Flexible Ceramic-Polymer Composite Substrates with Spatially Variable Dielectrics for Miniaturized RF Applications

2009 ◽  
Vol 1161 ◽  
Author(s):  
Zuhal Tasdemir ◽  
Gullu Kiziltas
Keyword(s):  
Dielectric Constant ◽  
Tape Casting ◽  
Composite Films ◽  
Spatial Arrangement ◽  
Ceramic Composites ◽  
Dielectric Constants ◽  
Novel Material ◽  
The Difference ◽  
High Dielectric ◽  
Tape Cast

AbstractThe goal of this research is to develop a process suitable for producing monolithic conformal substrates with a spatial arrangement of material cells according to a particular design creating novel material systems, useful for many multi- functional electronic and Radio Frequency devices. In this study, MCT ceramics (Mg-Ca-Ti-O systems) and organic binders (polymer solution) are mixed and fabricated as films through a process called tape casting to compromise between high dielectric constant and flexibility. Prior to optimizing the process, several characterization studies are carried out: Commercial spray dried MCT powders (Transtech Inc.) with dielectric constant k=70 and k=20 were analyzed as pressed and produced into tape cast films. Dielectric properties are then measured by an Agilent 16451B material analysis kit and their microscopic behavior is examined by scanning electron microscopy. Results show that flexible composite films show a maximum dielectric constant of ε∼22 unlike their powder pressed form with ε ∼16 but their loss behavior deteriorates when compared with their sintered form and a loss tangent factor of 0.001. The difference is attributed to the air content vs. polymer presence of the material in powder pressed form. Also, these substrates naturally are no longer flexible; hence studies are focused on their tape cast form. The potential of these dielectric shades to serve as candidate constituents for producing monolithic textured polymer-ceramic-composites with controllable loss is studied further. Four properties are of prime importance: tunability of dielectric constants to achieve miniaturization, flexibility via low temperature processing of polymers and loss controllability.

A Reusable 3D Printed Cavity Resonator for Liquid Sample Characterization

2018 ◽  
Vol 2018 (1) ◽  
pp. 000389-000392
Author(s):  
Saranraj Karuppuswami ◽  
Saikat Mondal ◽  
Mohd Ifwat Mohd Ghazali ◽  
Premjeet Chahal
Keyword(s):  
Dielectric Constant ◽  
Cavity Resonator ◽  
Dielectric Constants ◽  
Sample Holder ◽  
Strongly Coupled ◽  
Weakly Coupled ◽  
Sample Characterization ◽  
3D Printed ◽  
Standard Values ◽  
High Dielectric

Abstract In this paper, additive manufacturing (3D printing) is used to fabricate and demonstrate a reusable microfluidic coupled rectangular cavity resonator for characterizing liquids in small volumes. The designed cavity operates in the fundamental TE101 mode and resonates at 4.12 GHz. The resonance of the cavity is perturbed by the sample placed in a small volume sample holder through a slot in the top cover. Two different perturbation configurations are investigated: i) strongly coupled (liquids with low to medium dielectric constants), and ii) weakly coupled (liquids with medium to high dielectric constant). The sample holder is loaded with different solvents and the shift in the resonance frequency is monitored. Based on these changes, the dielectric constant of the solvent is theoretically estimated and compared to standard values. The reusable liquid sensor holds significant potential in identifying and quantifying unknown liquid samples in the supply chain.

scholarly journals Designing Micro Bulge Structure with Uniform PS Microspheres for Boosted Dielectric Hydrophobic Blend Films

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 574
Author(s):  
Zhicai Zhu ◽  
Liqin Yao ◽  
Qilong Zhang ◽  
Hui Yang
Keyword(s):  
Dielectric Constant ◽  
Composite Films ◽  
Interfacial Polarization ◽  
Mass Ratio ◽  
Low Loss ◽  
Blend Films ◽  
Solution Blending ◽  
Blending Method ◽  
Potential Applications ◽  
High Dielectric

In this paper, homogeneous polystyrene (PS) microspheres with controllable sizes of 40 nm, 80 nm, and 120 nm were synthesized by controlling the temperature of solvothermal method. In order to explore the effect of PS microspheres on dielectric-hydrophobic properties of the composite films, the composite films containing polystyrene, Polydimethylsiloxane, and P(VDF-TrFE) with high dielectric and hydrophobicity were successfully prepared by a simple and feasible solution blending method. The dielectric constant and hydrophobicity of composite films were boosted by increasing the mass fraction of PS content and decreasing the size of PS due to the enhanced interfacial polarization and the uniform surface micro bulge structure. Meanwhile, the composite films maintain a low loss tangent. Typically, the dielectric constant with 5 wt.% 40 nm PS reached to 29 at 100Hz, which is 4 times that of PDMS/P(VDF-TrFE) (mass ratio: 2/3). Otherwise, the largest the contact angle of 126° in the same composition was remarkably larger than the pure PDMS/P(VDF-TrFE) (110°). These improved properties have more potential applications in the electric wetting devices.

Preparation and properties of thermostable well-functionalized graphene oxide/polyimide composite films with high dielectric constant, low dielectric loss and high strength via in situ polymerization

2015 ◽  
Vol 3 (18) ◽  
pp. 10005-10012 ◽  
Author(s):  
Xinliang Fang ◽  
Xiaoyun Liu ◽  
Zhong-Kai Cui ◽  
Jun Qian ◽  
Jijia Pan ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Graphene Oxide ◽  
Dielectric Loss ◽  
High Dielectric Constant ◽  
In Situ Polymerization ◽  
Composite Films ◽  
Functionalized Graphene ◽  
Functionalized Graphene Oxide ◽  
Low Dielectric ◽  
High Dielectric

Thermostable well-functionalized graphene oxide/polyimide composites with high dielectric constant and low dielectric loss were obtained at a low percolation threshold.

Preparation, Morphology and Dielectric Properties of Polyamide-6/Poly(Vinylidene Fluoride) Blends

2012 ◽  
Vol 496 ◽  
pp. 263-267
Author(s):  
Rui Li ◽  
Jian Zhong Pei ◽  
Yan Wei Li ◽  
Xin Shi ◽  
Qun Le Du
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Flexible Electronics ◽  
High Dielectric Constant ◽  
Vinylidene Fluoride ◽  
Volume Fraction ◽  
Polyamide 6 ◽  
Dielectric Constants ◽  
Poly Vinylidene Fluoride ◽  
High Dielectric

A novel all-polymeric material with high dielectric constant (k) has been developed by blending poly (vinylidene fluoride) (PVDF) with polyamide-6 (PA6). The dependence of the dielectric properties on frequency and polymer volume fraction was investigated. When the volume fraction of PA6 is 20%, the dielectric property is better than others. The SEM investigations suggest that the enhanced dielectric behavior originates from significant interfacial interactions of polymer-polymer. The XRD demonstrate that the PA6 and PVDF affect the crystalline behavior of each component. Furthermore, the stable dielectric constants of the blends could be tuned by adjusting the content of the polymers. The created high-k all-polymeric blends represent a novel type of material that are simple technology and easy to process, and is of relatively high dielectric constant, applications as flexible electronics.

Acylchloride-Functionalized Multiple-Walled Carbon Nanotubes Reinforced Polyimide for High Dielectric Properties

2011 ◽  
Vol 239-242 ◽  
pp. 2655-2658
Author(s):  
Heng Feng Li ◽  
Guo Wen He ◽  
Jun Li ◽  
Jun Chen ◽  
Jiang Cong Chen
Keyword(s):  
Carbon Nanotubes ◽  
Composite Films ◽  
Dielectric Constants ◽  
Acid Mixture ◽  
Mass Fractions ◽  
The Matrix ◽  
Multi Walled Carbon Nanotubes ◽  
Polyimide Matrix ◽  
High Dielectric ◽  
Walled Carbon Nanotubes

A series of polyimide composites with various mass fractions of multi-walled carbon nanotubes (MWNTs) were prepared by in situ polymerization. MWNTs were treated with an acid mixture and sulfoxide chloride in turn to increase the chemical compatibility of carbon nanotubes with the polyimide matrix. The modified MWNTs are dispersed homogeneously in the matrix while the structure of the PI and MWNTs structures are stable in the preparation process. The composite films hold preferable thermal stability as same as the pure PI. The dielectric constants of the composites decreased with the increasing frequency and increase sharply with the adding of MWNTs.

New High-Dielectric-Constant Polymer-Ceramic Composites

2004 ◽  
Vol 847 ◽  
Author(s):  
Milind Arbatti ◽  
Xiaobing Shan ◽  
Z.-Y. Cheng
Keyword(s):  
Dielectric Constant ◽  
Vinylidene Fluoride ◽  
Ceramic Powder ◽  
Ceramic Composites ◽  
Flexible Composites ◽  
Giant Dielectric ◽  
Poly Vinylidene Fluoride ◽  
Solution Cast ◽  
Giant Dielectric Constant ◽  
High Dielectric

ABSTRACTA ceramic-powder polymer composite, making use of a newly developed ceramics - CaCu3Ti4O12 (CCTO) - that has a giant dielectric constant as the filler, is developed. In this work, poly(vinylidene fluoride - trifluoroethylene) [P(VDF-TrFE)] 55/45 mol% copolymer was used as matrix. It is found that the wettability between the copolymer and CCTO is poor, which makes the solution cast composites have a poor uniformity. The uniformity and thus the dielectric constant of the composites can be significantly improved by using hot-press technology to form “sandwich” structure. It is also found that the thermal annealing process can improve the dielectric constant of the composite. The experimental data show that for the flexible composites the dielectric constant at 1 kHz can reach more than 300 at room temperature and more than 700 at ∼70 °C.

scholarly journals Investigating the dielectric properties of barium titanate nanocomposites using transmission electron microscopy image processing

MRS Advances ◽  
2021 ◽  
Author(s):  
Gio Ferro ◽  
Dithi Ganjam ◽  
Maia Gibson ◽  
Katie Partington ◽  
Akshay Trikha ◽  
...  
Keyword(s):  
Image Processing ◽  
Dielectric Constant ◽  
Energy Storage ◽  
Barium Titanate ◽  
Computational Models ◽  
Transmission Electron Microscopy Image ◽  
Dielectric Behavior ◽  
Dielectric Constants ◽  
Transmission Electron ◽  
High Dielectric

AbstractBarium titanate (BTO) is a ferroelectric perovskite material used in energy storage applications because of its high dielectric constant. A previous study showed that the dielectric constant for BTO nanoparticles drastically increases to over 15,000 at a particle size of 70 nm. This result is highly contested, but its implications to energy storage motivated our investigation into the dielectric constants of BTO nanoparticles that are incorporated into a polymer matrix. We developed a novel method of using image processing techniques on transmission electron microscope images of BTO-polymer nanocomposites. Data on the positions, shapes, sizes, and orientations of BTO nanoparticles were used to build more realistic computational models that simulate the dielectric behavior of the nanocomposites. Here, we investigate the relationship between regions of enhanced electric field and the composite dielectric constant.

Capacitor Strain Sensor for Enhancing Feedback to Patients Recovering From a Stroke

2020 ◽  
Author(s):  
Phil Denen ◽  
Matthew Colachis ◽  
Amy M. Heintz ◽  
Krenar Shqau ◽  
Andrew Sweeney ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Dielectric Constant ◽  
Strain Sensor ◽  
Strain Sensors ◽  
Single Wall Carbon Nanotubes ◽  
Novel Material ◽  
Strain Sensor Array ◽  
Capacitive Strain ◽  
High Dielectric

Abstract Embedded sensors in footwear are of interest for providing feedback on mobility and gait. The most sensitive location is within the sole, requiring development of new materials that have the required functional and mechanical properties. We are developing capacitive strain sensors. The performance of such sensorsis dictated by two fundamental materials properties: dielectric constant (ε) and hardness. The sensitivity is improved by a high dielectric constant and low hardness. This paper describes a novel material that combines a composite elastomeric polymer and single wall carbon nanotubes (SWCNTs). The optimum SWCNT loading in a polyurethane with 80A shore hardness was determined to be 0.1 vol% which delivered a high SNR and maintained its mechanical properties (hardness). Data collected from a shoe strain sensor array of this material can be used for automatic recognition of postures and activities, for characterization of extremity use, and to provide behavioral enhancing feedback to patients recovering from a stroke.

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