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Synthesis of Green and Red-Emitting Polymethyl Methacrylate Composites Grafted from ZnAl 2O 4:Mn-Bonded GO via Surface-Initiated Atom Transfer Radical Polymerization. Polymers (Basel) 2022; 14:polym14173689. [PMID: 36080763 PMCID: PMC9460467 DOI: 10.3390/polym14173689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 08/21/2022] [Accepted: 08/30/2022] [Indexed: 11/16/2022] Open
Abstract
A novel dual green and red-emitting photoluminescent polymer composite ZnAl2O4:Mn-bonded GO/polymethyl methacrylate (PMMA) was synthesized in a single-step reaction by surface-initiated atom transfer radical polymerization (SI-ATRP). The polymer chain was surface-initiated from the ZnAl2O4:Mn/GO, and the final products have a homogenous photoluminescent property from ZnAl2O4:Mn and better mechanical properties strengthened by graphene oxide (GO). The morphologies of ZnAl2O4:Mn/GO and the polymer composites were verified by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). X-ray diffraction analysis (XRD) revealed the two valence states of Mn (Mn2+, Mn4+) existing in the ZnAl2O4 host lattice, while Fourier-transform infrared spectroscopy (FTIR) spectra proved the transference of the active group, C-Br, from the initiator to the monomer during the polymerization. Gel permeation chromatography (GPC) shows the narrow dispersity of polymer composites fabricated through SI-ATRP. The SEM and FTIR results show the successful ‘graft’ of the polymer chains from the surface of ZnAl2O4:Mn/GO. The dual green and red-emitting polymer composites were synthesized, confirmed by the photoluminescence (PL) and photoluminescence excitation (PLE) results.
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Vijjapu MT, Fouda ME, Agambayev A, Kang CH, Lin CH, Ooi BS, He JH, Eltawil AM, Salama KN. A flexible capacitive photoreceptor for the biomimetic retina. LIGHT, SCIENCE & APPLICATIONS 2022; 11:3. [PMID: 34974516 PMCID: PMC8720312 DOI: 10.1038/s41377-021-00686-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 11/06/2021] [Accepted: 11/23/2021] [Indexed: 05/06/2023]
Abstract
Neuromorphic vision sensors have been extremely beneficial in developing energy-efficient intelligent systems for robotics and privacy-preserving security applications. There is a dire need for devices to mimic the retina's photoreceptors that encode the light illumination into a sequence of spikes to develop such sensors. Herein, we develop a hybrid perovskite-based flexible photoreceptor whose capacitance changes proportionally to the light intensity mimicking the retina's rod cells, paving the way for developing an efficient artificial retina network. The proposed device constitutes a hybrid nanocomposite of perovskites (methyl-ammonium lead bromide) and the ferroelectric terpolymer (polyvinylidene fluoride trifluoroethylene-chlorofluoroethylene). A metal-insulator-metal type capacitor with the prepared composite exhibits the unique and photosensitive capacitive behavior at various light intensities in the visible light spectrum. The proposed photoreceptor mimics the spectral sensitivity curve of human photopic vision. The hybrid nanocomposite is stable in ambient air for 129 weeks, with no observable degradation of the composite due to the encapsulation of hybrid perovskites in the hydrophobic polymer. The functionality of the proposed photoreceptor to recognize handwritten digits (MNIST) dataset using an unsupervised trained spiking neural network with 72.05% recognition accuracy is demonstrated. This demonstration proves the potential of the proposed sensor for neuromorphic vision applications.
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Affiliation(s)
- Mani Teja Vijjapu
- Sensors lab, Advanced Membranes and Porous Materials Center, Computer, Electrical and Mathematical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Mohammed E Fouda
- Communication and Computing Systems Lab, Computer, Electrical and Mathematical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Kingdom of Saudi Arabia
- Department of Electrical Engineering and Computer Science, University of California-Irvine, Irvine, CA, 92612, USA
| | - Agamyrat Agambayev
- Sensors lab, Advanced Membranes and Porous Materials Center, Computer, Electrical and Mathematical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Kingdom of Saudi Arabia
- Department of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, AZ, USA
| | - Chun Hong Kang
- Computer, Electrical and Mathematical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Chun-Ho Lin
- Computer, Electrical and Mathematical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Boon S Ooi
- Computer, Electrical and Mathematical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Jr-Hau He
- Computer, Electrical and Mathematical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Kingdom of Saudi Arabia
- Department of Materials Science and Engineering, City University of Hong Kong, Hong Kong SAR, China
| | - Ahmed M Eltawil
- Communication and Computing Systems Lab, Computer, Electrical and Mathematical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Kingdom of Saudi Arabia
- Department of Electrical Engineering and Computer Science, University of California-Irvine, Irvine, CA, 92612, USA
| | - Khaled N Salama
- Sensors lab, Advanced Membranes and Porous Materials Center, Computer, Electrical and Mathematical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Kingdom of Saudi Arabia.
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Fimbel A, Abensur T, Le MQ, Capsal JF, Cottinet PJ. Accurate Electroadhesion Force Measurements of Electrostrictive Polymers: The Case of High Performance Plasticized Terpolymers. Polymers (Basel) 2021; 14:24. [PMID: 35012051 PMCID: PMC8747691 DOI: 10.3390/polym14010024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 12/09/2021] [Accepted: 12/14/2021] [Indexed: 11/28/2022] Open
Abstract
Electroadhesion is a phenomenon ruled by many characteristic intrinsic parameters. To achieve a good adhesion, efficient and durable, a particular attention must be provided to the adhesion forces between the involved parts. In addition to the size and geometry of electrodes, parameters of materials such as dielectric constant, breakdown electric field, and Young's modulus are key factors in the evaluation of electroadhesion efficiency for electrostrictive polymers and electroactive devices. By analyzing these material parameters, a method is proposed to justify the choice of polymer matrices that are fit to specific electroadhesion applications. Another purpose of this work aims to demonstrate a possibility of accurately measuring the electroadhesion force. This physical parameter has been usually estimated through equations instead, because of the complexity in setup implementation to achieve highly precise measure. Comparisons based on the parameters criterion reveal that besides the intrinsic properties of material, some other parameters relating to its physical phenomena (e.g., saturation of dipolar orientation under high electric field leads to decrease dielectric constant), or physical behavior of the system (i.e., surface roughness reduces the active electrode area) must be thoroughly considered. Experimental results pointed out that plasticized terpolymer leads boosted electroadhesion performance compared to the other counterparts, up to 100 times higher than conventional polymers. The developed materials show high potential in applications of active displacement control for electrostrictive actuation.
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Affiliation(s)
- Amaury Fimbel
- Electrical Department, Ladoua Campus, University Lyon, INSA-Lyon, LGEF, EA682, 69621 Villeurbanne, France; (A.F.); (M.-Q.L.); (J.-F.C.)
| | - Thierry Abensur
- ArianeGroup SAS, 66 Route de Verneuil, 78130 Les Mureaux, France;
| | - Minh-Quyen Le
- Electrical Department, Ladoua Campus, University Lyon, INSA-Lyon, LGEF, EA682, 69621 Villeurbanne, France; (A.F.); (M.-Q.L.); (J.-F.C.)
| | - Jean-Fabien Capsal
- Electrical Department, Ladoua Campus, University Lyon, INSA-Lyon, LGEF, EA682, 69621 Villeurbanne, France; (A.F.); (M.-Q.L.); (J.-F.C.)
| | - Pierre-Jean Cottinet
- Electrical Department, Ladoua Campus, University Lyon, INSA-Lyon, LGEF, EA682, 69621 Villeurbanne, France; (A.F.); (M.-Q.L.); (J.-F.C.)
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