Wang N.,Key Laboratory of Opto Electronic Technology and Systems |
Zhu Y.,Laboratory of Opto Electronic Technology and Systems |
Wei W.,Key Laboratory of Opto Electronic Technology and Systems |
Chen J.,Key Laboratory of Opto Electronic Technology and Systems |
And 3 more authors.
IEEE Sensors Journal | Year: 2012
A method to use laser to supply power remotely for multinode wireless sensor networks is proposed in this paper. In the working space of wireless sensor networks, laser is transformed to a spatial distributed light field with certain uniformity and its wavelength is converted to the most sensitive wavelength of solar cell by the phosphor element. Thus, more wireless sensor networks nodes can be powered at the same time. A demonstration experiment is carried out, an yttrium aluminum garnet phosphor element is stimulated by the 3 W 457 nm laser and a uniform diffused light field with 3 π space angle is obtained. The average optical energy density is 85 μ W/cm 2 at the distance 1.5 m away from the phosphor surface. An ultra low-power consumption energy harvesting system is designed. Under the radiation of remote laser power supply, characteristics of the energy harvesting system are tested. The result is that the system can supply 92.1 mJ during 0.7 s which can provide enough energy for WSN node. Preliminary result of a real-life application in an oil cellar is also given. As a novel power supply method for wireless sensor networks, it is a good active power supply candidate for wireless sensor networks when the environment energy field is not strong enough. © 2011 IEEE.
PubMed | Key Laboratory of Opto electronic Technology and Systems
Type: Journal Article | Journal: Sensors (Basel, Switzerland) | Year: 2012
A near-infrared spectrometer based on novel MOEMS grating light modulators is proposed. The spectrum detection method that combines a grating light modulator array with a single near-infrared detector has been applied. Firstly, optics theory has been used to analyze the essential principles of the proposed spectroscopic sensor. Secondly, the grating light modulators have been designed and fabricated by micro-machining technology. Finally, the principles of this spectroscopic sensor have been validated and its key parameters have been tested by experiments. The result shows that the spectral resolution is better than 10 nm, the wavelength deviation is less than 1 nm, the deviation of the intensity of peak wavelength is no more than 0.5%, the driving voltage of grating light modulators array device is below 25 V and the response frequency of it is about 5 kHz. With low cost, satisfactory precision, portability and other advantages, the spectrometer should find potential applications in food safety and quality monitoring, pharmaceutical identification and agriculture product quality classification.