Browsing by Author "Chen, Hung-Che"

Now showing 1 - 6 of 6

A New Automatic Readout Circuit for a Gas Sensor with Organic Vertical Nanojunctions
(2016)
Chen, Hung-Che
;
Kao, Yung-Hua
;
Chao, Paul C. -P.
;
Wey, Chin-Long
;
電子工程學系及電子研究所
The design of the proposed readout circuit provides benefits of detection speed, portability, low-cost and less human operational errors compared with the measurement by traditional instruments. Thus the added value is brought for bio-sensors and applied in home care. A novel readout circuit for a gas sensor based on an organic diode with vertical nano junctions (VNJ) is proposed in this study. There are seven parts included in the readout system. First part is a preamplifier, second part is a peak-detect-and-hold circuit, third part is a divider, fourth part is the saturation detector, fifth part is the auto-reset circuit, sixth part is a logic gate and a buffer, seventh part is a micro-processor control unit (MCU). STM32 is the CPU of proposed MCU by ALIENTEK. The ADC of MCU is used to transform the output data of readout circuit. The designed circuit is accomplished by Taiwan Semiconductor Manufacturing Company (TSMC) 0.35 mu m 2P4M 3.3 V mixed - signal CMOS process, the area of chip is 0.74x0.75 mm(2). Finally, the differences between experimental results with post simulation results in 10 ppb similar to 3 ppm of ammonia, the differences are within 7.24%. The sensing system is able to detect minimum ammonia concentration of 10 ppb, while the maximum one reaches around 3 ppm.
A New Gas Sensor of a Thin-Film Diode and Low-Power, Area-Efficient Readout Circuit
(2013)
Chen, Hung-Che
;
Chao, Paul C. -P.
;
Lin, Wei-Chu
;
Sun, Hsiang-Fang
;
Dai, Ming-Zhi
The study presents a new gas sensor made of a novel organic diode with vertical nano-junctions and its low-power, area-efficient readout circuit. There are seven parts included in the readout system. First part is a preamplifier, which is composed of trans-impedance to convert the output current of a gas sensor into voltage. Second part is a peak-detect-and-hold circuit. It can detect the maximum voltage and holds its value, the initial value. Third part is a divider, which is used to calculate the ratio of saturation current to initial current. Fourth part is the saturation detector, which is used to detect when the output current of the VNJ-P3HT diode doesn\'t change anymore (that is, the responses are saturated). Fifth part is the auto-reset circuit, which is used to detect when the sensor device starts to react with gas and reset the voltage value of the peak detect-and-hold circuit. Sixth part is a logic gate and a buffer. When the sensor device is reacting with gas and the responses are saturated, the response result is outputted through the logic gate and buffer. Otherwise, the zero is outputted. Seventh part is a micro-processor control unit (MCU). STM32 is the CPU of proposed MCU by ALIENTEK. The ADC of MCU is used to transform the output data of readout circuit. Then the LCD displays the results. The designed circuit is accomplished by Taiwan Semiconductor Manufacturing Company (TSMC) 0.35 mu m 2P4M 3.3V mixed-signal CMOS process.
Integrated multiple multi-photon imaging and Raman spectroscopy for characterizing structure-constituent correlation of tissues
(2008-10-13)
Jhan, Jhen-Wei
;
Chang, Wei-Tien
;
Chen, Hung-Che
;
Lee, Yu-Tsung
;
Wu, Ming-Fang
Histopathological imaging of tissues often requires extensive sample preparation including fixation and staining in order to highlight characteristic alterations associated with diseases. Herein, we report an integrated spectro-microscopy approach based on a combination of multimodal multi-photon imaging and Raman micro-spectroscopy and demonstrate label-free characterization of the structure-constituent correlation of porcine skin. The multi-modal imaging allows the visualization of dermatological features whereas Raman micro-spectroscopy enables the identification of their 'molecular fingerprints'. By obtaining both structural and molecular-level information of tissue constituents, this integrated approach can offer new insight into the patho-physiological status of tissues. (c) 2008 Optical Society of America
Optical biopsy of atherosclerotic lesions using integrated second-harmonic and nonlinear Raman microscopy
(2008-06-01)
Chang, Wei-Tien
;
Jhan, Jhen-Wei
;
Wu, Yao-Ming
;
Chen, Hung-Che
;
Liau, Ian
Quantitative Assessment of Hepatic Fat of Intact Liver Tissues with Coherent Anti-Stokes Raman Scattering Microscopy
(2009-02-15)
Wu, Yao-Ming
;
Chen, Hung-Che
;
Chang, Wei-Tien
;
Jhan, Jhen-Wei
;
Lin, Hung-Lung
A fatty liver might progress from being a benign fatty liver, to steatohepatitis, cirrhosis, or even hepatocellular carcinoma. The great prevalence and severe outcome have warranted much investigation of the pathology and the development of effective therapies, which involve animal studies requiring critical evaluation of the hepatic fatty change. Histological examination and wet chemical analysis of liver biopsy specimens are generally employed for this purpose despite numerous procedures being involved. Using coherent anti-Stokes Raman scattering (CARS) microscopy, we have demonstrated the specific imaging of fat droplets in intact liver tissues and extracted the hepatic fat content through image analysis while eliminating laborious procedures required by traditional histopathological. examination. The content of hepatic fat measured with CARS imaging was correlated strongly with that determined by biochemical analysis (R(2) = 0.89) over a pathologically significant range of the hepatic fat (from 2% to 20% of the total mass of tissue). Our work validates the quantitative assessment of fat in intact tissue through the use of CARS microscopy. When combined with the increasingly diverse animal models of diseases related to metabolic disorders of lipids, our approach is extensible to enable acquiring important insight into the genetic, environmental, and dietary factors affecting the uptake and accumulation of fat within tissues.
Real-time molecular assessment on oxidative injury of single cells using Raman spectroscopy
(2009-09-01)
Chang, Wei-Tien
;
Lin, Hung-Lung
;
Chen, Hung-Che
;
Wu, Yao-Ming
;
Chen, Wen-Jone
Oxidative stress is encountered in many biological systems; the resultant oxidative injury plays a significant role in the pathogenesis of diverse diseases. Conventional measurements on oxidative injury are employed almost exclusively on a large population of cells either by counting the fraction of cell death or by observing the fluorometric change resulting from exogenous reagents, thereby lacking in molecular detail and temporal specificity. In this work we combine laser tweezers and Raman spectroscopy to observe the response of single cells to oxidative stress. By measuring the temporal changes of vibrational spectra of single optically trapped cells, we demonstrate a molecular-level assessment of cellular oxidative injury in real time, both qualitatively and quantitatively, without the introduction of exogenous reagents. The main experimental findings are supported by the observation of Raman spectra of intermediates and downstream products. The abrogation of the above changes by ascorbic acid further illustrates the therapeutic effect of antioxidants against cellular oxidative injury. This approach is extensible to studies exploring the biochemical transformation of single cells or intracellular organelles in response to various chemical or physical stimuli. With the aid of 'molecular fingerprints', single-cell Raman spectroscopy exhibits a great potential for accessing the chemical aspects of cellular bioactivity, yielding insight into pathophysiological processes and assisting the development of novel therapeutic interventions against diseases. Copyright (C) 2009 John Wiley & Sons, Ltd.