scholarly journals Greyscale and Paper Electrochromic Polymer Displays by UV Patterning

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 267 ◽  
Author(s):  
Robert Brooke ◽  
Jesper Edberg ◽  
Xavier Crispin ◽  
Magnus Berggren ◽  
Isak Engquist ◽  
...  
Keyword(s):  
Uv Light ◽  
Low Cost ◽  
Color Space ◽  
Optical Memory ◽  
Electrochromic Devices ◽  
Smart Windows ◽  
Energy Efficient Buildings ◽  
Oxidant Concentration ◽  
High Resolution Images ◽  
Vapor Phase Polymerization

Electrochromic devices have important implications as smart windows for energy efficient buildings, internet of things devices, and in low-cost advertising applications. While inorganics have so far dominated the market, organic conductive polymers possess certain advantages such as high throughput and low temperature processing, faster switching, and superior optical memory. Here, we present organic electrochromic devices that can switch between two high-resolution images, based on UV-patterning and vapor phase polymerization of poly(3,4-ethylenedioxythiophene) films. We demonstrate that this technique can provide switchable greyscale images through the spatial control of a UV-light dose. The color space was able to be further altered via optimization of the oxidant concentration. Finally, we utilized a UV-patterning technique to produce functional paper with electrochromic patterns deposited on porous paper, allowing for environmentally friendly electrochromic displays.

scholarly journals Luminescent Electrochromic Devices for Smart Windows of Energy-Efficient Buildings

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3513 ◽  
Author(s):  
Mariana Fernandes ◽  
Vânia Freitas ◽  
Sónia Pereira ◽  
Rita Leones ◽  
Maria Silva ◽  
...  
Keyword(s):  
Energy Efficient ◽  
Near Infrared ◽  
Sol Gel ◽  
Average Molecular Weight ◽  
The Novel ◽  
Electrochromic Devices ◽  
Lithium Triflate ◽  
Smart Windows ◽  
Energy Efficient Buildings ◽  
Nir Emission

To address the challenges of the next generation of smart windows for energy-efficient buildings, new electrochromic devices (ECDs) are introduced. These include indium molybdenum oxide (IMO), a conducting oxide transparent in the near-infrared (NIR) region, and a NIR-emitting electrolyte. The novel electrolytes are based on a sol-gel-derived di-urethane cross-linked siloxane-based host structure, including short chains of poly (ε-caprolactone) (PCL(530) (where 530 represents the average molecular weight in g mol−1). This hybrid framework was doped with a combination of either, lithium triflate (LiTrif) and erbium triflate (ErTrif3), or LiTrif and bisaquatris (thenoyltrifluoroacetonate) erbium (III) ([Er(tta)3(H2O)2]). The ECD@LiTrif-[Er(tta)3(H2O)2] device presents a typical Er3+ NIR emission around 1550 nm. The figures of merit of these devices are high cycling stability, good reversibility, and unusually high coloration efficiency (CE = ΔOD/ΔQ, where Q is the inserted/de-inserted charge density). CE values of −8824/+6569 cm2 C−1 and −8243/+5200 cm2 C−1 were achieved at 555 nm on the 400th cycle, for ECD@LiTrif-ErTrif3 and ECD@LiTrif-[Er(tta)3(H2O)2], respectively.

scholarly journals Lifetime of electrochromic optical transition cycling of ethyl viologen diperchlorate-based electrochromic devices

2021 ◽  
Vol 3 (5) ◽  
Author(s):  
Logan G. Kiefer ◽  
Christian J. Robert ◽  
Taylor D. Sparks
Keyword(s):  
Optical Transition ◽  
Low Cost ◽  
Cycling Performance ◽  
Power Measurement ◽  
Electrochromic Devices ◽  
Metal Oxide Films ◽  
Cycle Times ◽  
Vis Spectroscopy ◽  
Multiple Devices ◽  
Measurement Devices

AbstractElectrochromic materials and devices are enabling a variety of advanced technologies. Gel-based organic electrochromic molecules such as ethyl viologen diperchlorate are attractive options due to their simple device design and low cost processing options relative to the more expensive and complex transition metal oxide films. However, electrochromic devices are subject to extensive cycling in which failure and fatigue can eventually occur. This work presents the lifetime cycling performance of ethyl viologen diperchlorate-based electrochromic devices using two different anodic compounds, hydroquinone and ferrocene, which are cycled at different voltages, 3 V and 1.2 V, respectively. Multiple devices are cycled until failure with periodic device characterization via UV–Vis spectroscopy, electrical resistance and power measurement, and transition duration measurement. Devices with hydroquinone can transition quickly. Cycle times are $$\sim$$ ∼ 30 s in these samples, however, these samples also typically fail before 3000 cycles. On the other hand, devices using ferrocene transition more slowly (total cycle time $$\sim$$ ∼ 2 min), but have superior cycling performance with all samples surviving beyond 10,000 cycles while complying with ASTM E2141-14 standard.

Synthesis, Properties and Application in Optical Memory of a New Photochromic Diarylethene Based on a Chlorine Atom

2012 ◽  
Vol 455-456 ◽  
pp. 25-28 ◽  
Author(s):  
Zhi Peng Tong ◽  
Gang Liu ◽  
Shi Qiang Cui
Keyword(s):  
Chlorine Atom ◽  
Uv Light ◽  
Optical Memory ◽  
Optical Recording ◽  
Pmma Film ◽  
Recording Medium ◽  
Photochromic Properties ◽  
Synthesis Properties

A new unsymmetrical photochromic diarylethene 1-(2,4-dimethyl-3-isoxazol)-2-[2-methyl-5-(2-chlorophenyl) -3-thienyl] perfluorocyclopentene (1a) has been synthesized. Its photochromic properties in solution and PMMA film were investigated. Diarylethene 1a changed the color from colorless to red upon irradiation with 297 nm UV light, in which absorption maxima were observed at 515 nm in hexane and at 526 nm in PMMA film, The results demonstrated that it can be potentially used as polarization holographic optical recording medium.

scholarly journals Low cost, multiscale and multi-sensor application for flooded areas mapping

2017 ◽  
Author(s):  
Daniele Giordan ◽  
Davide Notti ◽  
Alfredo Villa ◽  
Francesco Zucca ◽  
Fabiana Calò ◽  
...  
Keyword(s):  
High Resolution ◽  
Low Cost ◽  
Essential Elements ◽  
Basin Scale ◽  
High Resolution Images ◽  
Maximum Water ◽  
Urbanized Areas ◽  
Flooded Area ◽  
Elevation Model ◽  
Flooded Areas

Abstract. Flood mapping and estimation of maximum water depth are essential elements for a first damages evaluation, civil protection interventions planning and detection of areas where remedial are more needed. In this work, we present and discuss a methodology for mapping and quantifying flood severity over plain areas. The proposed methodology considers a multiscale and multi-sensor approach using free or low-cost data/sensors. We applied this method to November 2016 Piemonte (NW Italy) flood. We first mapped flooded areas at basin scale using free satellite data from low to medium-high resolution using both SAR (Sentinel-1, Cosmo-Skymed) and multispectral sensors (MODIS, Sentinel-2). Using very- and ultra- high-resolution images from the low-cost aerial platform and Remotely Piloted Aerial System, we refined the flooded zone, and we detected the most damaged sector. The presented method considers both urbanized and not urbanized areas. Nadiral images have several limitations in particular in urbanized areas, where the use of terrestrial images solved this limitation. Very- and ultra-high resolution images have been processed with Structure from Motion (SfM) for the realization of 3-D models. These data, combined with available digital elevation model, allowed us to obtain maps of flooded area, maximum water high and damaged infrastructures.

A Very Low-Cost, Labor-Efficient, and Simple Method to Block Scattered Ultraviolet Light in PDMS Microfluidic Devices by Inserting Aluminum Foil Strips

2018 ◽  
Vol 11 (1) ◽  
Author(s):  
Shuo Wang ◽  
Peter Shankles ◽  
Scott Retterer ◽  
Yong Tae Kang ◽  
Chang Kyoung Choi
Keyword(s):  
Soft Lithography ◽  
Uv Light ◽  
Low Cost ◽  
Microfluidic Devices ◽  
Aluminum Foil ◽  
Material Synthesis ◽  
Simple Method ◽  
Micro Particles ◽  
Complex Shapes ◽  
The Cost

Abstract Opto-microfluidic methods have advantages for manufacturing complex shapes or structures of micro particles/hydrogels. Most of these microfluidic devices are made of polydimethylsiloxane (PDMS) by soft lithography because of its flexibility of designing and manufacturing. However, PDMS scatters ultraviolet (UV) light, which polymerizes the photocrosslinkable materials at undesirable locations and clogs the microfluidic devices. A fluorescent dye has previously been employed to absorb the scattered UV light and shift its wavelength to effectively solve this issue. However, this method is limited due to the cost of the materials (tens of dollars per microchip), the time consumed on synthesizing the fluorescent material and verifying its quality (two to three days). More importantly, significant expertise on material synthesis and characterization is required for users of the opto-microfluidic technique. The cost of preliminary testing on multiple iterations of different microfluidic chip designs would also be excessive. Alternatively, with a delicate microchannel design, we simply inserted aluminum foil strips (AFS) inside the PDMS device to block the scattered UV light. By using this method, the UV light was limited to the exposure region so that the opto-microfluidic device could consistently generate microgels longer than 6 h. This is a nearly cost- and labor-free method to solve this issue.

Sol-gel-derived gallium nitride thin films for ultraviolet photodetection

2019 ◽  
Vol 36 (1) ◽  
pp. 8-13 ◽  
Author(s):  
Chee Yong Fong ◽  
Sha Shiong Ng ◽  
NurFahana Mohd Amin ◽  
Fong Kwong Yam ◽  
Zainuriah Hassan
Keyword(s):  
Thin Films ◽  
Dark Current ◽  
Uv Light ◽  
Low Cost ◽  
Sol Gel ◽  
Contrast Ratio ◽  
Uv Photodetector ◽  
Content Type ◽  
Barrier Heights ◽  
Coating Method

Purpose This study aims to explore the applicability of the sol-gel-derived GaN thin films for UV photodetection. Design/methodology/approach GaN-based ultraviolet (UV) photodetector with Pt Schottky contacts was fabricated and its applicability was investigated. The current-voltage (I-V) characteristics of the GaN-based UV photodetector under the dark current and photocurrent were measured. Findings The ideality factors of GaN-based UV photodetector under dark current and photocurrent were 6.93 and 5.62, respectively. While the Schottky barrier heights (SBH) for GaN-based UV photodetector under dark current and photocurrent were 0.35 eV and 0.34 eV, respectively. The contrast ratio and responsivity of this UV photodetector measured at 5 V were found to be 1.36 and 1.68 μA/W, respectively. The photoresponse as a function of time was measured by switching the UV light on and off continuously at different forward biases of 1, 3 and 6 V. The results showed that the fabricated UV photodetector has reasonable stability and repeatability. Originality/value This work demonstrated that GaN-based UV photodetector can be fabricated by using the GaN thin film grown by low-cost and simple sol-gel spin coating method.

A low cost preparation of WO3 nanospheres film with improved thermal stability of gasochromic and its application in smart windows

2017 ◽  
Vol 4 (11) ◽  
pp. 115702 ◽  
Author(s):  
Baoyu Zhou ◽  
Wei Feng ◽  
Guohua Gao ◽  
Guangming Wu ◽  
Yue Chen ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Low Cost ◽  
Smart Windows ◽  
Thermal Stability Of

scholarly journals 207-nm UV Light - A Promising Tool for Safe Low-Cost Reduction of Surgical Site Infections. I: In Vitro Studies

PLoS ONE ◽  
2013 ◽  
Vol 8 (10) ◽  
pp. e76968 ◽  
Author(s):  
Manuela Buonanno ◽  
Gerhard Randers-Pehrson ◽  
Alan W. Bigelow ◽  
Sheetal Trivedi ◽  
Franklin D. Lowy ◽  
...  
Keyword(s):  
Cost Reduction ◽  
Uv Light ◽  
Low Cost ◽  
Surgical Site Infections ◽  
In Vitro Studies ◽  
Promising Tool

scholarly journals UNMANNED AERIAL VEHICLE APPLICATIONS OF 3D MODELLING, VISUALIZATION AND PARAMETER CALCULATIONS

2018 ◽  
Vol XLII-5 ◽  
pp. 649-652 ◽  
Author(s):  
V. Lambey ◽  
A. D. Prasad
Keyword(s):  
Point Cloud ◽  
Low Cost ◽  
3D Modelling ◽  
Aerial Photogrammetry ◽  
Average Accuracy ◽  
Aerial Vehicle ◽  
High Resolution Images ◽  
Institute Of Technology ◽  
Uav Images ◽  
Economical Alternative

<p><strong>Abstract.</strong> Photogrammetric surveying with the use of Unmanned Aerial Vehicles (UAV) have gained vast popularity in short span. UAV have the potential to provide imagery at an extraordinary spatial and temporal resolution when coupled with remote sensing. Currently, UAV platforms are fastest and easiest source of data for mapping and 3D modelling. It is to be considered as a low-cost substitute to the traditional airborne photogrammetry. In the present study, UAV applications are explored in terms of 3D modelling, visualization and parameter calculations. National Institute of Technology Raipur, Raipur is chosen as study area and high resolution images are acquired from the UAV with 85% overlap. 3D model is processed through the point cloud generated for the UAV images. The results are compared with traditional methods for validation. The average accuracy obtained for elevation points and area is 97.99% and 97.75%. The study proves that UAV based surveying is an economical alternative in terms of money, time and resources, when compared to the classical aerial photogrammetry methods.</p>

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