- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Photoelectric evaluation of dye-sensitized solar cells based on prodigiosin pigment derived from Serratia marcescens 11E
摘要： Prodigiosin, a natural pigment produced as a secondary metabolite by the non-photosynthetic bacterium Serratia marcescens, was tested as a sensitizer in dye-sensitized solar cells (DSSC). The strain S. marcescens 11E, which was isolated from a natural spring located in the northeastern Mexican state of Nuevo Leon, was cultivated on peanut oil broth 1% v/v, a culture medium which is known to enhance the production of prodigiosin. The resulting pigment was extracted with chloroform and identified as prodigiosin based on the spectroscopic and structural characteristics obtained by UV–Vis spectrophotometry along with FTIR and 1H-NMR spectroscopies. The initial absorbance decomposition test performed on the bacterial pigment demonstrated that prodigiosin exhibited high photostability after five days, while the photovoltaic performance test of the sensitized DSSC, resulted in an open voltage circuit of 560 mV, a current density of 0.096 mA/cm2, and efficiency of 0.032 %. Structurally, the DSSC consisted of a titanium dioxide (TiO2) photoanode sensitized with the pigment by direct adsorption, an electrolyte containing a redox pair I?/I3? and a cathode or counter electrode prepared from a carbon paste. Since the overproduction of prodigiosin can be easily achieved on a large scale through the rapid fermentation of agro-industrial residues throughout the year without the need to allocate surfaces for the cultivation of pigment-producing plants or wait for specific seasons for their cultivation, our results suggest that prodigiosin could be considered an excellent candidate to be used in the development of a low-tech, low-cost DSSC.
关键词： Low-cost DSSC,Solar energy,Bacterial pigments,Native strain
更新于2025-09-23 15:19:57
-
Optical Mouse Sensor for Eye Blink Detection and Pupil Tracking: Application in a Low-Cost Eye-Controlled Pointing Device
摘要： In this paper, a new application of the optical mouse sensor is presented. The optical mouse is used as a main low-cost infrared vision system of a new proposal of a head-mounted human-computer interaction (HCI) device controlled by eye movements. The default optical mouse sensor lens and illumination source are replaced in order to improve its ?eld of view and capture entire eye images. A complementary 8-bit microcontroller is used to acquire and process these images with two optimized algorithms to detect forced eye blinks and pupil displacements which are translated to computer pointer actions. This proposal introduces an inexpensive and approachable plug and play (PnP) device for people with severe disability in the upper extremities, neck, and head. The presented pointing device performs standard computer mouse actions with no extra software required. It uses the human interface device (HID) standard class of the universal serial bus (USB) increasing its compatibility for most computer platforms. This new device approach is aimed at improving comfortability and portability of the current commercial devices with simple installation and calibration. Several performance tests were done with di?erent volunteer users obtaining an average pupil detection error of 0.34 pixels with a successful detection in 82.6% of all mouse events requested by means of pupil tracking.
关键词： human-computer interaction,low-cost device,optical mouse sensor,pupil tracking,eye blink detection
更新于2025-09-23 15:19:57
-
[IEEE 2019 24th Microoptics Conference (MOC) - Toyama, Japan (2019.11.17-2019.11.20)] 2019 24th Microoptics Conference (MOC) - Three-dimensional observation of polymer and liquid crystal director in highly oriented liquid crystal / polymer composite films which show electro-optical transparency-turbidity switching
摘要： Cameras embedded in consumer devices have previously been used as physiological information sensors. The waveform of the photoplethysmographic image (PPGi) signals may be significantly affected by the light spectra and intensity. The purpose of this paper is to evaluate the performance of PPGi waveform acquisition in the red, green, and blue channels using a commercial camera in different light conditions. The system, developed for this paper, comprises of a commercial camera and light sources with varied spectra and intensities. Signals were acquired from the fingertips of 12 healthy subjects. Extensive experiments, using different wavelength lights and white light with variation light intensities, respectively, reported in this paper, showed that almost all light spectra can acquire acceptable pulse rates, but only 470-, 490-, 505-, 590-, 600-, 610-, 625-, and 660-nm wavelength lights showed better performance in PPGi waveform compared with gold standard. With lower light intensity, the light spectra >600 nm still showed better performance. The change in pulse amplitude (ac) and dc amplitude was also investigated with the different light intensity and light spectra. With increasing light intensity, the dc amplitude increased, whereas ac component showed an initial increase followed by a decrease. Most of the subjects achieved their maximum averaging ac output when averaging dc output was in the range from 180 to 220 pixel values (8 b, 255 maximum pixel value). The results suggested that an adaptive solution could be developed to optimize the design of PPGi-based physiological signal acquisition devices in different light conditions.
关键词： Photoplethysmographic image,light intensity,light spectrum,low-cost camera
更新于2025-09-19 17:13:59
-
3-D-Printed Modified Butler Matrix Based on Gap Waveguide at W-Band for Monopulse Radar
摘要： This article presents the design and fabrication of low-loss, -weight, and -cost, modified Butler matrix in groove gap waveguide technology at W-band, implemented by additive manufacturing. The design, simulations, and measurements of the elements that conform to the modified Butler each of matrix are presented. The proposed modified Butler matrix is asymmetric and oriented to an easy assembly with a radial antenna in order to obtain simultaneous sum and difference patterns for a narrowband radar application. The measured individual components of the modified Butler matrix fit very well with the simulations. As for the full modified Butler matrix, measurements provide a 0.7% bandwidth below ?20 dB for sum and difference ports centered at 94 GHz. The amplitude and phase imbalance are below 1.5 dB and 20?, respectively. This narrow bandwidth is due to the difference in length between input and output ports due to the asymmetry of the design. The total losses of the modified Butler matrix are below 1 dB.
关键词： low profile,distribution network,Additive manufacturing,butler matrix,low cost,W-band,point-to-point communications,low weight,groove gap waveguide (GGW),radar,low loss,monopulse,space debris
更新于2025-09-16 10:30:52
-
Giant detectivity of ZnO-based self-powered UV photodetector by inserting an engineered back gold layer using RF sputtering
摘要： The realization of high-responsivity, self-powered and low-cost ultraviolet (UV) photodetector (PD) based on eco-friendly and earth-abundant compounds, remains far from satisfactory for future optoelectronic applications. In this paper, we demonstrated a new high-performance UV-PD based on planar ZnO thin-film, efficiently operating without any power supply. The proposed device was elaborated by evaporating an engineered back metallic layer onto the glass substrate and then depositing ZnO thin layer through RF sputtering technique. The sensor structural and optical properties were systematically analyzed by the techniques of X-ray diffraction (XRD) and UV–Vis absorbance spectrometry. The resulted ZnO UV-PD showcased a clear and distinctive photovoltaic behavior. Interestingly, it also demonstrated a high responsivity of 0.38A/W and a giant detectivity exceeding 1014 Jones at zero bias, which is much higher than other reported self-powered UV-PD despite the use of an All-ZnO structure. The device photodetecting mechanism in self-driven mode was discussed using the energy band diagram, where the key role of the engineered back metallic layer in modulating the electric field distribution within the ZnO active region to effectively achieve an asymmetric behavior is emphasized. Therefore, the presented work offers a novel pathway to design high-responsivity self-powered UV-PDs based on a simple All-ZnO structure.
关键词： detectivity,ZnO,Self-powered,low cost,UV photodetectors,RF sputtering
更新于2025-09-16 10:30:52
-
Low-cost and highly accessible technology based on radially polarized beam-excited plasmonic microfiber for label-free Raman detection
摘要： A low-cost and highly accessible method for high sensitivity label-free Raman spectroscopy based on a cylindrical metalized microfiber internally excited via a radially polarized beam (RPB) has been developed. A silver (Ag)-pyramid coated microfiber was designed to be matched with the RPB. Simulation results show that the enhancement of the electric-field intensity of the cylindrically metalized microfiber excited by the RPB can reach a factor of 2.5 × 103, which is much higher than that of linearly polarized beam (LPB) excitation. In experiments, the RPB is directly generated in the optical fiber by converting the LPB to an RPB using electrically controllable, low cost acoustic-optical technology. An Ag-pyramid coated microfiber with ～9.6 μm diameter was prepared using a simple Ag-mirror reaction. The Raman intensity for malachite green (MG) detected by the Ag-pyramid coated microfiber under RPB excitation was 5 times stronger than that under LPB excitation. The Raman sensitivity for MG in the case of RPB excitation was as low as 10?10 M, a concentration level which was not detectable for LPB excitation. The sensor system gave high repeatability and reliability and should find application in high sensitivity label-free detection in optical sensing with the advantages of low-cost and ease of operation.
关键词： low-cost,label-free Raman spectroscopy,radially polarized beam,highly accessible,plasmonic microfiber
更新于2025-09-16 10:30:52
-
[IEEE 2019 European Space Power Conference (ESPC) - Juan-les-Pins, France (2019.9.30-2019.10.4)] 2019 European Space Power Conference (ESPC) - Qualification of low cost triple junction GaInP/GaAs/Ge solar cell assemblies with external bypass diode connected by insulated cell P/diode N interconnects
摘要： CESI has combined the high efficiency, radiation hardness and reliability of the III-V compound triple junction solar cells with a low cost approach developing a peculiar triple junction solar cell targeting 28% efficiency, radiation hardness typical of this class of solar cells and at the same time a significant cost advantage. Such solar cells have recently passed the LEO and GEO qualification according to the ECSS standard at bare cell level and are currently under GEO and LEO qualification as solar cell assemblies.
关键词： III-V compound solar cells,low cost,Space solar cells,solar cells assembly
更新于2025-09-16 10:30:52
-
[IEEE 2019 International Conference on Electrical, Communication, and Computer Engineering (ICECCE) - Swat, Pakistan (2019.7.24-2019.7.25)] 2019 International Conference on Electrical, Communication, and Computer Engineering (ICECCE) - Optimization of Efficient Copper-Indium-Gallium Di-Selenide Solar Cell
摘要： The implementation of Copper Indium Gallium Selenide (CIGS) based solar cells have been simulated through software. A novel model FTO/ZnSe/CIGS/Mo/Substrate has been proposed by using a GPVDM. In this investigation, the main focus is to analyze low cost material and optimize it for better efficiency as compare to conventional CIGS solar cells. We observed in our findings that as the thickness of CIGS medium increases, the power conversion efficiency affectively increases. Also, different material testing was also formed for windows and buffer layer, where it has been observed that efficient model must have window layer Fluorine tin oxide (FTO) and buffer layer is Zinc selenide (ZnSe) with thickness of 30nm and 20nm, respectively. Moreover, solar cell with these topographies gives conversion efficiency of 18.51%.
关键词： Thin film Solar Cell,CIGS,GPVDM,low cost
更新于2025-09-16 10:30:52
-
Freestanding and supported processing of sub-70 μm kerfless epitaxial Si and thinned Cz/FZ Si foils into solar cells: An overview of recent progress and challenges
摘要： Utilisation of expensive silicon (Si) material in crystalline Si modules has come down to 4 g Si per watt-peak in 2018, mainly as a result of reduction in wafer thickness and kerf losses as well as increase in module efficiencies. With continued progress in conventional multi-wire sawing of ingots, wafers as thin as 100 μm could eventually be produced. Beyond this, kerfless lift-off technologies are being investigated which enable wafer thicknesses well below 100 μm with negligible Si kerf waste. Such thin Si wafers and foils would be much lighter in weight than today's standard 165-180 μm-thick wafers and would exhibit considerable flexibility and fragility. This necessitates a rethink about how to handle and process thin Si into solar devices in a manufacturing line with high mechanical yield and high throughput. This paper gives a broad overview of the different approaches for fabricating solar cells on thin Si foils. In particular, three routes are discussed in detail, namely (1) freestanding processing of thin Si, (2) processing of thin Si supported mechanically on a conductive low-cost Si substrate (“wafer-equivalent” approach) and (3) processing of thin Si bonded to a transparent glass superstrate. In each case, the main challenges are explained and the recent progress in addressing them are summarised. Kerfless 50 μm-thick epitaxial Si foils lifted-off using porous Si and thinned-down Si wafers (below 70 μm) are used as model substrates for this work.
关键词： Fragility,Layer transfer,Breakage,Lift-off,Glass superstrate,Thin silicon foils,Supported processing,Epitaxial silicon,Bonding,Adhesive,Wafer-equivalent,Low-cost silicon substrate,Flexibility,Kerfless,Freestanding
更新于2025-09-16 10:30:52
-
Low-cost Custom Fabrication and Mode-locked Operation of an All-normal-dispersion Femtosecond Fiber Laser for Multiphoton Microscopy
摘要： A protocol is presented to build a custom low-cost yet high-performance femtosecond (fs) fiber laser. This all-normal-dispersion (ANDi) ytterbium-doped fiber laser is built completely using commercially available parts, including $8,000 in fiber optic and pump laser components, plus $4,800 in standard optical components and extra-cavity accessories. Researchers new to fiber optic device fabrication may also consider investing in basic fiber splicing and laser pulse characterization equipment (~$63,000). Important for optimal laser operation, methods to verify true versus apparent (partial or noise-like) mode-locked performance are presented. This system achieves 70 fs pulse duration with a center wavelength of approximately 1,070 nm and a pulse repetition rate of 31 MHz. This fiber laser exhibits the peak performance that may be obtained for an easily assembled fiber laser system, which makes this design ideal for research laboratories aiming to develop compact and portable fs laser technologies that enable new implementations of clinical multiphoton microscopy and fs surgery.
关键词： fiber laser,multiphoton microscopy,low-cost,mode-locking,Issue 153,femtosecond pulsed laser,Engineering,custom fabrication
更新于2025-09-12 10:27:22