scholarly journals Demonstration of thermal modulation using nanoscale and microscale structures for ultralarge pixel array photothermal transducers

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Jinying Zhang ◽  
Defang Li ◽  
Zhuo Li ◽  
Xin Wang ◽  
Suhui Yang
Keyword(s):  
Temperature Difference ◽  
Infrared Imaging ◽  
Wide Spectrum ◽  
Low Cost ◽  
Fold Increase ◽  
Fast Time ◽  
Thermal Modulation ◽  
Nanoscale Structures ◽  
Pixel Array ◽  
Black Coating

AbstractLarge-pixel-array infrared emitters are attractive in the applications of infrared imaging and detection. However, the array scale has been restricted in traditional technologies. Here, we demonstrated a light-driven photothermal transduction approach for an ultralarge pixel array infrared emitter. A metal-black coating with nanoporous structures and a silicon (Si) layer with microgap structures were proposed to manage the thermal input and output issues. The effects of the nanoscale structures in the black coating and microscale structures in the Si layer were investigated. Remarkable thermal modulation could be obtained by adjusting the nanoscale and microscale structures. The measured stationary and transient results of the fabricated photothermal transducers agreed well with the simulated results. From the input view, due to its wide spectrum and high absorption, the black coating with nanoscale structures contributed to a 5.6-fold increase in the temperature difference compared to that without the black coating. From the output view, the microgap structures in the Si layer eliminated the in-plane thermal crosstalk. The temperature difference was increased by 340% by modulating the out-of-plane microstructures. The proposed photothermal transducer had a rising time of 0.95 ms and a falling time of 0.53 ms, ensuring a fast time response. This method is compatible with low-cost and mass manufacturing and has promising potential to achieve ultralarge-array pixels beyond ten million.

scholarly journals Ga-La-S-Se glass for visible and thermal imaging

2017 ◽  
Vol 6 (2) ◽  
Author(s):  
Andrea Ravagli ◽  
Christopher Craig ◽  
John Lincoln ◽  
Daniel W. Hewak
Keyword(s):  
Thermal Imaging ◽  
Chalcogenide Glasses ◽  
Infrared Imaging ◽  
Low Cost ◽  
Short Wave ◽  
Infrared Transmission ◽  
New Family ◽  
Near Net Shape ◽  
Se Glass ◽  
Long Wave Infrared

AbstractChalcogenide glasses are emerging as important enabling materials for low-cost infrared imaging by virtue of their transparency in the key short-wave infrared (SWIR) to long-wave infrared (LWIR) bands and the ability to be mass produced and molded into near-net shape lenses. In this paper, we introduce a new family of chalcogenide glasses, which offer visible as well as infrared transmission and improved thermal and mechanical properties. These glasses are based on Ga

Advances in low-cost infrared imaging using II-VI colloidal quantum dots (Conference Presentation)

2017 ◽  
Author(s):  
Richard E. Pimpinella ◽  
Christopher Buurma ◽  
Anthony J. Ciani ◽  
Christoph H. Grein ◽  
Philippe Guyot-Sionnest
Keyword(s):  
Quantum Dots ◽  
Infrared Imaging ◽  
Low Cost ◽  
Colloidal Quantum Dots

scholarly journals Distributed Base Station: A Concept System for Long-Range Broadband Wireless Access

Electronics ◽  
2021 ◽  
Vol 10 (19) ◽  
pp. 2396
Author(s):  
Muhammed Faruk Gencel ◽  
Maryam Eslami Rasekh ◽  
Upamanyu Madhow
Keyword(s):  
Low Cost ◽  
Fold Increase ◽  
Adaptation Strategy ◽  
Base Station ◽  
Range Extension ◽  
Transmit Beamforming ◽  
Broadband Wireless ◽  
Concept System ◽  
Received Power ◽  
Rural Broadband

We propose a concept system termed distributed base station (DBS) which enables distributed transmit beamforming at large carrier wavelengths to achieve significant range extension and/or increased downlink data rate, providing a low-cost infrastructure for applications such as rural broadband. We consider a frequency division duplexed (FDD) system using feedback from the receiver to achieve the required phase coherence. At a given range, N cooperating transmitters can achieve N2-fold increase in received power compared to that for a single transmitters, and feedback-based algorithms with near-ideal performance have been prototyped. In this paper, however, we identify and address key technical issues in translating such power gains into range extension via a DBS. First, to combat the drop in per-node SNR with extended range, we design a feedback-based adaptation strategy that is suitably robust to noise. Second, to utilize available system bandwidth, we extend narrowband adaptation algorithms to wideband channels through interpolation over OFDM subcarriers. Third, we observe that the feedback channel may become a bottleneck unless sophisticated distributed reception strategies are employed, but show that acceptable performance can still be obtained with standard uplink reception if channel time variations are slow enough. We quantify system performance compactly via outage capacity analyses.

scholarly journals A Novel Approach of Parallel Retina-Like Computational Ghost Imaging

Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7093
Author(s):  
Jie Cao ◽  
Dong Zhou ◽  
Fanghua Zhang ◽  
Huan Cui ◽  
Yingqiang Zhang ◽  
...  
Keyword(s):  
Wide Spectrum ◽  
Low Cost ◽  
Parallel Architecture ◽  
Structure Design ◽  
Ghost Imaging ◽  
Novel Approach ◽  
Time Correlations ◽  
Long Time ◽  
Sampling And Reconstruction ◽  
Similar Imaging

Computational ghost imaging (CGI), with the advantages of wide spectrum, low cost, and robustness to light scattering, has been widely used in many applications. The key issue is long time correlations for acceptable imaging quality. To overcome the issue, we propose parallel retina-like computational ghost imaging (PRGI) method to improve the performance of CGI. In the PRGI scheme, sampling and reconstruction are carried out by using the patterns which are divided into blocks from designed retina-like patterns. Then, the reconstructed image of each block is stitched into the entire image corresponding to the object. The simulations demonstrate that the proposed PRGI method can obtain a sharper image while greatly reducing the time cost than CGI based on compressive sensing (CSGI), parallel architecture (PGI), and retina-like structure (RGI), thereby improving the performance of CGI. The proposed method with reasonable structure design and variable selection may lead to improve performance for similar imaging methods and provide a novel technique for real-time imaging applications.

scholarly journals Geometric Prepatterning-Based Tuning of the Period Doubling Onset Strain During Thin-Film Wrinkling

2017 ◽  
Vol 84 (5) ◽  
Author(s):  
Sourabh K. Saha
Keyword(s):  
Low Cost ◽  
Period Doubling ◽  
Delay Period ◽  
Natural Period ◽  
Nanoscale Structures ◽  
Formation Behavior ◽  
Sinusoidal Pattern ◽  
System Knowledge ◽  
Practical Scheme ◽  
Nonlinear Pattern

Wrinkling of thin films is an easy-to-implement and low-cost technique to fabricate stretch-tunable periodic micro and nanoscale structures. However, the tunability of such structures is often limited by the emergence of an undesirable period-doubled mode at high strains. Predictively tuning the onset strain for period doubling via existing techniques requires one to have extensive knowledge about the nonlinear pattern formation behavior. Herein, a geometric prepatterning-based technique is introduced that can be implemented even with limited system knowledge to predictively delay period doubling. The technique comprises prepatterning the film/base bilayer with a sinusoidal pattern that has the same period as the natural period of the system. This technique has been verified via physical and computational experiments on the polydimethylsiloxane (PDMS)/glass bilayer system. It is observed that the onset strain can be increased from the typical value of 20% for flat films to greater than 30% with a modest prepattern aspect ratio (2·amplitude/period) of 0.15. In addition, finite element simulations reveal that (i) the onset strain increases with increasing prepattern amplitude and (ii) the delaying effect can be captured entirely by the prepattern geometry. Therefore, one can implement this technique even with limited system knowledge, such as material properties or film thickness, by simply replicating pre-existing wrinkled patterns to generate prepatterned bilayers. Thus, geometric prepatterning is a practical scheme to increase the operating range of stretch-tunable wrinkle-based devices by at least 50%.

Detection of Crack Growth in Asphalt Pavement Through Use of Infrared Imaging

2017 ◽  
Vol 2645 (1) ◽  
pp. 24-31 ◽  
Author(s):  
Yuchuan Du ◽  
Xiaoming Zhang ◽  
Feng Li ◽  
Lijun Sun
Keyword(s):  
Crack Growth ◽  
Temperature Difference ◽  
Crack Detection ◽  
Infrared Imaging ◽  
Asphalt Pavement ◽  
Atmospheric Temperature ◽  
Support Vector ◽  
Road Maintenance ◽  
Pavement Maintenance ◽  
Detection Model

The degree of crack growth in asphalt pavement is an important decision-making factor in road maintenance management. Automatic crack detection is based mainly on digital images; this factor makes effective detection of the degree of crack growth difficult. Infrared thermography was used, and a detection method for the degree of crack growth on the basis of infrared imaging was proposed. Infrared images included gray-level information on cracks and temperature information; the latter provided one additional dimension of information over ordinary images. Temperature information was used to detect the degree of crack growth. Atmospheric temperature was found to be the main factor that affected the temperature difference between a crack and the road surface. This temperature difference varied significantly for different extents of crack growth, and therefore this difference can be used to detect the degree of crack growth. Two classification functions that divided the degree of crack growth into three grades were obtained by classifying data through the use of a support vector machine. A suitable environmental condition for using the detection model was proposed. The experimental results showed that the average model error was 15.4%, which indicated a good application prospect and an improvement in economic benefit for pavement maintenance.

scholarly journals Three-Dimensional Thermal Mapping from IRT Images for Rapid Architectural Heritage NDT

Buildings ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 187
Author(s):  
Efstathios Adamopoulos ◽  
Monica Volinia ◽  
Mario Girotto ◽  
Fulvio Rinaudo
Keyword(s):  
Optical Sensors ◽  
Infrared Imaging ◽  
Low Cost ◽  
Three Dimensional ◽  
Cost Effective ◽  
Thermal Infrared ◽  
Architectural Heritage ◽  
Thermal Camera ◽  
Historical Building ◽  
Custom Made

Thermal infrared imaging is fundamental to architectural heritage non-destructive diagnostics. However, thermal sensors’ low spatial resolution allows capturing only very localized phenomena. At the same time, thermal images are commonly collected with independence of geometry, meaning that no measurements can be performed on them. Occasionally, these issues have been solved with various approaches integrating multi-sensor instrumentation, resulting in high costs and computational times. The presented work aims at tackling these problems by proposing a workflow for cost-effective three-dimensional thermographic modeling using a thermal camera and a consumer-grade RGB camera. The discussed approach exploits the RGB spectrum images captured with the optical sensor of the thermal camera and image-based multi-view stereo techniques to reconstruct architectural features’ geometry. The thermal and optical sensors are calibrated employing custom-made low-cost targets. Subsequently, the necessary geometric transformations between undistorted thermal infrared and optical images are calculated to replace them in the photogrammetric scene and map the models with thermal texture. The method’s metric accuracy is evaluated by conducting comparisons with different sensors and the efficiency by assessing how the results can assist the better interpretation of the present thermal phenomena. The conducted application demonstrates the metric and radiometric performance of the proposed approach and the straightforward implementability for thermographic surveys, as well as its usefulness for cost-effective historical building assessments.

scholarly journals Seed Pretreatment for Increased Hydrogen Production Using Mixed-Culture Systems with Advantages over Pure-Culture Systems

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 530 ◽  
Author(s):  
Vinayak Laxman Pachapur ◽  
Prianka Kutty ◽  
Preetika Pachapur ◽  
Satinder Kaur Brar ◽  
Yann Le Bihan ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Mixed Culture ◽  
Pure Culture ◽  
Wide Spectrum ◽  
Low Cost ◽  
Production Costs ◽  
Microbial Consortia ◽  
Culture Systems ◽  
Seed Pretreatment ◽  
Media Supplements

Hydrogen is an important source of energy and is considered as the future energy carrier post-petroleum era. Nowadays hydrogen production through various methods is being explored and developed to minimize the production costs. Biological hydrogen production has remained an attractive option, highly economical despite low yields. The mixed-culture systems use undefined microbial consortia unlike pure-cultures that use defined microbial species for hydrogen production. This review summarizes mixed-culture system pretreatments such as heat, chemical (acid, alkali), microwave, ultrasound, aeration, and electric current, amongst others, and their combinations to improve the hydrogen yields. The literature representation of pretreatments in mixed-culture systems is as follows: 45–50% heat-treatment, 15–20% chemical, 5–10% microwave, 10–15% combined and 10–15% other treatment. In comparison to pure-culture mixed-culture offers several advantages, such as technical feasibility, minimum inoculum steps, minimum media supplements, ease of operation, and the fact it works on a wide spectrum of low-cost easily available organic wastes for valorization in hydrogen production. In comparison to pure-culture, mixed-culture can eliminate media sterilization (4 h), incubation step (18–36 h), media supplements cost ($4–6 for bioconversion of 1 kg crude glycerol (CG)) and around 10–15 Millijoule (MJ) of energy can be decreased for the single run.

Transparent Conducting Oxides for Photovoltaics

MRS Bulletin ◽  
2007 ◽  
Vol 32 (3) ◽  
pp. 242-247 ◽  
Author(s):  
Elvira Fortunato ◽  
David Ginley ◽  
Hideo Hosono ◽  
David C. Paine
Keyword(s):  
Wide Spectrum ◽  
Polymer Solar Cells ◽  
Low Cost ◽  
Transparent Conducting Oxides ◽  
Open Circuit ◽  
Flat Panel Display ◽  
Conducting Oxides ◽  
Transparent Conducting ◽  
The Matrix ◽  
Organic Pv

AbstractTransparent conducting oxides (TCOs) are an increasingly important component of photovoltaic (PV) devices, where they act as electrode elements, structural templates, and diffusion barriers, and their work function controls the open-circuit device voltage. They are employed in applications that range from crystalline-Si heterojunction with intrinsic thin layer (HIT) cells to organic PV polymer solar cells. The desirable characteristics of TCO materials that are common to all PV technologies are similar to the requirements for TCOs for flat-panel display applications and include high optical transmissivity across a wide spectrum and low resistivity. Additionally, TCOs for terrestrial PV applications must use low-cost materials, and some may require device-technology-specific properties. We review the fundamentals of TCOs and the matrix of TCO properties and processing as they apply to current and future PV technologies.

Systematic Study of Ge0.89Sn0.11 Photodiodes for Low-Cost Shortwave Infrared Imaging

2018 ◽  
Author(s):  
Huong Tran ◽  
Thach Pham ◽  
Wei Du ◽  
Yang Zhang ◽  
Seyed Amir Ghetmiri ◽  
...  
Keyword(s):  
Systematic Study ◽  
Infrared Imaging ◽  
Low Cost ◽  
Shortwave Infrared
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