Browsing by Author "Chang, Kai-Han"

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A biosensor of high-density lipoprotein of human serum on a liquid crystal and polymer composite film
(2013-01-01)
Lin, Yi-Hsin
;
Chang, Kai-Han
;
Chu, Wei-Lin
;
Tsou, Yu-Shih
;
Wu, Li-Ching
A biosensor for the concentration of high-density lipoprotein (HDL) in human serum on a liquid crystal and polymer composite film (LCPCF) is demonstrated. The sensing mechanism is based on a polar-polar interaction between orientation of LC directors and HDL in human serum. The concentration of polar HDL in human serum affects the orientations of LC directors at the interface between LCPCF and the human serum. In addition, the surface free energy of LCPCF changes with the applied voltage due to the electrically tunable orientations of LC directors anchored among the polymer grains of LCPCF. As a result, the droplet motion of human serum on LCPCF under applied voltages can sense the concentration of HDL in human serum.
A biosensor of high-density lipoprotein of human serum on a liquid crystal and polymer composite film
(2013-01-01)
Lin, Yi-Hsin
;
Chang, Kai-Han
;
Chu, Wei-Lin
;
Tsou, Yu-Shih
;
Wu, Li-Ching
A biosensor for the concentration of high-density lipoprotein (HDL) in human serum on a liquid crystal and polymer composite film (LCPCF) is demonstrated. The sensing mechanism is based on a polar-polar interaction between orientation of LC directors and HDL in human serum. The concentration of polar HDL in human serum affects the orientations of LC directors at the interface between LCPCF and the human serum. In addition, the surface free energy of LCPCF changes with the applied voltage due to the electrically tunable orientations of LC directors anchored among the polymer grains of LCPCF. As a result, the droplet motion of human serum on LCPCF under applied voltages can sense the concentration of HDL in human serum.
A droplet manipulation on a liquid crystal and polymer composite film as a concentrator and a sun tracker for a concentrating photovoltaic system
(2013-06-28)
Tsou, Yu-Shih
;
Chang, Kai-Han
;
Lin, Yi-Hsin
;
光電工程學系
;
Department of Photonics
We demonstrate a droplet manipulation on a liquid crystal and polymer composite film (LCPCF) as a concentrator and a sun tracker for a concentrating photovoltaic (CPV) system with a steady output electric power. The CPV system adopts a liquid lens on LCPCF whose curvature is not only tunable but position is also bistably switchable based on liquid crystal orientations on LCPCF. The change of curvature of the liquid lens results in a tunable concentration ratio which helps to increase photocurrent at a low illumination and prevent the effect of the series resistance at a high illumination. Moreover, the change of the position of the liquid lens helps to track sun owing to sun movement. Therefore, the output power of such a system is steady no matter the sunlight condition and the angle of incident light. The operating principles and experiments are investigated. The concept in this paper can be extended to design optical components for obtaining steady output power of the solar cell at indoor or outdoor use and also tracking sunlight. (C) 2013 AIP Publishing LLC.
An electrically switchable surface free energy on a liquid crystal and polymer composite film
(2012-12-03)
Lin, Yi-Hsin
;
Chu, Ting-Yu
;
Tsou, Yu-Shih
;
Chang, Kai-Han
;
Chiu, Ya-Ping
An electrically switchable surface free energy on a liquid crystal and polymer composite film (LCPCF) resulting from the orientations of liquid crystal molecules is investigated. By modification of Cassie's model and the measurement based on the Chibowski's film pressure model (E. Chibowski, Adv. Colloid Interface Sci. 103, 149 (2003)), the surface free energy of LCPCF is electrically switchable from 36 x 10(-3)J/m(2) to 51 x 10(-3)J/m(2) while the average tilt angle of LC molecules changes from 0 degrees to 32 degrees with the applied pulsed voltage. The switchable surface free energy of LCPCF can help us to design biosensors and photonics devices, such as electro-optical switches, blood sensors, and sperm testers. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4769093]
Analysis of a 50 kW organic Rankine cycle system
(2011-10-01)
Kuo, Chi-Ron
;
Hsu, Sung-Wei
;
Chang, Kai-Han
;
Wang, Chi-Chuan
;
機械工程學系
This study analyzes the system performance of a 50 kW ORC system subject to influence of various working fluids. A dimensionless "figure of merit" combining the Jakob number, condensing temperature, and evaporation temperature is proposed for quantitatively screening working fluid as far as thermal efficiency is concerned. The thermal efficiency normally decreases with the rise of figure of merit, and the predictive ability of the proposed figure of merit is not only applicable to the present eighteen working fluids but is also in line with some existing literatures. Analysis of the typical ORC heat exchangers indicates that the dominant thermal resistance in the shell-and-tube condenser is on the shell side. Similarly, the dominant resistance is also on the refrigerant side for the plate evaporator. However, there is a huge difference of thermal resistance amid working fluid and water side in the preheating zone. Conversely, only a minor difference exists in the evaporation region. The extremely uneven resistance distribution in the plate heat exchanger can be resolved via an additional preheater having significant augmentation in the working fluid. (C) 2011 Elsevier Ltd. All rights reserved.