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Liao H.Y.,National Key Laboratory of Fundamental Science of Micro Nano Device and System Technology | Tian P.,Chongqing University
Advanced Materials Research | Year: 2011

Water quality monitoring plays an important role in contamination control and environment protection. This paper describes an on-line multiparametric water quality monitoring system based on visible spectrophotometry, which combines embedded technology with GPRS telecommunication technology. This system can realize online wireless monitoring to concentrations of chromium (Cr), plumbum (Pb), A surfactant (AS), chemical oxygen demand (COD), ammonia nitrogen (AN), total phosphorus (TP) and total phenol (TPh) in real time. The mechanical structure, hardware circuit and software design of the system are completed. The absorption spectrums of pure water and MB-SDS complex have been measured. Preliminary experiments using a model machine show that each mechanism of the system runs well. Moreover, the monitor possesses many advantages, such as high degree of automation, high reliability, high efficiency, compact structure, small size, and so on. © (2011) Trans Tech Publications.


Yu H.,Chongqing University | Zhou J.,Key Laboratory for Optoelectronic Technology and Systems | Wang W.,National Key Laboratory of Fundamental Science of Micro Nano Device and System Technology
2014 IEEE International Conference on Electron Devices and Solid-State Circuits, EDSSC 2014 | Year: 2014

The paper presents a new hybrid micro piezoelectric-electromagnetic generator for vibration energy harvesting, which generates energy from low frequency and small amplitude vibration environment, using piezoelectric and electromagnetic conversion mechanisms. The paper outlines factors needed when designing the hybrid energy harvester, including the coupling mathematical model, the finite element analysis, optimization procedure and trade-offs. The proposed hybrid energy harvester is also fabricated and experimental results show that the device can generate an open-circuit voltage of 4.32V and produce a power of 13.47μW with an optimal resistive load of 403KΩ at 0.1 m/s2 acceleration and 105.2 Hz frequency. © 2014 IEEE.


Yu H.,Chongqing University | Yang S.,Key Laboratory for Optoelectronic Technology and Systems | Wang W.,National Key Laboratory of Fundamental Science of Micro Nano Device and System Technology
2014 IEEE International Conference on Electron Devices and Solid-State Circuits, EDSSC 2014 | Year: 2014

The paper proposes a complete energy harvesting solution integrated with a low-loss AC/DC rectifier and a high efficiency low dropout regulator (LDO) optimized for micro piezoelectric energy harvester. The AC/DC module converts AC into DC and then supplies power for the following LDO circuit module, through which the whole chip can obtain a stable 3.3V output voltage. A dynamic compensation mechanism is presented to improve the loop stability of LDO, which is easier to achieve high phase margin than traditional compensation strategy. The simulation results of LDO indicate that the typical dropout is 0.4mV with 1mA load current and 61mV with 150mA load current respectively, and the typical voltage line regulation error is 0.025%/V. In addition, the typical load regulation error was 0.00018%. The results demonstrate that the proposed chip meets the requirements of power supply for wireless sensor node (WSN). © 2014 IEEE.


Yu H.,Chongqing University | Yu H.,Key Laboratory for Optoelectronic Technology and Systems | Yu H.,National Key Laboratory of Fundamental Science of Micro Nano Device and System Technology | Zhou J.,Chongqing University | And 3 more authors.
Sensors (Switzerland) | Year: 2014

To take advantage of applications where both light and vibration energy are available, a hybrid indoor ambient light and vibration energy harvesting scheme is proposed in this paper. This scheme uses only one power conditioning circuit to condition the combined output power harvested from both energy sources so as to reduce the power dissipation. In order to more accurately predict the instantaneous power harvested from the solar panel, an improved five-parameter model for small-scale solar panel applying in low light illumination is presented. The output voltage is increased by using the MEMS piezoelectric cantilever arrays architecture. It overcomes the disadvantage of traditional MEMS vibration energy harvester with low voltage output. The implementation of the maximum power point tracking (MPPT) for indoor ambient light is implemented using analog discrete components, which improves the whole harvester efficiency significantly compared to the digital signal processor. The output power of the vibration energy harvester is improved by using the impedance matching technique. An efficient mechanism of energy accumulation and bleed-off is also discussed. Experiment results obtained from an amorphous-silicon (a-Si) solar panel of 4.8 × 2.0 cm2 and a fabricated piezoelectric MEMS generator of 11 × 12.4 mm2 show that the hybrid energy harvester achieves a maximum efficiency around 76.7%. © 2014 by the authors; licensee MDPI, Basel, Switzerland.


Liao H.-Y.,National Key Laboratory of Fundamental Science of Micro Nano Device and System Technology | Liao H.-Y.,Chongqing University | Tian P.,National Key Laboratory of Fundamental Science of Micro Nano Device and System Technology | Tian P.,Chongqing University
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010

To quickly measure the trace concentration of the single component toxic gas (e.g. sarin), a micro-array toxic gas detector is designed. A 3 × 3 gas sensor array with metalloporphyrins as sensitive materials is introduced. A micro-capsule that can be easy to be loaded and unloaded is designed for the gas reaction. A fiber-array optical path is designed, which is based on the principle that gas sensors will show different colors after reaction with the toxic gas. The tricolor information about the concentration of gas is collected by the color liner CCD. A control handling system with C8051F021 MCU as the core is implemented and embedded into the detector to perform the functions of gas sampling, data collection and analysis calculation. Data acquisition experimental results show that the proposed scheme can effectively collect the color information after gas reaction. Moreover, the system has many important advantages, such as small size, compact structure, high degree of automation, fast detection speed and high performance-cost ratio, etc. © 2010 SPIE.

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