Journal ArticleDOI
Ultraviolet-induced discharge currents and reduction of the piezoelectric coefficient in cellular polypropylene films
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TLDR
In this paper, the effects of UV irradiation on the piezoelectric d33 coefficient was studied by monitoring thickness-extension resonances in the dielectric spectrum, and it was shown that prolonged irradiation at wavelengths below 210 nm led to a reduction of the d33 coefficients caused by partial discharge of the polymer foam.Abstract:
Photostimulated discharge spectroscopy of cellular polypropylene films between 200 and 400 nm showed the existence of at least three distinct trapping levels at 4.6, 5.6, and 6.3 eV. The effects of UV irradiation on the piezoelectric d33 coefficient was studied by monitoring thickness-extension resonances in the dielectric spectrum. Prolonged irradiation at wavelengths below 210 nm led to a reduction of the piezoelectric coefficient, caused by partial discharge of the polymer foam.read more
Citations
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New materials for micro-scale sensors and actuators An engineering review
Stephen A. Wilson,Renaud Jourdain,Qi Zhang,Robert A. Dorey,Christopher R. Bowen,Magnus Willander,Qamar Ul Wahab,Safaa Al-Hilli,Omer Nur,Eckhard Quandt,Christer Johansson,E. Pagounis,Manfred Kohl,Jovan Matovic,Björn Samel,Wouter van der Wijngaart,Edwin Jager,Daniel O Carlsson,Zoran Djinovic,Michael Wegener,Carmen Moldovan,Rodica Iosub,E. Abad,Michael Wendlandt,Cristina Rusu,Katrin Persson +25 more
TL;DR: In this paper, a detailed overview of developments in transducer materials technology relating to their current and future applications in micro-scale devices is provided. And a short discussion of structural polymers that are extending the range of micro-fabrication techniques available to designers and production engineers beyond the limitations of silicon fabrication technology is presented.
Journal ArticleDOI
Dielectric resonance spectroscopy: a versatile tool in the quest for better piezoelectric polymers
TL;DR: In this paper, the theoretical foundations of piezoelectric resonance, examines the experimental aspects, and reviews recent applications in the field of polymers. But the authors do not discuss the application of this technique in actuator applications.
Journal ArticleDOI
Identification of electron and hole trap based on isothermal surface potential decay model
TL;DR: In this paper, the authors combine the isothermal relaxation current theory and surface potential decay together and present a model called ISPD, which features that energy distribution of electron or hole-type traps can be discriminated with negative or positive corona charging, respectively.
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Piezoelectric Polyethylene Terephthalate (PETP) Foams – Specifically Designed and Prepared Ferroelectret Films
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Thermal and Temporal Stability of Ferroelectret Films Made from Cellular Polypropylene/Air Composites
Axel Mellinger,Michael Wegener,Werner Wirges,Rajendar R. Mallepally,Reimund Gerhard-Multhaupt +4 more
TL;DR: In this paper, the authors discuss various stability aspects related to the piezoelectric properties of polypropylene ferroelectrets, including the permanent trapping of electric charges inside the polymer voids.
References
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Journal ArticleDOI
Molecular modeling of electron traps in polymer insulators: Chemical defects and impurities
TL;DR: Meunier et al. as discussed by the authors used density-functional theory to calculate trap energies for a set of chemical impurities and additives commonly found in polyethylene used for high-voltage cable insulation.
Journal ArticleDOI
Molecular modeling of electron trapping in polymer insulators
M. Meunier,Nick Quirke +1 more
TL;DR: In this article, the role of defects at the molecular level in electron trapping and the formation of space charge in polyethylene has been investigated, and it is shown that both physical (e.g., conformational defects) and chemical defects may be present in insulating materials and may both trap electrons.
Journal ArticleDOI
Understanding the role of the gas in the voids during corona charging of cellular electret films - a way to enhance their piezoelectricity
TL;DR: In this paper, the influence of the corona-charging process on the piezoelectric transducer coefficient d33 of a cellular electret film has been investigated, and the effect of the gas inside the voids has also been studied.
Journal ArticleDOI
Large and broadband piezoelectricity in smart polymer-foam space-charge electrets
Gerhard S. Neugschwandtner,Reinhard Schwödiauer,M. Vieytes,Simona Bauer-Gogonea,Siegfried Bauer,Joachim Hillenbrand,R. Kressmann,Gerhard M. Sessler,Mika Paajanen,Jukka Lekkala +9 more
TL;DR: In this article, a closed-cell microporous polypropylene foams are shown to exhibit piezoelectric resonance modes in the dielectric function, coupled with a large anisotropy in the electromechanical and elastic material properties.