Article
Polymer Science
Zhubing Han, Hancheng Qin, Xin Chen, Wenhan Xu, Yang Liu, J. Bernholc, Qing Wang
Summary: The incorporation of comonomers in PVDF-based ferroelectric polymers has been widely used to modify their structures and properties. Previous studies have shown that large-sized comonomers can induce relaxor ferroelectricity, but this study demonstrates that a small-sized comonomer can preferentially adopt a polar all-trans conformation, resulting in terpolymers with robust ferroelectricity and enhanced transition temperature and coercive field. This work systematically investigates the effects of comonomer size on the microstructures and properties of ferroelectric polymers.
Article
Polymer Science
Kanyapak Silakaew, Prasit Thongbai
Summary: This study balanced the significantly increased dielectric permittivity and effectively retained tan delta using Ag-nBT and μBT particles through a two-step concept, showing improved ε and reduced tan δ.
Article
Chemistry, Multidisciplinary
Chenchen Wang, Yang Zhang, Bowen Zhang, Bo Wang, Jinxi Zhang, Long-Qing Chen, Qiming Zhang, Zhong Lin Wang, Kailiang Ren
Summary: Flexoelectricity-induced flexophotovoltaic effect has been demonstrated in a KNN/PVDF-TrFE nanocomposite, significantly enhancing the photovoltaic current. The curved K/P-20 composite shows a 13.9% increase in the photovoltaic current compared to the flat nanocomposite, indicating great potential for PVDF-based nanocomposites in ferroelectric memory device applications.
Article
Polymer Science
Fatima Ezzahra Bouharras, Massimiliano Labardi, Elpidio Tombari, Simone Capaccioli, Mustapha Raihane, Bruno Ameduri
Summary: The dielectric properties of PVDF-g-BT core-shell structured nanocomposites obtained by RAFT polymerization were investigated. The dielectric constant increased with the addition of BT, exhibiting a larger increase than predicted by usual modeling methods for composite materials, due to the effect of the interfacial core-shell structure. PVDF's known dielectric relaxations were observed in both the neat polymer and its nanocomposites, unaffected by the presence of nanoparticles. A relaxation process due to interfacial polarization was found at higher temperatures, attributed to the high crystallinity of the materials produced by RAFT.
Article
Polymer Science
Juliane C. Kade, Biranche Tandon, Jan Weichhold, Dario Pisignano, Luana Persano, Robert Luxenhofer, Paul D. Dalton
Summary: This study successfully fabricated well-defined microperiodic structures of the copolymer Poly(vinylidene fluoride-co-trifluoroethylene) using the melt electrowriting (MEW) technique, and demonstrated the electromechanical response of the fibers. This research lays the foundation for the application of electroactive polymers in various fields.
POLYMER INTERNATIONAL
(2021)
Article
Polymer Science
Thulasinath Raman Venkatesan, David Smykalla, Bernd Ploss, Michael Wuebbenhorst, Reimund Gerhard
Summary: The effects of thermal processing on the micro- and nanostructural features and relaxor-ferroelectric properties of a P(VDF-TrFE-CFE) terpolymer were investigated. Annealing reduces the Curie transition temperature and shifts the ferroelectric phase fraction, leading to relaxor-ferroelectric behavior. Changes in transition temperatures are related to alterations in hysteresis curves.
Article
Materials Science, Multidisciplinary
Rui Qiao, Haoran Xu, Shaonan Chen, Sheng Chen, Hang Luo, Dou Zhang
Summary: Dielectric polymers are crucial in modern electronic and electrical applications due to their easy processing, lightweight, and high breakdown strength. By combining different polymer advantages, the dielectric polymer blending method is a feasible option to address the issue of high ε(r) and breakdown strength in dielectric homopolymers. Experimental results showed the significant impact of n-type semiconductive polymer on the dielectric and energy storage properties of PPDI/PVTC blends.
ACS APPLIED POLYMER MATERIALS
(2021)
Review
Materials Science, Multidisciplinary
X. W. Wang, J. T. Fan, M. Manikandan, B. H. Zhang, J. N. Guo, J. Y. Chen, F. Yang, M. M. Zheng, H. X. Zhang, M. Z. Hou, Y. X. Fu, S. Y. Shang, Y. C. Hu, J. Shang, S. Q. Yin
Summary: This paper reviews the important aspects and recent progress of poly (vinylidene fluoride)-based composites with lead-free ferroelectric ceramics for high energy density capacitors. It discusses the comprehensive effects of filler shape, core-shell structure, layered structure, and interface effect on the dielectric properties, breakdown strength, and energy density of the composites.
JOURNAL OF MATERIALS SCIENCE
(2023)
Article
Nanoscience & Nanotechnology
Qingqing Li, Jinghua Zhao, Baosheng He, Zhijun Hu
Summary: PVDF, a ferroelectric polymer with the polar beta-phase, has the highest dipolar moment and piezoelectric response. The development of flexible electronics highly requires effective methods for producing beta-PVDF.
Article
Materials Science, Multidisciplinary
Huijian Ye, Shujie Hu, Bo Han, Lixin Xu
Summary: In this study, a polymer composite film with high energy capability was successfully prepared by combining few-layer boron nitride nanosheets (BNNSs) synthesized with hyperbranched copolymer interface and polymer matrix. The nanocomposite exhibited a large dielectric constant and discharged energy density, making it a promising candidate for flexible film capacitors.
JOURNAL OF MATERIALS SCIENCE
(2022)
Article
Nanoscience & Nanotechnology
Zhiwen Zhu, Guanchun Rui, Ruipeng Li, Hezhi He, Lei Zhu
Summary: This study investigated the structure and electrostrictive properties of relaxor ferroelectric (RFE) poly(vinylidene fluoride-cotrifluoroethylene-co-chlorotrifluoroethylene) [P(VDF-TrFE-CTFE)] random terpolymers films to understand the mechanism of electrostriction. It was found that reducing the ferroelectric nonlinearity of the RFE terpolymer led to higher electrostriction performance at lower driving fields, providing a potential pathway for designing new electrostrictive polymers with improved performance.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Inorganic & Nuclear
Wu Si-Chen, Guo Yi-Ting, Liu Shu-Hang, Liu Zhen-Nan, Shi Fang-Jun, Li Ning, Xu Jie, Gao Feng
Summary: Ba0.6Sr0.4TiO3 (BST)/poly(vinylidene fluoride) (PVDF)-poly(methyl methacrylate) (PMMA) composite films were prepared by tape casting and hot pressing. The effects of PMMA content on the phase structure and electrical properties of the composites were studied. The results showed that the BST phase was uniformly dispersed in the polymer matrix. With the increase of PMMA content, the dielectric constant of the composites is negatively correlated with the breakdown strength and dielectric tunability. The BST/PVDF-PMMA(15) composite with PMMA content (volume fraction) of 15% showed the best dielectric properties.
CHINESE JOURNAL OF INORGANIC CHEMISTRY
(2022)
Article
Polymer Science
Edgar Gutierrez-Fernandez, Jose Sena-Fernandez, Esther Rebollar, Tiberio A. Ezquerra, Francisco J. Hermoso-Pinilla, Mikel Sanz, Oscar Galvez, Aurora Nogales
Summary: Ferroelectric polymer nanoparticles of PVDF were prepared using dialysis nano-precipitation. The nanoparticles showed piezoelectric response as observed by PFM. The ferroelectric behavior was attributed to the presence of ferroelectrically active crystalline phases of PVDF in the nanoparticles (mainly beta and gamma phases) as demonstrated by DSC, FTIR, and XRD. The combination of the preparation method and temperature treatment can tune the ferroelectric properties of PVDF homopolymer nanoparticles.
Article
Chemistry, Physical
Jian-Ping Zeng, Jun-Feng Liu, Hua-Dong Huang, Shao-Cong Shi, Ben-Hao Kang, Chen Dai, Li-Wei Zhang, Zhi-Chao Yan, Florian J. Stadler, Yan-Bing He, Yan-Fei Huang
Summary: This study proposes a new method to improve the ionic conductivity of solid-state polymer electrolytes (SPEs) by enhancing the polarization of polymers using P(VDF-TrFE) as the matrix. The results show that P(VDF-TrFE) has a higher remnant polarization compared to PVDF, facilitating the dissociation of LiN(SO2CF3)2 and leading to significantly enhanced ionic conductivity. Stable cycling performance is also achieved in Li/P(VDF-TrFE) SPEs/Li batteries.
JOURNAL OF MATERIALS CHEMISTRY A
(2022)
Article
Polymer Science
Zhubing Han, Yang Liu, Xin Chen, Wenhan Xu, Qing Wang
Summary: This study enhances the longitudinal piezoelectric coefficients of PVDF-based ferroelectric polymers through the synthesis and characterization of terpolymers. The terpolymers exhibit a mixture of ferroelectric and relaxor phases, with the best piezoelectric performance observed in the terpolymer with a composition of VDF/TrFE/CTFE = 64.5/33.1/2.4 mol%. The introduction of CTFE facilitates the formation of the relaxor phase.
Article
Engineering, Electrical & Electronic
Monica Lamba, Himanshu Chaudhary, Kulwant Singh
Summary: The aim of this paper is to analyze and evaluate the sensitivity and non-linearity of a graphene piezoresistive MEMS force sensor by optimizing its geometrical parameters. The study identified important factors affecting sensitivity and non-linearity and used the Taguchi optimization method to find the optimal combination of microcantilever and piezoresistor dimensions. The designed sensor demonstrated high sensitivity and low non-linearity.
IETE JOURNAL OF RESEARCH
(2022)
Article
Nanoscience & Nanotechnology
V. H. Shafeeq, Subash Cherumannil Karumuthil, K. Juraij, Soney Varghese, Sujith Athiyanathil, Unnikrishnan Gopalakrishna Panicker
Summary: Piezoelectric polymer mats were fabricated using electrospinning technique and their ferro-piezoelectric features were confirmed through electrostatic force microscopy and dynamic-contact EFM. The samples showed piezoelectric responses to various activities, indicating the promising potential of fabricating user-friendly piezoelectric mats for physiological motion-sensing applications.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Physics, Condensed Matter
Amit Kumar Singh, Rohit Singh, Kulwant Singh, Amit Rathi
Summary: The self-consistent k center dot p computation results show a significant improvement in optical gain in AlSb/InGaAsP/GaAsSb type-II ultra-thin quantum-well heterostructures compared to InGaAsP/GaAsSb type-II structures. This improvement is attributed to interband resonant tunnelling effect and the band alignment due to the presence of GaAsSb layer. Furthermore, a narrower optical gain spectrum is observed in AlSb/In0.5Ga0.5As0.8P0.2/GaAs0.5Sb0.5 QW heterostructure, indicating its potential in optical performance.
EUROPEAN PHYSICAL JOURNAL B
(2021)
Article
Engineering, Electrical & Electronic
Amit Agrawal, Ashish Shrivastava, Kulwant Singh, Bidyut Mahato, Shubham Tiwari, Amit Rai
Summary: This article introduces a new approach for solving the small signal SSA model of PWM SEPIC under DCM, using a novel method based on inductor current variation and a unique correction matrix to achieve better results in the design of a 75 W power supply. The new technique's frequency response is much closer to simulation results compared to traditional methods, showing high predictive capabilities for DC-DC converters operating in DCM.
INTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS
(2022)
Article
Thermodynamics
Shivanand H. Nannuri, Sana Adnan, C. K. Subash, C. Santhosh, Sajan D. George
Summary: The influence of Mn2+ ion concentration and thermal annealing temperature on the structural and luminescence properties of NaYF4:Yb, Er microcrystals was investigated. The addition of Mn2+ ions did not change the phase of the material, but affected the luminescence properties. The maximum positive influence on upconversion luminescence was observed for the sample co-doped with 3 mol% Mn2+ ions, while higher concentrations led to quenching. The enhancement factors of green and red emissions depended on the annealing temperature, with the highest enhancement observed for the sample annealed at 600 degrees C and co-doped with 3 mol% Mn2+ ions.
NANOSCALE AND MICROSCALE THERMOPHYSICAL ENGINEERING
(2022)
Article
Engineering, Electrical & Electronic
M. Arjun Hari, Subash Cherumannil Karumuthil, Soney Varghese, Lintu Rajan
Summary: This study explores a sandwich assembly based on piezoelectric polyvinylidene difluoride - zinc oxide (PVDF-ZnO) nanocomposite layer as a tactile sensor, overcoming challenges associated with PVDF-based sensors. Experimental results demonstrate that the nanocomposite sensor performs better, generating higher voltage under the same applied force, and showing excellent potential in detecting finger bending action.
IEEE SENSORS JOURNAL
(2022)
Article
Engineering, Electrical & Electronic
Himanshu Priyadarshi, Kulwant Singh, Ashish Shrivastava
Summary: This paper presents the facile synthesis and characterization of maghemite nanoparticles in the context of energy storage device technology. The experimental study reveals the high surface area, crystallinity, and magnetic properties of the nanoparticles, which can be utilized for state estimation and conductivity modulation in energy storage devices. Additionally, the affordability of maghemite electrode iron batteries is beneficial for scaling up renewable energy storage technology.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2022)
Article
Engineering, Electrical & Electronic
Monica Lamba, Himanshu Chaudhary, Kulwant Singh, Premraj Keshyep, Vibhor Kumar
Summary: The aim of this study was to design a bi-axial piezoresistive MEMS force sensor that can sense forces in the nano-Newton range with flexibility and high sensitivity. The combination of PDMS as the substrate material and graphene as the piezoresistors was used. The force applied to the cantilever beam generates displacement, which is converted into voltage using a smart piezoresistive sensing mechanism. Finite element analysis was used to design and simulate the force sensor, achieving force sensitivity and stiffness values in different directions.
MICROSYSTEM TECHNOLOGIES-MICRO-AND NANOSYSTEMS-INFORMATION STORAGE AND PROCESSING SYSTEMS
(2022)
Article
Materials Science, Multidisciplinary
Alina Peethan, Mikitha Pais, Padmalatha Rao, Kulwant Singh, Sajan D. George
Summary: Inspired by superhydrophobic surfaces in nature, researchers have fabricated superhydrophobic and liquid-infused porous surfaces (SLIPS) to solve engineering problems, including metal corrosion. The study shows that the H-SLIPS, a hydrophobic, superhydrophobic, hydrophobic lubricant-infused surface, exhibits better self-healing properties and lubricant layer stability compared to the SH-SLIPS. The research emphasizes the importance of infused oil stability for applications like anti-corrosion properties and provides insights into the development of new materials for corrosion resistance.
MATERIALS CHEMISTRY AND PHYSICS
(2022)
Article
Physics, Multidisciplinary
Mona Sharma, Smita Pareek, Kulwant Singh
Summary: The reconfiguration technique is the most efficient approach for mitigating the mismatch losses due to partial shading in large-scale solar photovoltaic systems. The proposed rules for reconfiguration allow for multiple options in selecting the location of shaded panels within an array. The results show significant performance enhancement, with a 25% improvement in a short wide shading pattern and 6.4% improvement in short narrow and center shading patterns.
Article
Engineering, Multidisciplinary
Jai Prakash Mishra, Kulwant Singh, Himanshu Chaudhary
Summary: Wave height is an important consideration in maritime projects. Traditional wave height forecasting methods require complex numerical wave prediction models, while machine learning techniques can predict wave height without prior knowledge of complex interactions. This research aims to predict wave height using MEMS, IoT, and ML-based approaches.
MEASUREMENT SCIENCE AND TECHNOLOGY
(2023)
Article
Physics, Multidisciplinary
Ankur Saxena, Mahesh Kumar, Dhaneshwar Mishra, Kulwant Singh
Summary: This study analyzes an integrated microfluidic pressure sensing mechanism in a microfluidic device, which consists of a poly dimethyl siloxane (PDMS) based material with a microcantilever integrated on one side of the microchannel. The pressure of fluid in the microchannel is measured by the deflection of the PDMS microcantilever. The results show that the Pi-shaped microcantilever achieved the maximum deflection in fluid plasma (37.05 μm) and water (30.98 μm) at a fluid inlet velocity of 8000 μm/s.
Article
Engineering, Multidisciplinary
Mahesh Kumar, Akshay Vasage, Gajanan Kulkarni, Onkar Padhye, Shivram Kerkar, Mridul Gupta, Kulwant Singh
Summary: This study addresses the speed asynchronization issue in smart walking assistance devices and achieves speed synchronization through mathematical modeling and effective speed control techniques. The power consumption of the device is also analyzed, resulting in significant energy savings.
ENGINEERING RESEARCH EXPRESS
(2023)
Article
Chemistry, Physical
Subash Cherumannil Karumuthil, Mukhesh K. Ganesha, Indrajit Mondal, Ashutosh K. Singh, Giridhar U. Kulkarni
Summary: This study presents a cost-effective fabrication method for a dual-functional polymeric electrochromic device. By using a chemically synthesized conducting polymer as the electrochromic layer and a low-cost transparent conducting electrode, the smart window exhibits excellent optical contrast, rapid switching ability, outstanding cycling stability, and energy storage capability.
JOURNAL OF MATERIALS CHEMISTRY A
(2022)
Article
Materials Science, Multidisciplinary
Jayprakash Vijay, A. K. Singh, P. K. Jain, P. A. Alvi, Kulwant Singh, Amit Rathi
Summary: The study focused on a nanoscale-heterostructure composed of AlAsSb/InGaAs/GaAsSb on a GaAs substrate, examining wavefunctions, dispersion profile, dipole transition matrix elements behavior, and optical gain. Using a 6-band k.p method to model the heterostructure, an optical gain of around 6500 cm(-1) was achieved at the 1460 nm wavelength with an injected carrier concentration of 5 x 10(12)/cm(2) at room temperature. Effects of externally applied strain and temperature on tuning optical gain and wavelength in the NIR range were also investigated.
OPTOELECTRONICS AND ADVANCED MATERIALS-RAPID COMMUNICATIONS
(2021)
