Construction of Polymer Materials with Specific Responses to Violet and Green Lights and Their Potential Applications in Artificial Visual Memory System

2022 ◽  
Author(s):  
Guan Wang ◽  
Hua Li ◽  
Qijian Zhang ◽  
Fengjuan Zhu ◽  
Junwei Yuan ◽  
...  
Keyword(s):  
Visible Light ◽  
Visual Memory ◽  
Memory System ◽  
Polymer Materials ◽  
Electrical Signals ◽  
Potential Applications ◽  
Light Signals ◽  
And Robotics

Artificial retinal materials play an important role in vision repair and robotics. However, the inability to convert characteristic visible light signals into electrical signals has seriously hindered the development and...

scholarly journals Physical Properties of Thermoplastic Starch Derived from Natural Resources and Its Blends: A Review

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1396
Author(s):  
Z. N. Diyana ◽  
R. Jumaidin ◽  
Mohd Zulkefli Selamat ◽  
Ihwan Ghazali ◽  
Norliza Julmohammad ◽  
...  
Keyword(s):  
Thermoplastic Starch ◽  
Natural Fibre ◽  
Polymer Materials ◽  
Secondary Pollution ◽  
Wide Range ◽  
Potential Applications ◽  
Long Time ◽  
To Come ◽  
Main Component ◽  
Significant Attention

Thermoplastic starch composites have attracted significant attention due to the rise of environmental pollutions induced by the use of synthetic petroleum-based polymer materials. The degradation of traditional plastics requires an unusually long time, which may lead to high cost and secondary pollution. To solve these difficulties, more petroleum-based plastics should be substituted with sustainable bio-based plastics. Renewable and natural materials that are abundant in nature are potential candidates for a wide range of polymers, which can be used to replace their synthetic counterparts. This paper focuses on some aspects of biopolymers and their classes, providing a description of starch as a main component of biopolymers, composites, and potential applications of thermoplastics starch-based in packaging application. Currently, biopolymer composites blended with other components have exhibited several enhanced qualities. The same behavior is also observed when natural fibre is incorporated with biopolymers. However, it should be noted that the degree of compatibility between starch and other biopolymers extensively varies depending on the specific biopolymer. Although their efficacy is yet to reach the level of their fossil fuel counterparts, biopolymers have made a distinguishing mark, which will continue to inspire the creation of novel substances for many years to come.

Light-Driven Integration of Graphitic Carbon Nitride into Polymer Materials

2021 ◽  
Vol 7 (1) ◽  
pp. 9
Author(s):  
Cansu Esen ◽  
Baris Kumru
Keyword(s):  
Visible Light ◽  
Carbon Nitride ◽  
Dye Degradation ◽  
Polymer Networks ◽  
Co2 Reduction ◽  
Polymeric Materials ◽  
Polymer Materials ◽  
Visible Range ◽  
Light Illumination ◽  
Present Contribution

As a metal-free polymeric semiconductor with an absorption in the visible range, carbon nitride has numerous advantages for photo-based applications spanning hydrogen evolution, CO2 reduction, ion transport, organic synthesis and organic dye degradation. The combination of g-C3N4 and polymer networks grants mutual benefit for both platforms, as networks are upgraded with photoactivity or formed by photoinitiation, and g-C3N4 is integrated into novel applications. In the present contribution, some of the recently published projects regarding g-C3N4 and polymeric materials will be highlighted. In the first study, organodispersible g-C3N4 were incorporated into a highly commercialized porous resin called poly(styrene-co-divinylbenzene) through suspension photopolymerization, and performances of resulting beads were investigated as recyclable photocatalysts. In the other study, g-C3N4 nanosheets were embedded in porous hydrogel networks, and so-formed hydrogels with photoactivity were transformed either into a ‘hydrophobic hydrogel’ or pore-patched materials via secondary network introduction, where both processes were accomplished via visible light. Since g-C3N4 is an organic semiconductor exhibiting sufficient charge separation under visible light illumination, a novel method for the oxidative photopolymerization of EDOT was successfully accomplished. As a result of the absence of dissolved anions during polymerization, so-formed neutral PEDOT is a highly viscous liquid that can be processed and post-doped easily, and grants facile coating processes.

scholarly journals Quad-Band Plasmonic Perfect Absorber for Visible Light with a Patchwork of Silicon Nanorod Resonators

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1954 ◽  
Author(s):  
Can Cao ◽  
Yongzhi Cheng
Keyword(s):  
Visible Light ◽  
Transverse Electric ◽  
Transverse Magnetic ◽  
Localized Surface Plasmon ◽  
Perfect Absorber ◽  
Absorption Properties ◽  
Perfect Absorption ◽  
Potential Applications ◽  
Polarization Insensitive ◽  
Band Absorption

In this paper, a plasmonic perfect absorber (PPA) based on a silicon nanorod resonator (SNRR) for visible light is proposed and investigated numerically. The proposed PPA is only a two-layer nanostructure consisting of a SNRR periodic array and metal substrate. The perfect absorption mainly originates from excitation of the localized surface plasmon resonance (LSPR) mode in the SNRR structure. The absorption properties of this design can be adjusted by varying the radius (r) and height (h) of the SNRR structure. What is more, the stronger quad-band absorption can be achieved by combing four different radius of the SNRR in one period as a super unit-cell. Numerical simulation indicates that the designed quad-band PPA can achieve the absorbance of 99.99%, 99.8%, 99.8%, and 92.2% at 433.5 THz, 456 THz, 482 THz, and 504.5 THz, respectively. Further simulations show that the proposed PPA is polarization-insensitive for both transverse electric (TE) and transverse magnetic (TM) modes. The proposed PPA can be a desirable candidate for some potential applications in detecting, sensing, and visible spectroscopy.

scholarly journals Visible-Light Photoswitching of G-Quadruplex Ligand Binding Mode Allows Reversible Control of G-Tetrad Structure

2020 ◽  
Author(s):  
Michael O'Hagan ◽  
Javier Ramos Soriano ◽  
Susanta Haldar ◽  
Juan Carlos Morales ◽  
Adrian Mulholland ◽  
...  
Keyword(s):  
Ligand Binding ◽  
Visible Light ◽  
Uv Light ◽  
Binding Mode ◽  
High Energy ◽  
Light Sources ◽  
Biologically Relevant ◽  
G Quadruplex ◽  
Potential Applications ◽  
Robust Regulation

<div><p>Photoresponsive ligands for G-quadruplex oligonucleotides (G4) offer exciting opportunities for the reversible regulation of these assemblies with potential applications in biological chemistry and responsive nanotechnology. However, achieving the robust regulation of G4 ligand activity with low-energy visible light sources that are easily accessible and compatible with biological systems remains a significant challenge to realizing these applications. Herein, we report the G4-binding properties of a photoresponsive dithienylethene (DTE). We demonstrate the first example of G4-specific acceleration of the photoswitching kinetics of a small molecule and the visible-light mediated switching of the G4 ligand binding mode in physiologically-relevant conditions, which in turn allows control over the G4 tetrad structure of telomeric G4 in potassium buffer. The process is fully reversible and avoids the need for high-energy UV light. This affords an efficient, practical and biologically-relevant means of control that may be applied in the generation of new responsive G4/ligand supramolecular systems.</p></div><br>

scholarly journals Human Gaze Assisted Artificial Intelligence: A Review

2020 ◽  
Author(s):  
Ruohan Zhang ◽  
Akanksha Saran ◽  
Bo Liu ◽  
Yifeng Zhu ◽  
Sihang Guo ◽  
...  
Keyword(s):  
Artificial Intelligence ◽  
Language Processing ◽  
Cognitive State ◽  
Data Sets ◽  
Common Goal ◽  
Research Areas ◽  
Future Challenges ◽  
Potential Applications ◽  
High Level ◽  
And Robotics

Human gaze reveals a wealth of information about internal cognitive state. Thus, gaze-related research has significantly increased in computer vision, natural language processing, decision learning, and robotics in recent years. We provide a high-level overview of the research efforts in these fields, including collecting human gaze data sets, modeling gaze behaviors, and utilizing gaze information in various applications, with the goal of enhancing communication between these research areas. We discuss future challenges and potential applications that work towards a common goal of human-centered artificial intelligence.

scholarly journals Enhanced Antibacterial Activity of Silver Doped Titanium Dioxide-Chitosan Composites under Visible Light

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1403 ◽  
Author(s):  
Jie Li ◽  
Bing Xie ◽  
Kai Xia ◽  
Yingchun Li ◽  
Jing Han ◽  
...  
Keyword(s):  
Particle Size ◽  
Antibacterial Activity ◽  
Titanium Dioxide ◽  
Visible Light ◽  
Silver Ions ◽  
Antibacterial Activities ◽  
Nano Tio2 ◽  
Inverse Emulsion ◽  
Potential Applications

Nano titanium dioxide (TiO2) with photocatalytic activity was firstly modified by diethanolamine, and it was then doped with broad spectrum antibacterial silver (Ag) by in situ method. Further, both Ag doped TiO2-chitosan (STC) and TiO2-chitosan (TC) composites were prepared by the inverse emulsion cross-linking reaction. The antibacterial activities of STC composites were studied and their antibacterial mechanisms under visible light were investigated. The results show that in situ doping and inverse emulsion method led to good dispersion of Ag and TiO2 nanoparticles on the cross-linked chitosan microsphere. The STC with regular particle size of 1–10 μm exhibited excellent antibacterial activity against E. coli, P. aeruginosa and S. aureus under visible light. It is believed that STC with particle size of 1–10 μm has large specific surface area to contact with bacterial cell wall. The increased antibacterial activity was attributed to the enhancement of both electron-hole separations at the surface of nano-TiO2 by the silver ions under the visible light, and the synergetic and sustained release of strong oxidizing hydroxyl radicals of nano-TiO2, together with silver ions against bacteria. Thus, STC composites have great potential applications as antibacterial agents in the water treatment field.

Quasiperiodic-Chaotic Neural Networks and Short-Term Analog Memory

2021 ◽  
Vol 31 (01) ◽  
pp. 2130003
Author(s):  
Natsuhiro Ichinose
Keyword(s):  
Neural Networks ◽  
Visual Memory ◽  
Large Scale ◽  
Quasiperiodic Solution ◽  
Short Term ◽  
Chaotic Neural Networks ◽  
Analog Memory ◽  
Short Term Visual Memory ◽  
Potential Applications ◽  
Chaotic Neuron

A model of quasiperiodic-chaotic neural networks is proposed on the basis of chaotic neural networks. A quasiperiodic-chaotic neuron exhibits quasiperiodic dynamics that an original chaotic neuron does not have. Quasiperiodic and chaotic solutions are exclusively isolated in the parameter space. The chaotic domain can be identified by the presence of a folding structure of an invariant closed curve. Using the property that the influence of perturbation is conserved in the quasiperiodic solution, we demonstrate short-term visual memory in which real numbers are acceptable for representing colors. The quasiperiodic solution is sensitive to dynamical noise when images are restored. However, the quasiperiodic synchronization among neurons can reduce the influence of noise. Short-term analog memory using quasiperiodicity is important in that it can directly store analog quantities. The quasiperiodic-chaotic neural networks are shown to work as large-scale analog storage arrays. This type of analog memory has potential applications to analog computation such as deep learning.

scholarly journals Preparation of Succinoglycan Hydrogel Coordinated With Fe3+ Ions for Controlled Drug Delivery

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 977 ◽  
Author(s):  
Yiluo Hu ◽  
Daham Jeong ◽  
Yohan Kim ◽  
Seonmok Kim ◽  
Seunho Jung
Keyword(s):  
Drug Delivery ◽  
Visible Light ◽  
Sinorhizobium Meliloti ◽  
Environmental Changes ◽  
Controlled Drug Delivery ◽  
Attenuated Total Reflection ◽  
Extracellular Polysaccharides ◽  
Rheological Analysis ◽  
Wide Range ◽  
Potential Applications

Hydrogel materials with a gel-sol conversion due to external environmental changes have potential applications in a wide range of fields, including controlled drug delivery. Succinoglycans are anionic extracellular polysaccharides produced by various bacteria, including Sinorhizobium species, which have diverse applications. In this study, the rheological analysis confirmed that succinoglycan produced by Sinorhizobium meliloti Rm 1021 binds weakly to various metal ions, including Fe2+ cations, to maintain a sol form, and binds strongly to Fe3+ cations to maintain a gel form. The Fe3+-coordinated succinoglycan (Fe3+-SG) hydrogel was analyzed by attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, circular dichroism (CD), and field-emission scanning electron microscopy (FE-SEM). Our results revealed that the Fe3+ cations that coordinated with succinoglycan were converted to Fe2+ by a reducing agent and visible light, promoting a gel-sol conversion. The Fe3+-SG hydrogel was then successfully used for controlled drug delivery based on gel-sol conversion in the presence of reducing agents and visible light. As succinoglycan is nontoxic, it is a potential material for controlled drug delivery.

scholarly journals Excited state dynamics for visible-light sensitization of a photochromic benzil-subsituted phenoxyl-imidazolyl radical

2019 ◽  
Vol 15 ◽  
pp. 2369-2379
Author(s):  
Yoichi Kobayashi ◽  
Yukie Mamiya ◽  
Katsuya Mutoh ◽  
Hikaru Sotome ◽  
Masafumi Koga ◽  
...  
Keyword(s):  
Visible Light ◽  
Rational Design ◽  
Materials Science ◽  
Transient Absorption ◽  
Life Sciences ◽  
Transient Absorption Spectroscopy ◽  
Back Reaction ◽  
Switching Speed ◽  
Wide Range ◽  
Potential Applications

Visible-light sensitized photoswitches have been paid particular attention in the fields of life sciences and materials science because long-wavelength light reduces photodegradation, transmits deep inside of matters, and achieves the selective excitation in condensed systems. Among various photoswitch molecules, the phenoxyl-imidazolyl radical complex (PIC) is a recently developed thermally reversible photochromic molecule whose thermal back reaction can be tuned from tens of nanoseconds to tens of seconds by rational design of the molecular structure. While the wide range of tunability of the switching speed of PIC opened up various potential applications, no photosensitivity to visible light limits its applications. In this study, we synthesized a visible-light sensitized PIC derivative conjugated with a benzil unit. Femtosecond transient absorption spectroscopy revealed that the benzil unit acts as a singlet photosensitizer for PIC by the Dexter-type energy transfer. Visible-light sensitized photochromic reactions of PIC are important for expanding the versatility of potential applications to life sciences and materials science.

scholarly journals A Comprehensive Study on Light Signals of Opportunity for Subdecimetre Unmodulated Visible Light Positioning

Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5596
Author(s):  
Sander Bastiaens ◽  
Kenneth Deprez ◽  
Luc Martens ◽  
Wout Joseph ◽  
David Plets
Keyword(s):  
Visible Light ◽  
Lower Cost ◽  
Tracking System ◽  
Low Cost ◽  
Discriminative Feature ◽  
Robust Model ◽  
Significant Step ◽  
Light Signals ◽  
Signals Of Opportunity ◽  
Comprehensive Study

Currently, visible light positioning (VLP) enabling an illumination infrastructure requires a costly retrofit. Intensity modulation systems not only necessitate changes to the internal LED driving module, but decrease the LEDs’ radiant flux as well. This hinders the infrastructure’s ability to meet the maintained illuminance standards. Ideally, the LEDs could be left unmodulated, i.e., unmodulated VLP (uVLP). uVLP systems, inherently low-cost, exploit the characteristics of the light signals of opportunity (LSOOP) to infer a position. In this paper, it is shown that proper signal processing allows using the LED’s characteristic frequency (CF) as a discriminative feature in photodiode (PD)-based received signal strength (RSS) uVLP. This manuscript investigates and compares the aptitude of (future) RSS-based uVLP and VLP systems in terms of their feasibility, cost and accuracy. It demonstrates that CF-based uVLP exhibits an acceptable loss of accuracy compared to (regular) VLP. For point source-like LEDs, uVLP only worsens the trilateration-based median p50 and 90th percentile root-mean-square error p90 from 5.3cm to 7.9cm (+50%) and from 9.6cm to 15.6cm (+62%), in the 4m × 4m room under consideration. A large experimental validation shows that employing a robust model-based fingerprinting localisation procedure, instead of trilateration, further boosts uVLP’s p50 and p90 accuracy to 5.0cm and 10.6cm. When collating with VLP’s p50=3.5cm and p90=6.8cm, uVLP exhibits a comparable positioning performance at a significantly lower cost and at a higher maintained illuminance, all of which underline uVLP’s high adoption potential. With this work, a significant step is taken towards the development of an accurate and low-cost tracking system.

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