D traction stiffness (or modulus) using the same probe in vivo. Here, we describe an approach that overcomes this by creating magnetic microrobot with controllable functionality. Biocompatible ferromagnetic cobalt-platinum microcrosses were fabricated, each microcross (about 30 micrometers) was trapped inside arginine–glycine–aspartic acid–conjugated stiff...
In this work, non-resonant, vibrational energy harvester architectures intended for human-motion scavenging are researched. The basic design employs a spherical, unidirectionally magnetized permanent magnet (NdFeB) ball that is allowed to move arbitrarily in spherical cavity wrapped with copper coil windings. As the rotates and translates within cage, time-varying magnetic flux induces voltage according Faraday's Law. Devices ranging from 1.5 cm3 4 size were tested under human activity...
This paper presents an input-powered energy-harvesting interface circuit that eliminates standby power consumption by automatically shutting down when the ac input voltage amplitude is too low for successful energy reclamation. feature need precharging load and allows indefinitely long intervals between harvesting cycles. The comprises two subcircuits: ac/dc converter dc/dc boost with regulated output. subcircuits are separately fabricated in ON Semi 3M-2P 0.5 μm CMOS process. entire starts...
This paper presents the microfabrication and measurement of high-inductance-density, moderate-Q, air-core inductors, transformers intended for switch-mode power supplies operating in 100-500 MHz frequency range. The inductors were fabricated on Pyrex substrates with four layers electrodeposited copper each layer up to 10 ¿m thick. Stacked winding allowed mutual coupling between increase areal inductance density. Inductors various designs exhibited densities 100 nH/mm <sup...
This paper develops and analyzes an equivalent circuit model of magnetic energy harvesters using reduced-order lumped element modeling (LEM) methods. is intended to enhance the design analysis a harvesting system by enabling direct physical insight into dynamics simple techniques extract all relevant performance parameters. Moreover, provides ability use simulation software (e.g. PSPICE) entire in conjunction with nonlinear and/or active power electronic circuits. The experimentally...
Kelvin's formula is used to calculate forces acting on a permanent magnet in the presence of an external magnetic field from second magnet. This approach derive explicit analytical solutions for axial and lateral between cuboidal cylindrical magnets as functions dimensions separation. While exact can be found magnets, hypergeometric expansion approximate elliptic integrals solving fields magnets. The resulting equations are applied over range sizes geometries explore scaling laws other...
This paper theoretically and experimentally investigates an ac/dc converter for low-voltage vibrational energy harvesting systems. The circuit employs active-diode-based voltage doubler, where the output is a dc that twice amplitude of input ac voltage. Analytical solutions steady-state open-circuit are derived, capturing effects active-diode comparator hysteresis. It shown hysteresis plays important role in rectification characteristics, stability, overall efficiency. Experimentally, able...
We report the design, fabrication, and experimental characterization of first fully 3D-printed, multi-material miniature magnetic actuators for compact systems in literature. The actuator design integrates a bonded hard magnet made NdFeB microparticles embedded Nylon 12 matrix (55% by volume) with structural support elements pure 12. device is 10 mm-diameter, 1.2 mm wall-thick, 9 tall cylindrical frame that mounts on an off-the-shelf solenoid diameter, 100 μm-thick, leak-tight membrane...
In this work, a composite of barium ferrite (BaM) and multiwalled carbon nanotubes (CNTs) in polymer matrix polydimethylsiloxane (PDMS) are reported for the purpose suppressing electromagnetic interference (EMI). Shielding is accomplished primarily through absorption, which arises from combination ferromagnetic resonance (FMR) BaM conductive losses CNTs. The fabricated by mixing commercially available nanoparticles CNTs into PDMS, screen printing mixture molds, then curing at 80 °C DC...
Abstract The MANTA (Modular Adjustable Negative Triangularity ARC-class) design study investigated how negative-triangularity (NT) may be leveraged in a compact, fusion pilot plant (FPP) to take ‘power-handling first’ approach. result is pulsed, radiative, ELM-free tokamak that satisfies and exceeds the FPP requirements described 2021 National Academies of Sciences, Engineering, Medicine (NASEM) report ‘Bringing Fusion U.S. Grid’ (2021 Bringing Grid ). A self-consistent integrated modeling...
This paper presents the development of a floating-element-based capacitively sensed direct wall-shear-stress sensor intended for measurements in turbulent boundary layer. The design principle is presented, followed by details fabrication, packaging, and characterization process. designed with an asymmetric comb finger structure metalized electrodes. fabrication process uses deep reactive ion etching on silicon-on-insulator wafer, resulting simple two-mask dynamically characterized...
This paper theoretically and experimentally investigates voltage enhancement effects using a multi-pole magnet array in magnetic energy harvester. The use of multiple poles is shown to increase the frequency amplitude output voltage, addressing one primary disadvantages transduction schemes, especially for low-frequency vibrations. Experimental results from four-pole prototype demonstrate three times improvement rms as compared conventional single-magnet designs along with up-conversion...
A microfabrication technique is reported for the fabrication of wax-bonded micromagnets in 100μm–1mm range. This dimensional size not typically achievable by thin-film deposition techniques or conventional macroscale magnet processing, and interest magnetic microelectromechanical systems applications. The approach incorporates a wax powder binder to “lock” microparticles together improve coercivity. In practice, NbFeB are packed into pre-etched trenches silicon wafer subsequently heated,...
A near-field, electrodynamically coupled wireless power transmission system is presented that delivers electrical from a transmitter coil to compact electromechanical receiver. The integrates energy conversion and mechanical resonance deliver over range of distances using low-amplitude, low-frequency magnetic fields. Two different receiver orientations are investigated rely on either the force or torque induced magnet at separation ranging 2.2 10.2?cm. Theoretical models for each mode...
This paper demonstrates a highly efficient, low-voltage ac/dc converter using voltage multiplier (octupler) circuit architecture intended for vibrational energy harvesting applications where ac waveform is used to charge battery. The employs output-powered active diodes and does not require any external power supply or startup circuitry. rectifies boosts input voltages in the range of 0.35-2 V 20-500 Hz dc output, that is, ~8 times higher than amplitude. can cold start from an 0.5 higher,...
This article describes a versatile method to fabricate magnetic microstructures with complex two-dimensional geometric shapes using magnetically assembled iron oxide (Fe3O4) and cobalt ferrite (CoFe2O4) nanoparticles. Magnetic pole patterns are imprinted into magnetizable media, onto which nanoparticles from colloidal suspension defined via the shaped field gradients. The kinetics of this assembly process studied by evaluation microstructure features (e.g., line width height) as function...
The dynamic magnetization of immobilized spherical single-domain magnetic nanoparticles (MNPs) with uniaxial or cubic magnetocrystalline anisotropy was studied computationally by executing simulations based on the Landau-Lifshitz-Gilbert (LLG) equation. For situations when a static field suddenly applied and then removed, effects particle diameter (considering both type symmetry characteristic energy) relaxation time were parametrically. results, for symmetries, show that is turned off MNPs...