This paper reports the formation of GaN and InN quantum dots (QDs) with symmetric spherical shapes, grown on SiN/Si(111). Spherical QDs are grown by modulating initial growth behavior via gallium and indium droplets functioning as nucleation sites for QDs. Field-emission scanning electron microscope (FE-SEM) images show that GaN and InN QDs are formed on curved SiN/Si(111) instead of on a flat surface similar to balls on a latex mattress.
View Article and Find Full Text PDFMaterials (Basel)
February 2016
Recent advances in micro/nano technology have driven artificial modifications of surface wettability by mimicking biological surfaces, such as superhydrophobic and water-harvesting surfaces. In this study, surface wettability of polycarbonate (PC) films was modified using various surface treatments: micropatterning using ultrasonic imprint lithography, fluorinate silane coating, and electron beam irradiation. To modify surface wettability selectively in a specified region, these three treatments were performed using profiled masks with the corresponding shapes.
View Article and Find Full Text PDFA single nanowire array on a chip with different materials of Palladium, Polypyrrole and Zinc Oxide has been fabricated using electrochemical deposition method. The fabricated single nanowire array has been demonstrated for highly sensitive and specific diagnosis of breast cancer by detecting four volatile organic compound biomarkers: Heptanal, Acetophenone, Isopropyl Myristate and 2-Propanol. The demonstrated sensing limits for Heptanal, Acetophenone, Isopropyl Myristate and 2-propanol using individual Palladium, Polypyrrole and Zinc Oxide nanowires were 8.
View Article and Find Full Text PDFWe have implemented a tin-oxide-decorated carbon nanotube (CNT) network gas sensor system on a single die. We have also demonstrated the deposition of metallic tin on the CNT network, its subsequent oxidation in air, and the improvement of the lifetime of the sensors. The fabricated array of CNT sensors contains 128 sensor cells for added redundancy and increased accuracy.
View Article and Find Full Text PDFWe developed a carbon nanotube (CNT)-based biosensor system-on-a-chip (SoC) for the detection of a neurotransmitter. Here, 64 CNT-based sensors were integrated with silicon-based signal processing circuits in a single chip, which was made possible by combining several technological breakthroughs such as efficient signal processing, uniform CNT networks, and biocompatible functionalization of CNT-based sensors. The chip was utilized to detect glutamate, a neurotransmitter, where ammonia, a byproduct of the enzymatic reaction of glutamate and glutamate oxidase on CNT-based sensors, modulated the conductance signals to the CNT-based sensors.
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