David Arnold's Research Group

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.

IMG Faculty Help Launch the NSF MIST Center

The NSF Multi-functional Integrated System Technology Center (MIST Center) held it’s Kickoff Meeting on Dec. 11-12, 2014. Led by IMG faculty Dr. Nishida and Dr. Arnold, and in partnership with UCF, the mission of the MIST Center 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 inaugural membership from eight organizations, the MIST Center selected 8 projects (6 at UF and 2 at UCF) to be conducted during 2015. The UF projects are:

  • Directed Nanoparticle Assembly by Electrophoretic Deposition (PI: Dr. Arnold)
  • Laser Micromachining of 3-D Miniature Parts in Hard Materials (PI: Dr. Sheplak)
  • Technology Development for Harsh Environment Microsensors (PI: Dr. Sheplak)
  • High-Performance CoPt Micromagnets (PI: Dr. Arnold)
  • Compact Array Antennas with High Gain, Power Efficiency, and EMI Immunity in a System-in-Package Platform (PI: Dr. Yoon)
  • Ferroelectric HfO2 for Energy Storage and Non-volatile Memory Applications (PI: Dr. Nishida)

IMG Kickoff Meeting

Event date: 
Fri, 08/22/2014 - 5:00pm to 6:30pm

We will hold an IMG Kickoff meeting on Friday August 22nd in Larsen 310, starting at 1 pm, immediately after our Friday BBQ.  This meeting is mandatory for all IMG personnel.  We will provide an overview of IMG to new students, review lab organization/training, emphasize importance of the wiki, and review safety information.

IMG @ Hilton Head 2014

IMG will present six papers at the upcoming Hilton Head Workshop in June 2014 (www.hh2014.org):

  • N. Garraud and D. P. Arnold, “Characterization of the rotational dynamics of magnetic micro-discs in suspension” (poster)
  • J. Li, V. Tseng, and H. Xie, "Wafer-level fabrication of power inductors in silicon for compact dc-dc converters” (poster)
  • D. Mills, T.-A. Chen, and M. Sheplak, “A MEMS optical moiré shear stress sensor for harsh environment applications” (poster)

  • O. D. Oniku, A. Garraud, W. C. Patterson, and D. P. Arnold, “Development and modeling of a micromagnetic imprinting process” (poster)
  • W. C. Patterson, E. E. Shorman, N. Garraud, and D. P. Arnold, “A magnetic microscope for quantitative mapping of the stray fields from magnetic microstructures” (poster)
  • C. Velez, I. Torres-Díaz, O. D. Oniku, L. Maldonado-Camargo, C. Rinaldi, and D. P. Arnold, “Fabrication of Magnetic Microstructures by In Situ Crosslinking of Magnetically Assembled Nanoparticles” (poster)

Distributed Wireless Power Transmission to Compact Electronic Devices


The maintenance procedures to replace the batteries typically require physical contact or wire connections with the devices, which may be inconvenient, difficult, or costly. Even where batteries can be easily recharged, the ever-growing hunger for portable power presents an important technical challenge. For example, the modern dismounted Warfighter carries a vast array of battery-powered technologies. The logistical burden of monitoring, recharging, and replacing these batteries is overwhelming, and no soldier would willingly go on mission without fully charged batteries. For soldier power systems, there are two main issues: the large number of different electronic devices and the requirement for constant charging for maximum mission readiness.

To address these issues, the project explore the development of an electrodynamic wireless power transmission (EWPT) technology that is capable of wirelessly delivering power to a spatially distributed collection of power receivers over distances of a few centimeters to a few meters. Compared to the more widely studied inductively coupled wireless power transmission schemes, the EWPT technology enables the power receivers to be physically much smaller and with fewer restrictions on their orientation.

In the EWPT system, a transmitting coil is connected to a power source and carries an alternating current. The field generated by the transmitting coil moves a permanent magnet in the receiver through electrodynamic (magnetic) forces and/or torques. The magnet is mounted on a spring and is allowed to oscillate. This motion is then converted into electrical energy using an electrodynamic transduction within the receiver. Even using fairly weak magnetic fields, significant mechanical oscillations can be induced when the receiver magnet is excited near its mechanical resonance (assuming an underdamped mechanical system).

Magnetic Microsystems - What? Where? When? Why? How?

Event date: 
Thu, 08/29/2013 - 5:00pm to 6:00pm

As part of the Fall 2013 ECE seminar series, this Thursday, August 29, Dr. David Arnold will be giving a talk that will highlight his group's development of microfabricated permanent magnets and their application in several functional microsystems.

To set the stage, he will first describe some basic concepts about magnets and physical scaling laws that motivate his group's efforts. He'll then discuss the advancement of two types of permanent magnet materials that has been made by the group; namely, electroplated layers and bonded powders, which overcome certain manufacturing and integration challenges. Finally, He'll showcase how these permanent magnet materials are being used for electromechanical actuators, energy harvesting devices, and generation of high-energy x-rays.

As seats will be limited, all are encouraged to be on time.