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Micromechanical resonators are promising replacements for quartz crystals for timing and frequency references owing to potential for compactness, integrability with CMOS fabrication processes, low cost, and low power consumption. To be used in high performance reference application, resonators should obtain a high quality factor. The limit of the quality(More)
This paper reports the use of movable electrodes that can be electrostatically pulled in to achieve narrow gaps beyond lithography / etch capabilities. Width-extensional resonators with frequencies of 50 MHz and quality factors of 150k are demonstrated with such movable electrodes to have a significantly lower motional impedances when pull-in occurs.(More)
A series of nanocomposites consisting of zero-valent iron nanoparticles (ZVI NPs) encapsulated in SiO2 microspheres were successfully synthesized through a successive two-step method, i.e., the wet chemical reduction by borohydride followed by a modified Stöber method. The as-synthesized nanocomposites were characterized using X-ray diffraction, field(More)
(b) Figure 2. 45° SEM images of an encapsulated device free from etch perforations, from (a) the top side and (b) the underside. Figure 1. Process for releasing large device areas without etch holes and controlling the doping concentration via epitaxial deposition, with epi-seal encapsulation. ABSTRACT A process is presented for the fabrication of high(More)
CeO2 nanoparticles (NPs) have been well demonstrated as an antioxidant in protecting against oxidative stress-induced cellular damages and a potential therapeutic agent for various diseases thanks to their redox enzyme-mimicking activities. The Ce(3+)/Ce(4+) ratio and oxygen vacancies on the surface have been considered as the major originations responsible(More)
In this work, a novel agarose gel electrophoresis strategy has been developed for separation of DNA fragments by doping graphene oxide (GO) into agarose gel. The results show that the addition of GO into agarose gel significantly improved the separation resolution of DNA fragments by increasing the shift distances of both the single DNA fragments and the(More)
A series of PtM (M=Co, Ni)/reduced graphene oxide (rG-O) nanocomposites were successfully synthesized through a facile hydrothermal method. The as-synthesized nanocomposites were characterized using transmission electron microscopy and high-resolution transmission electron microscopy, X-ray diffraction, inductively coupled plasma-atomic emission(More)
In this study, Pt3Ni microspheres consisted of nanoparticles were synthesized without addition of surfactants via the solvothermal route. The obtained sample was characterized by X-ray diffraction (XRD), inductively coupled plasma-atomic emission spectrometer (ICP-AES), X-ray photoelectron spectroscopy (XPS), and field-emission scanning electron microscopy(More)
In this paper, we present measurements of the nonlinear amplitude-frequency (A-f) coefficients for three types of bulk-mode silicon MEMS resonators with different doping type and concentration. Our experimental results clearly show a strong dependence of the nonlinearity character on the orientation, doping level, and vibrational mode shape. These results(More)
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