Electromechanical coupling in electroactive polymers (EAPs) has been widely applied for actuation and is also being increasingly investigated for sensing chemical and mechanical stimuli. EAPs are a...

https://royalsocietypublishing.org/doi/pdf/10.1098/rsfs.2016.0026

Electroactive polymers for sensing

Electroactive polymers (EAPs) are materials that respond to electrical stimulation by exhibiting significantly large strains (to a maximum of a few hundred %) and vice versa. Thanks to their unique behaviors, EAPs have been widely and increasingly applied for sensing and actuating applications. EAPs are a promising material with many attractive properties such as fast electro-mechanical response, high mechanical and chemical stability, flexibility, low modulus, high strain capabilities, and shape adaptability. These features make them attractive for innovative applications such as wearable fabric sensors for IoT products and artificial muscles as bio-friendly actuators. In this article, we have presented a brief overview of electronic EAPs, especially PVDF-based materials, dielectric elastomers such as silicone and acrylic materials for sensors and actuators by focusing on their operation mechanisms and applications.

https://iopscience.iop.org/article/10.1088/2631-6331/ab0f48/pdf

PVDF-based ferroelectric polymers and dielectric elastomers for sensor and actuator applications: a review

Preparation of PA11/BaTiO3 nanocomposite powders with improved processability, dielectric and piezoelectric properties for use in selective laser sintering

Thin films of ferroelectric β-phase poly(vinylidene fluoride) (PVDF) were spin-coated from a solution that contained small amounts of the ionic liquid (IL) 1-ethyl-3-methylimidazolium nitrate. A remanent polarization of 60 mC/m2 and a quasi-static pyroelectric coefficient of 19 μC/m2K at 30 °C were observed in the films. It is suggested that the IL promotes the formation of the β phase through dipolar interactions between PVDF chain-molecules and the IL. The dipolar interactions are identified as Coulomb attraction between hydrogen atoms in PVDF chains and anions in IL. The strong crystallinity increase is probably caused by the same dipolar interaction as well.

Ionic-liquid-induced ferroelectric polarization in poly(vinylidene fluoride) thin films

Bio-based polyamide 11 and natural halloysite nanotubes (HNTs) were used for the preparation of PA-11/HNT nanocomposites with varying nanotubes concentrations by melt extrusion using a masterbatch dilution process. The prepared nanocomposites were analyzed for microstructural changes, transparency, thermal stability, rheological behavior, dielectric, and mechanical properties. The HNT nanotubes are well dispersed in PA-11 matrix in the studied composition range as shown by microscopy and spectrophotometry. Interestingly, good halloysite dispersion in PA-11 matrix increases the tensile strength and Young modulus of PA-11 without sacrificing the ductility. Highly dispersed nanotubes also bring favorable changes in the thermal stability, dielectric, and rheological characteristics of PA-11. Additionally, glass transition temperature, crystallization temperature, and degree of crystallinity of the nanocomposites tend to increase with increase in nanotubes loading. Thus, PA-11 can become a tailor-made material with multifunctional characteristics, thanks to the addition of HNTs. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Highly dispersed polyamide‐11/halloysite nanocomposites: Thermal, rheological, optical, dielectric, and mechanical properties

Ferroelectric polyamide 11 films were prepared by melt-quenching, cold-drawing and electrical poling. Their ferroelectricity was studied by means of dielectric-hysteresis measurements. A remnant polarisation of up to 35 mC/m/sup 2/ and a coercive field of 75 MV/m were obtained. The piezoelectric d/sub 33/ coefficient and the pyroelectric coefficient of the films are reduced by annealing just below the melting region, but remain at about 3 pC/N and 8 /spl mu/C/(m/sup 2/K), respectively, during further heat treatment. Differential scanning calorimetry (DSC), dielectric relaxation spectroscopy (DRS) and thermally stimulated depolarisation (TSD) were applied for investigating the conformational changes induced by melt-quenching, cold-drawing and annealing. The results indicate that the cold-drawn film mainly consists of a rigid amorphous phase which exhibits considerably lower conductivity, no glass transition and consequently no dielectric /spl alpha/ relaxation. Instead, an /spl alpha//sub r/ relaxation is found, which is related to chain motions in regions of the rigid amorphous phase where the amide-group dipoles are not perfectly ordered. Annealing removes imperfectly ordered structures, but does not affect the ferroelectric polarisation. Therefore, it may be concluded that essentially the /spl alpha//sub r/ relaxation causes the thermally nonstable part of the piezo- and pyroelectricity in polyamide 11.

Dielectric relaxation in piezo-, pyro- and ferroelectric polyamide 11

Ferroelectric materials are characterized by a spontaneous polarization which can be switched by an applied electric field. In many ferroelectrics the magnitude of the reversed polarization is observed to decrease when the polarization is switched many times. In ferroelectric polymers a significant decrease in reversed polarization may be observed after /spl sim/3000 cycles, and the reduction can be /spl sim/50% of the initial value. Infrared and X-ray observations show a conversion of the non-polar /spl alpha/ crystal form to the ferroelectric /spl beta/ form in samples containing a mixture of the crystal phases. However there appear to be no crystalline changes of such a nature as would lead to fatigue. A decrease in dielectric loss at low frequencies is observed in all fatigued samples, suggesting that space charge trapping may be involved in the fatigue process.

Polarization fatigue in ferroelectric polymers

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

I.L. Guy

Author Tools

Chat about Author

Papers

Dielectric relaxation in piezo-, pyro- and ferroelectric polyamide 11

Polarization fatigue in ferroelectric polymers