Mr. Ji Fang Profile

Ji Fang

Senior Engineer at Louisiana Tech Univ

SPIE Involvement:

Author

Publications (8)

Proceedings Article | 12 February 2011 Paper

A novel high-sensitive miniaturized optical system for fluorescence detection

Mingjin Yao, Ji Fang

Proceedings Volume 7908, 79080X (2011) https://doi.org/10.1117/12.873609

KEYWORDS: Light emitting diodes, Fluorescence spectroscopy, Photodiodes, Luminescence, Sensors, Optical filters, Mirrors, Point-of-care devices, Light sources, Lab on a chip

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Proceedings Article | 24 August 2010 Paper

A simple enzyme based biosensor on flexible plastic substrate

Senaka Kanakamedala, Haidar Alshakhouri, Mangilal Agarwal, Ji Fang, Mark DeCoster

Proceedings Volume 7759, 77590F (2010) https://doi.org/10.1117/12.860587

KEYWORDS: Glucose, Polymers, Sensors, Transistors, Biosensors, Electrodes, Glasses, Ions, Optical lithography, Absorbance

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Proceedings Article | 4 April 2005 Paper

Controlling nanoparticle distribution in hydrogel by electrophoresis for gradient refractive index lens applications

Weisong Wang, Ji Fang, Kody Varahramyan

Proceedings Volume 5724, (2005) https://doi.org/10.1117/12.590486

KEYWORDS: Nanoparticles, Refractive index, GRIN lenses, Particles, Electrodes, Silica, Microscopes, Silicon, Polymers, Thin films

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The principle, experiment setup and experimental results of a novel process of controlling the nanoparticle distribution in hydrogel by utilizing the theory of electrophoresis are discussed and demonstrated. The distributed nanoparticles in hydrogel changed the refractive index of the material, which provide the new application for organic gradient refractive index (GRIN) lens. For conducting the electrophoresis experiments, two miniaturized electrophoresis running tools have been designed and fabricated. The dimensions of vertical ruing tool is about 4 x 3 x 3.5 cm (L x W x H). In order to clearly observe the running results, the process of self-assembly are used to label the nanoparticles with fluorescent dye. The silica nanoparticles (7-9 nm in diameter) are being investigated to explore its effect on the optical improvement of hydrogel material. Polyacrylamide hydrogel is used as lens material. Various analysis equipments are employed to characterize the samples, including X-ray photoelectron spectroscopy (XPS), thin film measurement system and fluorescent microscopy. The experimental results from fluorescent microscope have shown that nanoparticles were moving toward the opposite charged electrode from particle resource and distributed according to the electrical field. For GRIN lens application, the electrophoresis phenomena have also been investigated by the testing setup with a circular electrode (3 cm in diameter). The testing results were examined by thin film measurement system and X-ray photoelectron spectroscopy. With the data of analyzed Si concentration, it has been proven again that the distribution of nanoparticles could be controlled by electrophoresis in hydrogel film which presents the radial gradient refractive index profiles. The refractive indices change range could be larger than 0.06. The simulation results with CoventorWare@ also predicted the nanoparticles movement and distribution in hydrogel under electrical filed with different values of electrophoretic mobilities.

Proceedings Article | 8 December 2004 Paper

Novel process to fabricate 3D microstructures joined with microchannel for microfluidic application

Weisong Wang, Jackie Chen, Ji Fang

Proceedings Volume 5591, (2004) https://doi.org/10.1117/12.569836

KEYWORDS: Photoresist materials, 3D microstructuring, Microfluidics, Lab on a chip, Surface roughness, Microelectromechanical systems, Actuators, Microfabrication, Silicon

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Proceedings Article | 17 January 2003 Paper

Investigation of hard magnetic silicone elastomer thin films

Zhongmei Yao, Ji Fang, Jackie Chen, Weisong Wang

Proceedings Volume 4982, (2003) https://doi.org/10.1117/12.478159

KEYWORDS: Thin films, Magnetism, Silicon, Silicon films, Semiconducting wafers, Photoresist materials, Microelectromechanical systems, Microfabrication, Microfluidics, Coating

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Proceedings Article | 28 September 2001 Paper

Integrated microreactor and its components for dehydrogenation of cyclohexane to benzene

Adam Reppond, Yu Liang, Ji Fang, Tianhong Cui

Proceedings Volume 4557, (2001) https://doi.org/10.1117/12.442974

KEYWORDS: Hydrogen, Silicon, Infrared sensors, Sensors, Semiconducting wafers, Platinum, Microfabrication, Palladium, Microelectromechanical systems, Gas sensors

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