David B. Mast

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Electrowetting and electrocapillarity of liquid metals have a long history, and a recent explosion of renewed interest. Liquid metals have electromagnetic properties and surface tensions (>500 mN/m) that enable new forms of reconfigurable devices. However, the only nontoxic option, gallium alloys, suffer from immediate formation of a semirigid surface(More)
In this work, the effect of nanoparticle confinement on the magnetic relaxation of iron oxide (Fe3O4) nanoparticles (NP) was investigated by measuring the hyperthermia heating behavior in high frequency alternating magnetic field. Three different Fe3O4 nanoparticle systems having distinct nanoparticle configurations were studied in terms of magnetic(More)
Iron oxide exhibits fascinating physical properties especially in the nanometer range, not only from the standpoint of basic science, but also for a variety of engineering, particularly biomedical applications. For instance, Fe3O4 behaves as superparamagnetic as the particle size is reduced to a few nanometers in the single-domain region depending on the(More)
Carbon nanotube (CNT) sheet patch antennas are explored through simulation, fabrication, and measurement to evaluate the performance of the CNT material as an RF radiator. The thickness of the CNT sheet was found to have a significant impact on the radiation performance of the patch antenna due to the material skin depth, with an ~ 5.5-dB improvement to the(More)
Magnetic nanoparticles that are currently explored for various biomedical applications exhibit a high propensity to minimize total surface energy through aggregation. This study introduces a unique, thermoresponsive nanocomposite design demonstrating substantial colloidal stability of superparamagnetic Fe3O4 nanoparticles (SPIONs) due to a(More)
Carbon nanotubes (CNTs) are considered the most promising candidates to replace Cu and Al in a large number of electrical, mechanical and thermal applications. Although most CNT industrial applications require macro and micro size CNT fiber assemblies, several techniques to make conducting CNT fibers, threads, yarns and ropes have been reported to this day,(More)
A meshed carbon nanotube thread patch antenna is proposed and analyzed through full-wave electromagnetic simulation. The effects of thread spacing and of fabricating the feedline and ground-plane layers from meshed thread are explored. Results indicate that minimal impact on antenna radiation efficiency and usable bandwidth is achieved with a thread spacing(More)
Pressure-actuated liquid metal devices are demonstrated for reconfigurable electromagnetic fundamentals at GHz frequencies, including tunable dipole antennas, switchable shielding with 35-dB attenuation, ~ 30-dB polarizer attenuation, and ~ 40° diffraction from a linear grating. In addition to a wide variety of electromagnetic effects, these devices(More)
Functionalization of single-walled carbon nanotubes sSWNTsd by isotropic plasma treatment was studied using resonant Raman spectroscopy. It was shown that plasma-induced functionalization results in the uniaxial isotropic constriction of the nanotubes but preserves their overall structural integrity. It was demonstrated that NH3 ·H2O and hexamethyldisiloxan(More)
The photothermal effect of magnetite (Fe3O4) nanoparticles was characterized by photonic absorption in the near-infrared (NIR) region. Upon laser irradiation at 785 nm, the Fe3O4 nanoparticles generate localized hyperthermia in tumorous lesions, which is an effective strategy for cancer therapy; however, uncoated magnetite possesses an innate toxicity which(More)